Talk:Evolution/Archive 54

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Lead evidence sentence

I'm looking at Anatomical, genetic and other likenesses between groups of organisms, geographical distribution of more similar species, the fossil record and the recorded genetic changes in living organisms over many generations, indicate that all life is descended from a common ancestory through a long series of these divergent events, stretching back in a tree of life that has grown over the 3,500 million years of life on Earth. and its variants in recent edit history. I think it confuses evidence of recent (after Cambrian explosion) evolution with a common origin. There is no anatomical similarity between animals and retroviruses for example - the similarity is in the biochemistry. Narayanese (talk) 23:17, 17 July 2010 (UTC)

Hence "and other likenesses". I think we would clutter up the lead by inserting the word "biochemical" after "genetic". Do you have any specific suggestions on how to improve the wording? Gabbe (talk) 08:11, 18 July 2010 (UTC)

Ah, I see now that you were the one who inserted "and other likenesses". I misunderstood what you were trying to say – sorry 'bout that! :) Gabbe (talk) 09:33, 19 July 2010 (UTC)

'Theory' vs. 'hypothesis'

Paragraph 4, first sentence: "...and also develop and test theories".

Should not that be 'hypotheses'?

Kdq (talk) 17:36, 6 August 2010 (UTC)

No. The point of the sentence is to contrast the terms "fact" and "theory". i.e. "Evolution is a fact, and the theory of evolution is an explanation of that fact." There are multiple theories pertaining to the fact of evolution, which scientists have developed and tested over the years.

Jess

_talk
edits

17:50, 6 August 2010 (UTC)

We could say "theories and hypotheses", but although that would be slightly more accurate, it would be a little confusing. Tim Vickers (talk) 17:55, 6 August 2010 (UTC)

But saying "theories and hypotheses" would point out to the reader that the two terms are different. We could always link to an article pertaining to the scientific method for those who are confused. Sepia officinalis (talk) 02:18, 15 August 2010 (UTC)

"Evolutionary biologists document the fact that evolution occurs, and also develop and test theories that explain its causes." OK yes there are new hypotheses being developed but the sentence is worded to referring to the more strongly established theories like gradualism, punctuated equilibrium, ETC. You could add a reference to new hypotheses but this detracts from the central point.Donhoraldo (talk) 16:09, 16 August 2010 (UTC)

Point taken. Looking at it again, "theories" alone does read better than "theories and hypotheses". Sepia officinalis (talk) 19:46, 20 August 2010 (UTC)

Reproduction

How was the transition from asexual reproduction to egg laying and live birth made? I mean reproduction inside the body of the mother that emerged from an egg isn't possible. —Preceding unsigned comment added by 79.118.182.119 (talk) 17:03, 22 August 2010 (UTC)

Have you tried reading about asexual and sexual reproduction, as well as about their differences and similarities?--Mr Fink (talk) 03:03, 23 August 2010 (UTC)

This is not the place to discuss evolution in general, but you are very likely to get good responses if you ask at Wikipedia:Reference desk/Science. Johnuniq (talk) 04:18, 23 August 2010 (UTC)

You might also want to take a look at Viral Eukaryogenesis. --BRPierce (talk) 17:08, 23 August 2010 (UTC)

Misuse of sources

Jagged 85 (talk · contribs) is one of the main contributors to Wikipedia (over 67,000 edits), and most his edits have to do with Islamic science, technology and philosophy. This editor has persistently misused sources here over several years. This editor's contributions are always well provided with citations, but examination of these sources often reveals either a blatant misrepresentation of those sources or a selective interpretation, going beyond any reasonable interpretation of the authors' intent. Please see: Wikipedia:Requests for comment/Jagged 85. That's an old and archived RfC. The point is still valid though, and his contribs need to be doublechecked. Thanks!

I searched the Requests for comment/Jagged 85/Cleanup6, and found 16 edits by Jagged 85. Tobby72 (talk) 21:59, 23 August 2010 (UTC)

Explanation: The edits by Jagged 85 to this article need to be checked. See WP:Jagged 85 cleanup for a quick introduction. The item from the Cleanup6 link relevant to this article is:

Evolution: (16 edits, 5 major, +831) (+268)(+5)(0)(+529)(+11)(+125)(+320)(-1)(+32)(-4)(+8)(+831)(+6)(-1)(-1)(+8)

This indicates that Jagged made 16 edits to this article, and they need to be checked to ensure that any claims are valid, and that any references do in fact verify what is claimed. Johnuniq (talk) 02:51, 24 August 2010 (UTC)

I have quickly looked at each of the edits in question. They all involve the Evolution#History of evolutionary thought section, where the following items were introduced by Jagged 85 (it is the current claims regarding these that needs to be checked):

• People: Empedocles, Lucretius, Al-Jahiz, Ibn Miskawayh, Zhuangzi.
• References:
  • Conway Zirkle (1941). Natural Selection before the "Origin of Species", Proceedings of the American Philosophical Society 84 (1), p. 71-123.
  • Muhammad Hamidullah and Afzal Iqbal (1993), The Emergence of Islam: Lectures on the Development of Islamic World-view, Intellectual Tradition and Polity, p. 143-144. Islamic Research Institute, Islamabad.
  • "A Source Book In Chinese Philosophy", Chan, Wing-Tsit, p. 204, 1962.

Johnuniq (talk) 04:09, 24 August 2010 (UTC)

Yes, this problem is of long standing. As a preliminary: an appreciation of the struggle for life and adaptation is not an appreciation of either natural selection or evolution, though they are both fine natural history observations. The reason is that hundreds of people made the same observations without ever dreaming that evolution had taken place. Most of them thought definitely that supernatural powers created the Earth and all living things. An example is John Ray's Wisdom of God, which is a mine of natural history. It was duly mined by William Paley for his Natural theology of 1902. They are stuffed full of examples of adaptation as a product of God's will.

Therefore, it is absolutely not right to quote ancient writers who wrote on natural history as if they contributed to evolution. The case is somewhat different with Empedocles and Lucretius because they put forward the idea of naturalism, in the sense that things happed for natural reasons, not supernatural.

Well, to specifics. I can see no grounds at all for the link to the Brethren of Purity, and it should come out right away. From my argument above, all the names you list should come out. They are all writers who touch on natural history, but who would not be listed if they were Europeans. We have not listed dozens of European writers on natural history.

There is a case for taking all of these links and the whole section out, and saying "The theory of evolution was first proposed in the 18th century" and go from there (and even that's a concession!). The more you try to accomodate iffy ideas, the less clear the article becomes. Well, I daresay there may not be sufficient agreement to go that far.

Macdonald-ross (talk) 08:41, 26 August 2010 (UTC)

Agree with Macdonald-ross. It's important in the more detailed articles to show that fixity of species was a late development (around the time of Ray, as I recall) and that there were earlier ideas of change and natural developments, but given this doubt why not comment out all the more dubious stuff on non-European until it can be fully checked? I've found that Jagged85 made edits to History of evolutionary thought, and added a heads-up to the talk page with a link here. It seems likely that Islamic philosophy and Science in medieval Islam have also been affected. . . dave souza, talk 09:39, 26 August 2010 (UTC)

I'd also agree with Macdonald-ross that describing natural history, while a key starting point for evolutionary ideas, is not the same thing as describing evolution. Presumably, if this attribution is correct, the listed writers will have written something on evolution (or something akin to evolution) that can be quoted either within the article (perhaps within a citation) or here for assessment. Anyway, is it best to move the "offending" text from the main article to here pending such quotations, or shall we leave it there for the time being? --PLUMBAGO 09:48, 26 August 2010 (UTC)

There is no urgency, but if we put it off, it will never be done. I am weak on history, and hope that Macdonald-ross will take the job of cleaning the section (that is, remove most or all of it). In general, moving text to the talk page can be helpful, but in this case I agree that when people talk about so-and-so providing early insights on evolution, it is usually nonsense. We know for certain that Jagged misused sources (see WP:Jagged 85 cleanup for evidence), so since we are all in agreement, let's just purge the section. Here is an example of "misused" that I found today: Calculus says "Calculating volumes and areas, the basic function of integral calculus, can be traced back to the Egyptian Moscow papyrus" with this source. But the source merely mentions that Egyptians knew a certain formula, and it speculates (in a student exercise) that dividing a volume into small blocks might have led to the formula. So it is complete nonsense to imply that calculus traces back to the Egyptians. When this is done, I hope we can all meet at Talk:History of evolutionary thought#Misuse of sources. Johnuniq (talk) 11:31, 26 August 2010 (UTC)

---

Others who considered evolutionary ideas included the Greek philosopher Empedocles, the Roman philosopher-poet Lucretius, the Afro-Arab biologist Al-Jahiz, the Persian philosopher Ibn Miskawayh, the Brethren of Purity, and the Chinese philosopher Zhuangzi.

← Done. After taking the time to skim WP:Jagged 85 cleanup, I think we can safely remove this sentence to here. If anyone would like to restore it, better sourcing seems key. That, for instance, Lucretius is known for a single work, and our article on this doesn't mention really mention anything like evolution, suggests we need much better sourcing. Cheers, --PLUMBAGO 16:00, 26 August 2010 (UTC)

Well, I've made a further change, to make clear the difference between the origin of scientific thinking generally, and the start of genuine proto-evolutionary thought. Macdonald-ross (talk) 08:10, 27 August 2010 (UTC)

I have checked Science in medieval Islam, and found an even more unrestrained version (of the claims discussed above) in the section headed 'Zoology' Science in medieval Islam#Zoology. Macdonald-ross (talk) 16:33, 27 August 2010 (UTC)

Referencing

I have put a few tags on the lead where statements were made without backing up with sources. One paragraph in particular seemed to be without any references (See below):

(From Evolution article) Evolution is the product of two opposing forces: processes that constantly introduce variation in traits, and processes that make particular variants become more common or rare. A trait is a particular characteristic, such as eye color, height, or a behavior, that is expressed when an organism's genes interact with its environment. Genes vary within populations, so organisms show heritable differences (variation) in their traits. The main cause of variation is mutation, which changes the sequence of a gene. Altered genes, or alleles, are then inherited by offspring. There can sometimes also be transfer of genes between species

--Gniniv (talk) 04:57, 27 August 2010 (UTC)

Gniniv: would it be too much to ask for you to follow internal links to the articles on the "unreferenced" subjects mentioned in the lead and pick some sources from these? I had to do this for you over at Objections to evolution the other day (although I also tracked down some additional sources, so it wasn't a total bust), but I'm reluctant to spend my time sorting out fact tags that you could almost certainly manage for yourself. --PLUMBAGO 07:47, 27 August 2010 (UTC)

I've added some refs. Macdonald-ross (talk) 07:49, 27 August 2010 (UTC)

As have I now (after edit-conflicting with you). Cheers, --PLUMBAGO 07:50, 27 August 2010 (UTC)

I should also add that, though I've just become part of the problem by adding even more sources, the article is already huge and is quite unwieldy to edit. Requests for references that can be satisfied by following a nearby link (often at the same place as the fact tag) are simply frivolous. Especially when you (Gniniv) know they will be forthcoming. --PLUMBAGO 07:59, 27 August 2010 (UTC)

Nevertheless, WP:V still counts, no matter what an editor's WP:POV is...--Gniniv (talk) 02:33, 29 August 2010 (UTC)

@Gniniv I don't know what this is supposed to mean. No one was calling into question your POV. They were quite kindly asking that you find references for statements rather than tagging every sentence you don't like. There is such a thing as "overreferencing". Also, I don't think WP:POV says what you think it does. Jess_talk|_edits 02:49, 29 August 2010 (UTC)

@Mann jess All I am asking (and I believe quite reasonably) that all claims or statements likely to be challenged have peer reviewed sourcing to back them up per WP:V. Is that to much to ask?--Gniniv (talk) 02:56, 29 August 2010 (UTC)

Based on how you're going about it now, yes, it is. You claim that not every controversial statement is cited; there are two ways you could attempt to solve this problem. One (which is what is being asked of you), is to find referencing for the statements you find disagreeable. These are often contained within a linked article, cited in one of the surrounding sentences, or a google search away. This takes only a minute, and solves the problem outright. The other (which you're currently engaged in) is to fact-tag every single sentence you disagree with, without first doing any research. This is disruptive. It doesn't help to improve the article, and it results in drawn out discussions on the talk page like this one, which waste everyone's time. Fact tags should be used when a statement is blatantly controversial, has no citing anywhere around it (including in other sentences), and you can't find a source on your own. It is not to be used to tarnish the reputation of an article which contains information you don't like. Jess_talk|_edits 03:41, 29 August 2010 (UTC)

Thanks for the tip!--Gniniv (talk) 03:46, 29 August 2010 (UTC)

Subjectivity of article

I understand that the idea of evolution is generally considered a "fact" by the scientific community and that there is considerable supporting evidence, but there is also much evidence against, or at least logical improbabilities. I feel that this article in no way makes room for these and declares evolution as the absolute, 100% method by which life appeared on Earth. Being that no one was alive while all of this occurred, or at least did not leave any records, and we cannot travel back in order to confirm our modern hypotheses, I feel there should be some element of subjectivity throughout the article.Mwakin21 (talk) 19:44, 12 August 2010 (UTC)

• I suggest you go through the archives of this talk page; this topic comes up regular as clockwork. Drmies (talk) 19:45, 12 August 2010 (UTC)

If there is evidence supported by reliable sources which disproves evolution, I would love to see it, and I'd be happy to include it in the article. Per WP:V, without sources we can't include that content. If you can find some, feel free to post them here for discussion. Jess_talk|_edits 19:49, 12 August 2010 (UTC)

Your comment is also addressed in the FAQ section at the top of this talk page. Jess_talk|_edits 19:50, 12 August 2010 (UTC)

It's a fairly common misconception that Evolution is in some way related to Abiogenesis, but in reality they are two separate subjects. The Theory of Evolution deals with how life evolved after forming, but does not touch upon the origin of life itself. Also, the article Evolution as theory and fact provides some excellent insight into how those two terms are used in very specific ways. Doc Tropics 20:12, 12 August 2010 (UTC)

With all this said, Mwakin21, you clearly have a major misconception about evolution. "Considerable evidence" is a major understatement. All of biology is unified by the understanding of evolution and there is NO evidence against it. Just like Mann jess said, find some reliable material about evidence against evolution (as a whole). Evolution is not some single lone theory in science, it is a foundation and unifying theory (and fact) of all biology and there are many aspects to evolution that make it a detailed and well-supported theory. Here at Wikipedia, we continually get this kind of talk page discussion like clockwork, literally. The article on evolution is not "subjective". It is very objective, and it would not be science if otherwise. Additionally, if you attempt to source evidence against evolution, creationist material, intelligent design material, apologetics, unscientific resources, and other pseudoscience material will NOT be accepted. It must be scientifically credible material published in peer reviewed journals. Andrew Colvin • Talk 21:09, 12 August 2010 (UTC)

I know it must have come up before but the fact of evolution is that organisms reproduce with variation. this is an empirically observed fact, reproduced countless times in labs all around the world, observed in the wild, and modeled on computers. the theories surrounding this central fact are just inferring what this would do over time, just the same way the acceleration of gravity is a fact and the theory just shows what happens on a larger scale.Donhoraldo (talk) 16:19, 16 August 2010 (UTC)

Hmm. Donhoraldo, you'd have to justify that organisms reproduce with variation. Sexual reproduction produces variation, various forms of conjugation produce variation but essentially some organisms reproduce with negligible or undetectable variation. I wouldn't want it understood that all reproduction produces variation.

Also, we should be saying acceleration due to gravity. Also, gravity is identical on both small and large scales. The effects seem far more impressive with larger masses of course. Candy (talk) 15:09, 28 August 2010 (UTC)

Have you ever seen an organism sexually reproduce and produce a perfect exact copy of itself? I'd love to see the source on that one.SuperAtheist (talk) 19:55, 8 September 2010 (UTC)

The only organisms that I know of where the mother can produce clones of herself via sexual reproduction would be female edible frogs, and female goldfish, where they mate with the males of closely related species, whereupon their eggs become activated by the fertilizing sperm, but then the genetic material donated by the sperm is then rejected and expelled by the egg. Either then, or severely inbred hermaphroditic organisms, particularly if they are forced to self-fertilize.--Mr Fink (talk) 01:40, 9 September 2010 (UTC)

Look up parthenogenesis, this is from the Ambystoma page "However, the Silvery Salamander is completely asexual and does not technically breed. Ambystoma platineum females go through mating rituals with Blue-spotted males in order to begin parthenogenesis, a process known as gynogenesis. They then lay eggs that contain only clones of the mother. Therefore all members of this populations are clonal. Silvery Salamanders may be considered a species, since there is no genetic exchange with any other salamander group, but it is usually classified within Ambystoma laterale. Genetically, they are all one Blue-Spotted-Jefferson hybrid salamander." -Javsav (talk) 01:56, 9 September 2010 (UTC)

Thank you for clarifying.--Mr Fink (talk) 02:05, 9 September 2010 (UTC)

Bdelloidea area also completely parthenogenetic (is that a word?). if jesus was really born by "immaculate conception" (parthenogensis) then logically speaking, since no X chromosone was ever introduced, "he" must have been a female. Kevin Baas^talk 16:50, 10 September 2010 (UTC)

Kevin, I assume you mean, "Y" chromosome. And you know how the joke goes: What does the "H" in "Jesus H. Christ" stand for? Answer: Haploid :D PervyPirate (talk) 09:55, 15 September 2010 (UTC)

If the first one celled organism can find the correct chromosomes, it couldn't be that hard for an all powerful God to. People and their wacky religions.(sorry if this is not a 'Good Faith' comment, I'm new.)--Nishauncom (talk) 10:37, 15 September 2010 (UTC)

The Intro section

Now that I've read the intro again after a long gap, I can see it is quite complex, and tries to move in several directions at once. It is also rather too long. I wonder if there is consensus on a serious attempt to write something more straightforward? The first question, of course, is whether you think my worries are well founded. Macdonald-ross (talk) 08:23, 27 August 2010 (UTC)

I can see what you mean. Notwithstanding my remarks above about the article as a whole, I don't think that it's too long, but it does introduce ideas in an odd order, and could do with being straightened out into something more coherent. Presumably this "jumbling" has occurred as a result of cumulative small changes that, individually, made sense at the time. Yes, I know that's a bit meta for this article, but I think it's the root of what's happened. Anyone else? --PLUMBAGO 09:21, 27 August 2010 (UTC)

P.S. I'm trying to redraft the lead through the recombination of its sentences over here. --PLUMBAGO 16:26, 27 August 2010 (UTC)

← Further to the above, how's about this version of the lead. It's largely just a reshuffling, but I've rewritten it in a few places to restore coherence (my POV). I've also fractionated the text into separate paragraphs that deal with particular concepts. I don't like large numbers of paragraphs (especially in the lead), but where they isolate concepts, I'm happy. Anyway, obviously I think it's an improvement, but what about everyone else? I'd further suggest that we trim reference stacks to the two best sources. --PLUMBAGO 06:59, 28 August 2010 (UTC)

Evolution is the change in the inherited traits of a population of organisms through successive generations. This change is the product of two opposing forces: processes that constantly introduce variation in traits, and processes that make particular variants become more common or rare. A trait is a particular characteristic, such as eye color, height, or a behavior, that is expressed when an organism's genes interact with its environment. To distinguish from other uses of the word evolution, it is sometimes termed biological evolution, genetic evolution or organic evolution.

The main source of variation is mutation, which changes the base pair sequences of genes. These altered genes can be passed on through reproduction, and give rise to alternative varieties, or alleles, of traits in organisms. Another source of variation is genetic recombination which shuffles the genes into new combinations that can result in organisms exhibiting different traits. Under certain circumstances, variation can also be increased by the transfer of genes between species.

Two main processes cause variants to become more common or rare in a population. One is natural selection, through which traits that aid survival and reproduction become more common, while traits that hinder survival and reproduction become more rare. Natural selection occurs because only a few individuals in each generation will survive, since resources are limited and organisms produce many more offspring than their environment can support. Over many generations, the mutations that produce small, random changes in traits, are filtered by natural selection and the beneficial changes successively retained. This iterative process adjusts traits so they become better suited to an organism's environment: these adjustments are called adaptations.

However, not all change is adaptive. Another cause of evolution is genetic drift, which leads to random changes in how common traits are in a population. Genetic drift is most important when traits do not strongly influence survival, particularly so in small populations where chance plays a disproportionate role in the frequency of traits passed on to the next generation.

A key process in evolution is speciation, in which a single ancestral species splits and diversifies into multiple new species, and there are several modes through which this occurs. Ultimately, all living (and extinct) species are descended from a common ancestor via a long series of speciation events. These events stretch back in a diverse "tree of life" that has grown over the 3.5 billion years in which life has existed on Earth. This is visible in anatomical, genetic and other similarities between groups of organisms, geographical distribution of related species, the fossil record and the recorded genetic changes in living organisms over many generations.

Evolutionary biologists document the fact that evolution occurs, and also develop and test theories that explain its causes. The study of evolutionary biology began in the mid-nineteenth century, when research into the fossil record and the diversity of living organisms convinced most scientists that species changed over time. The mechanism driving these changes remained unclear until the theory of natural selection was independently proposed by Charles Darwin and Alfred Wallace. In 1859, Darwin's seminal work On the Origin of Species brought the new theory of evolution by natural selection to a wide audience, leading to the overwhelming acceptance of evolution among scientists. In the 1930s, Darwinian natural selection became understood in combination with Mendelian inheritance, forming the modern evolutionary synthesis, which connected the substrate of evolution (inherited genetics) and the mechanism of evolution (natural selection). This powerful explanatory and predictive theory has become the central organizing principle of modern biology, directing research and providing a unifying explanation for the history and diversity of life on Earth. Evolution is therefore applied and studied in fields as diverse as agriculture, anthropology, conservation biology, ecology, medicine, paleontology, philosophy, and psychology along with other specific topics in the previous listed fields.

Thank you very much for that. It is definitely on the right lines. I will respond in detail as soon as I can. Macdonald-ross (talk) 10:10, 28 August 2010 (UTC)

I just gave it a quick read and ... really like it! But I want to know what other long-standing active editors here (e.g. Tim Vickers, Dave Souza, Get Agrippa) think. Slrubenstein | Talk 11:15, 28 August 2010 (UTC)

I'll comment para by para:

1. You introduce a hostage to fortune when you allow for other uses of the word evolution. I would prefer not to have the last sentence. Needed instead is a mention that at least some of the variation must be heritable.
2. To your three sources of variation needs to be added endosymbiont theory, the idea that eukaryote cells arose in evolution by the fusion of previously free-living protists (prokaryotes). Possible refs: Margulis, Lynn 1998. The symbiotic planet: a new look at evolution. Weidenfeld & Nicolson, London. Sapp J. 1994. Evolution by association: a history of symbiosis. Oxford. Well-established, at least for mitochondria and plastids.
   Needed maybe is a mention of epigenetics, perhaps to say "whether epigenetic changes play any significant role in evolution is not yet clear".
   The mention of lateral transfer of genes needs in particular the reference on bdelloid rotifers: Gladyshev E.A. Meselson M. & Arkhipova I.R. 2008. Massive horizontal gene transfer in Bdelloid rotifers. Science 320, pp1210 - 1213
3. How much you should explain natural selection here is an issue. I find a helpful phrase is differential survival (no charge if you use it!). You will have to change "few individuals in each generation". You mean, of course, a small proportion of eggs laid or born will survive to reproduce..."
4. Drift has been drifting out of favour. Absence of good examples from the field showing evolutionary consequences is becoming embarrassing. Cheetahs, which are so similar to each other genetically that skin grafts can be exchanged (& so must have been 'bottlenecked'), are surviving pretty well despite humans. They are "vulnerable" (IUCN) which is not a critical rating. The wording should read "Drift is most important when populations are very small".
5. OK...
6. The last sentence is a bit iffy, and I would take it out. The main benefit of evolution is its explanatory power. In this intro we should stick to basics.

Thank you again for a good start. Macdonald-ross (talk) 15:16, 28 August 2010 (UTC)

I think what he wrote says that drift doesn't really have big evolutionary consequences (if you mean speciation) and is significant only in small societies. But there is certainly evidence of drift. Slrubenstein | Talk 17:14, 28 August 2010 (UTC)

Para 4 as it stands does represent the majority view. Provine, William B. 2001. The origins of theoretical population genetics. 2nd ed, Chicago. Afterword, item 7, p201, sounds a skeptical note.

Replying to the points above ...

1. In other articles these would be in the first sentence, immediately after the first use of the article's title. Move the names there and lose the rest of the text?

Well, others might not agree, but I think the last sentence should go. A footnote could say "in this article the word evolution means biological evolution, not any other use of the term". Macdonald-ross (talk) 08:53, 29 August 2010 (UTC)

2. I think it could be squeezed in with HGT, since it's kind-of an extreme version of this. Similarly with retroviruses. I guess the sentence could be reworked to get a reference in. Since it is a key process in the evolution of the eukaryotes, it should get a mention.

Some phrase like "Also the rare, but significant, wholesale capture of genomes by endosymbiosis..." perhaps. Macdonald-ross (talk) 07:08, 29 August 2010 (UTC)

3. I'll have a think. I like differential survival too.

4. Don't forget about neutral evolution, which is drift by another name. Molecular clocks (partially) rely on this, and they've clearly been ticking for a very long time. That said, we should be careful not to elevate drift above its station (i.e. it doesn't lead to adaptation), but I can see a role in the lead for it. Trim it back?

I wouldn't say neutral evolution is the same thing as drift, actually, but for drift see my comment above. I accept your para as a majority view. Macdonald-ross (talk) 07:08, 29 August 2010 (UTC)

5. Good.

6. I guess that's the bit where we "make it relevant for the kids". Or something. It could probably be worked into the closing paragraph more naturally.

Anyway, I'll try to fix these points up later. Thanks for taking the time to go through my proposed new version. Cheers, --PLUMBAGO 06:48, 29 August 2010 (UTC)

---

Does anyone have a (well sourced) expansion to those "two opposing forces" mentioned in the lead? I think it would really add to the article if they are delved into with a tad more clarity; instead of just generally mentioning "processes" it could say source what processes and then have more on their active work in the main body of the article....--Gniniv (talk) 02:37, 29 August 2010 (UTC)

Gniniv: the "forces" alluded to are mutation and natural selection/drift, as even a cursory read of the lead reveals. One creates variability, one thins it. Would you like me to spend more time finding sources for these two "cryptic" subjects as well now? --PLUMBAGO 06:32, 29 August 2010 (UTC)

Para 1, 2nd sentence is absolutely fine, and supported by just about the whole of modern evolutionary literature. Its meaning is explained in paras 2 & 3. Perhaps 'processes' instead of 'forces'. Details on any of the topics in the intro should come later. Macdonald-ross (talk) 06:44, 29 August 2010 (UTC)

Actually, I would not say "opposing." They are diferent, I am not sure they are in opposition or what that means in this context. Also, drift is not a force it is sampling error. I am not even sure I would call it a process, but maybe this word is broad enough ... Slrubenstein | Talk 11:06, 29 August 2010 (UTC)

The current sentence says "Evolution is the product of two opposing forces: processes that constantly introduce variation in traits, and processes that make particular variants become more common or rare."

My suggestion is "Evolution is the product of the interaction between processes that constantly introduce variation in traits, and processes that make particular variants become more common or rare." . . dave souza, talk 11:55, 29 August 2010 (UTC)

– in Plubago's proposed wording, substitute "This change" for "Evolution". . . dave souza, talk 12:00, 29 August 2010 (UTC)

Offering this, which takes on board some of the above comments:

"Evolution is the change in the inherited traits of a population through successive generations.[ref] This change is the product of two kinds of process: one kind, which constantly introduces heritable variation in traits, and the other kind, which makes particular variants become more, or less, common".

Alternatively: "Evolution is the change in the inherited traits of a population through successive generations.[ref] This change is the result of processes which introduce variation into the population, and processes which remove it. As a result, particular variants become more, or less, common".

Macdonald-ross (talk) 21:02, 29 August 2010 (UTC)

How about this minor tweak to the second sentence of the last suggestion by Macdonald-ross:

Evolution is the change in the inherited traits of a population through successive generations.[ref] This change results from processes which introduce variation into the population, and other processes which remove it. As a result, particular variants become more, or less, common.

Some other wording would be required to bridge the gap between the "change" used in this para and the "variation" used in Plumbago's next para. Johnuniq (talk) 01:55, 30 August 2010 (UTC)

That might be done by using the form 'inherited variation or 'heritable variation'. It is only the heritable component of variation which takes part in evolution. In this context variation is really a technical term, or has become one, whereas the word 'change' here is ordinary language. Tweak is good, thanks. Macdonald-ross (talk) 07:07, 30 August 2010 (UTC)

← Yikes - that's a lot of commentary. I shouldn't leave it so long next time before replying. Anyway, I've tried to synthesise your suggestions into a new intro draft over here. It isn't wildly different from that above, but I've tried to tweak it for some of the points raised above. If it seems OK, I'd suggest that I replace the current lead with it, so that it can be tweaked more readily. While it's doubtless not perfect, it sounds from the above like it's a definite improvement. Cheers, --PLUMBAGO 16:54, 1 September 2010 (UTC)

I was about to say,'Go ahead'! One major point: your definition of mutation is rather micro. Much bigger things can happen to genes and chromosomes. Indeed chromosome mutations are ubiquitous and important. They are indeed an important source of heritable variation. All Dobzhansky's experimental populations from the wild had chromosome inversions... And I still think the last sentence is hand-waving and only partly true. Nevertheless, I'd much rather see your intro up than leave the present one any longer. Thank you for doing the hard work. Macdonald-ross (talk) 19:24, 1 September 2010 (UTC)

I'd agree about your mutation point. Focusing on base pair changes misses out a number of other changes. Perhaps the wording could be more vague, and just allude to "genetic change" or some such. And I'd also agree about the last point, but I think that I can see what's being said there between the lines, namely that evolution has practical implications. Some sections of society like to pretend otherwise, so I think it's important that it's clear that evolution has tangible consequences. Anyway, I'll sub in my version of the lead, and then it's anyone's to play with. Thanks for all of the feedback! --PLUMBAGO 20:48, 1 September 2010 (UTC)

Thank you. 'changes the base pair sequence' > 'introduces genetic change' would seem to be correct. And moving the 'practical' sentence would be good. The section on Applications itself needs attention, but that can wait for the moment. Meanwhile, do go ahead with those items. I think the introduction is much clearer now, and the effort has brought up some valuable debate. Macdonald-ross (talk) 05:40, 2 September 2010 (UTC)

I need to discuss this before making a change: the sentence "These changes can be passed on through reproduction, and give rise to alternative varieties, or alleles, of traits in organisms" suggests a confusion between traits and alleles. An allele is an alternative version of a gene; a trait may be produced as a result of the action of more than one gene. An allele refers specifically to a change in a section of DNA; a trait is part of the phenotype of an organism. I will adjust to avoid this confusion after others have had a chance to read this. Macdonald-ross (talk) 09:43, 4 September 2010 (UTC)

Now done. Macdonald-ross (talk) 10:14, 8 September 2010 (UTC)

Intro refs

I notice we now have 23 refs in the intro, which might be trimmed a bit. I would start with refs 1, 2, & 15, which seem to be superfluous. Macdonald-ross (talk) 10:14, 8 September 2010 (UTC)

Now done. Macdonald-ross (talk) 13:08, 15 September 2010 (UTC)

Good work. I can't face the intro again just yet! --PLUMBAGO 14:10, 15 September 2010 (UTC)

Clarity

Great job on the intro. I think that it could still use a final polish for WP:Clarity and WP:Use plain English. The wording is still a little abstruse and technical for such a common topic as Evolution. If you could keep the detail that you have added while narrowing down the wordy explanations, I think that would really improve the ability to comprehend what the article is actually talking about.--Gniniv (talk) 05:28, 5 September 2010 (UTC)

Pseudoextinction

Pseudoextinction should be added under out comes of evolution.--Ollyoxenfree (talk) 13:45, 11 September 2010 (UTC)

suggested change to the History of Evolutionary thought section

Suggesting a change of inaccurate wording in the History of Evolutionary thought section.  

Current wording:

The roots of scientific thinking can be dated to at least the 6th century BCE

Suggested wording change:

The roots of naturalistic thinking can be dated to at least the 6th century BCE

This article without the suggested change seems to imply that science was invented in the 6th century. It ignores the reality of pyramids and farming and other forms of science and mathematics that long predate Evolution.Nishauncom (talk) 01:32, 15 September 2010 (UTC)

I think that the problem with this sentence has more to do with the subject of the thinking, evolution or biology, being missing rather than whether the roots of said subject are scientific or naturalistic. Since naturalistic thinking includes non-biological topics, the change above would merely shift the problem to another adjective. I'll edit the text to something like ...

The roots of naturalistic thinking about biology can be dated to at least the 6th century BCE

Cheers, --PLUMBAGO 11:05, 15 September 2010 (UTC)

Thank you for keeping the word naturalistic though; "scientific thinking on biology" may not compute, some may find it a redundancy. Though it is not technically one, when the word scientific is used in reference to Evolution it can be seen as an attempt at unbiasedness.--Nishauncom (talk) 11:25, 15 September 2010 (UTC)

Current Wording

Nowadays, the fact that organisms evolve...

Suggested Change

I'd suggest changing the word "fact" to "theory". It's not an observed fact that macroevolution occurs, as it's never been observed. The LTEE is the closest I've seen to an actual observation, but it lacks a real-world test. Ntr11023 (talk) 15:43, 19 October 2010 (UTC)

There are several problems with this suggestion, as a) the THEORY of Evolution DESCRIBES THE FACTS of Evolution, and that b) macroevolution has been observed repeatedly with the de novo appearances of new species of plants, animals and microbes within the past 500 years That, and if you really want "real world tests," have you ever considered searching on scholar.google for "examples of macroevolution"? Or, if you don't believe that it is a fact that organisms evolve, can you explain why we see so many examples of organisms evolving, such as bacteria developing new genes to enzymatically digest synthetic materials, bacteria, and animals developing resistance to antibiotics and toxins, the development of new breeds of plants and animals, or even the observation of animals changing over generations to better adapt to their environments?--Mr Fink (talk) 16:14, 19 October 2010 (UTC)

Question of Neutrality

"...there are creationists who believe that evolution is contradicted by the creation myths..." This doesn't sound very neutral to me. In fact, it sounds slightly offensive. I hear a hint of superiority from the author, as if he's talking down to people who disagree. I've asked a couple people, and they agree with me. Is it possible that there's maybe a way to write this so that we're not talking down to anyone or giving anyone that impression? Ntr11023 (talk) 15:43, 19 October 2010 (UTC)

That statement is simply a statement of fact. Why is it offensive to state that some people believe that their religious beliefs take priority over science? Can you provide some specific suggestions, rather than implying that we need to coddle Creationist points of view?--Mr Fink (talk) 16:14, 19 October 2010 (UTC)

I agree with the poster. Myth is how I would describe it myself, but to be neutral I think one should say "creation beliefs" or something. Jamie. —Preceding unsigned comment added by 77.44.25.242 (talk) 16:54, 21 October 2010 (UTC)

I think the title of the page should read 'The Theory of Evolution', this would make the content appear more neutral. —Preceding unsigned comment added by Gino1991 (talk • contribs) 19:12, 7 November 2010 (UTC)

Evolution is a fact that is explained by a number of theories. As there is absolutely no evidence against this being true the page is neutral as it stands.--Charles (talk) 19:32, 7 November 2010 (UTC)

See Evolution as theory and fact for more information on why this is the case. Mildly Mad^T_C 19:37, 7 November 2010 (UTC)

Evolution is a fact (and a Theory). See Talk:Evolution #Neutrality Of Scientific Laws, Hypotheses, and Theories. Efiiamagus (talk) 21:32, 7 November 2010 (UTC)

In Our Time

The BBC programme In Our Time presented by Melvyn Bragg has an episode which may be about this subject (if not moving this note to the appropriate talk page earns cookies). You can add it to "External links" by pasting * {{In Our Time|Evolution|p00545gl}}. Rich Farmbrough, 03:14, 16 September 2010 (UTC).

Neutrality

At the suggestion (and almost demand) of John, I will mention this here, instead of using tags that I don't really understand how to use.

This article kind of violates Wikipedia's Neutral Point of View policy. It speaks of Evolution as fact, and yet it is just a scientific theory, not a scientific law. As it says in the rules, and everyone should know by now, Wikipedia's articles should be from a neutral point of view, not by the point of view of a fan, not by the point of view of someone who believes in a certain thing, not by any point of view except neutrality. Just saying.

Anyway, I guess it's not completely my business. Then again it might be. Oh well. --Arkatox (talk) 00:46, 15 October 2010 (UTC)

Evolution as theory and fact explains how the terminology applies. __ Just plain Bill (talk) 00:58, 15 October 2010 (UTC)

I know what evolution is, but I've been looking over the article and (I may be wrong, I was not completely thorough), and it seems to imply the theory of evolution is correct. Oh well, as I said, I wasn't too thorough (I kinda overviewed the article, reading parts here and there). I'm probably just chasing a wild goose. Sometime I'll read through the entire article. --Arkatox (talk) 01:04, 15 October 2010 (UTC)

You do not understand what evolution is if you dismiss it as "just a theory," and assume that this article is violating a Neutral Point of View because we aren't bowing down to religious fanatics who want everyone to worship a literal interpretation of the Bible.--Mr Fink (talk) 01:15, 15 October 2010 (UTC)

Once more, with feeling: Evolution as theory and fact explains how the words "theory" and "fact" apply here. Arkatox, please read and understand it before pressing this any further. If we are going to have a useful discussion, we can't go around saying things like, "You keep using that word. I do not think it means what you think it means." __ Just plain Bill (talk) 01:27, 15 October 2010 (UTC)

"It speaks of Evolution as fact"

As it should and is demonstrable.

"and yet it is just a scientific theory, not a scientific law"

Theories are the explantions of laws and facts.

"and it seems to imply the theory of evolution is correct"

That's because it is.108.15.17.159 (talk) —Preceding undated comment added 06:43, 15 October 2010 (UTC).

You seem very sure of yourself. Because there is sufficient reason to doubt, why are you so quick to establish this theory/fact/whatever-you-wish-to-call-it as absolute, infallible truth? While I do appreciate what much of our scientific community is doing, I am skeptical of many of their practices which are, in my opinion, pure assumption and speculation. Arkatox makes a good point in questioning the neutrality of this article, and I agree. I feel there should be more space for refutation and that the overall tone should change.Mwakin21 (talk) 21:54, 18 October 2010 (UTC)

Do you have an article published in a relevant journal that presents evidence sufficient to call the theory of evolution into question, or are you just so sure of yourself that there is reason to doubt? ldvhl (talk) 22:11, 18 October 2010 (UTC)

Just so. Without a published source giving verification, speculations and opinions have no place in this article, and this is not a forum for such speculation: per WP:TALK, this page is for discussion of detailed well sourced proposals for improving the article. . . dave souza, talk 22:20, 18 October 2010 (UTC)

I didn't mean to start a debate or anything. I was just stating that, regardless of fact, the evolution article is not completely on the neutral side. I in no way meant to state that it is wrong and so on. As was said, this is not a forum. I've been well educated in both creationism and evolution, and I say they both have valid arguments. So just end the controversy on whether or not evolution should be stated as fact (or leaning in that direction), and just leave it as neutral. --Arkatox (talk) 02:37, 19 October 2010 (UTC)

As has been pointed out, we need to adhere to reliable sources and give due weight to ideas according to their prominence. The opinion of our editors doesn't matter; the overwhelming scientific consensus that evolution is a fact and creationism is (at best) pseudoscience does. Jess_talk|_edits 02:47, 19 October 2010 (UTC)

Funny, I thought it was the other way around. It sounds like you've only been educated in evolution, and not creationism. What the heck, I'll just back out. Please don't attack my viewpoint, because most likely I won't answer. Really, I didn't mean to start this. --Arkatox (talk) 02:51, 19 October 2010 (UTC)

No, in fact evolution is accepted as fact by the scientific community and is the basis of pretty much everything in Biology. To me, it sounds like you've not been educated in evolution very well, and I'd advice you to read a good book about it (I can recommend Richard Dawkins' "The Greatest Show on Earth). —Preceding unsigned comment added by 130.37.82.26 (talk) 12:15, 27 October 2010 (UTC)

In a nutshell, the argument of Creationism is that, according to a literal interpretation of the King James' translation of the Book of Genesis, the world was magically poofed into existence 6 to 10 thousand years ago over the course of six 24-hour days. And the only evidence Creationists have ever bothered to use to support this argument have been 1) repeated appeals to ignorance, 2) a plague of repeatedly debunked fallacies, and 3) threats of damnation, ostracism, abuse, and sometimes even violence. Ergo, giving weight towards a Creationism-influenced point of view in this article is a gross violation of Neutrality, especially since there is simultaneously absolutely no evidence for Creationism, AND there has been absolutely no evidence ever found that casts reasonable doubt on biological evolution.

In other words, the tone of this article is absolutely fine the way it currently is, given as how there is no doubt about the validity of biological evolution in the scientific community.--Mr Fink (talk) 02:53, 19 October 2010 (UTC)

Still, favorable points to Arkatox for using the word evolution instead of "evolutionism" or "evolutionist". Thanks for that. __ Just plain Bill (talk) 17:18, 27 October 2010 (UTC)

I'm not sure how this could any more objective. Evolutionary theory/synthesis is virtually unanimously accepted by the scientific community, and per wiki rules, that is how the article should be. I'd be curious about what a 'truly' objective article would be from people who have misgivings about it, and the ramifications of said article would be (for example, for heliocentrism, among other things). Also, evolution is indeed a fact. 68.227.163.169 (talk) 01:40, 29 November 2010 (UTC)

Of Scientific Laws, Hypotheses, and Theories

Arkatox please be aware that Theories never turn into Scientific Laws. Laws are an action or set of actions, or just simple descriptions of phenomena, they are accurate and absolute and they don’t explain why it is so (that is what Theories are for). There is no Law of Evolution nor will it ever be one. Theories are no half made assumptions as you imply; they are completely factual. In contrast an educated guess is a hypothesis, once it has experimental data, it becomes a proven (or disproven) hypothesis. A collection (or just one) of verified and accepted as true hypotheses becomes a Theory. Evolution is no hypothesis it is a Theory with a HUGE collection of general data, empirical data and experimental data. Thank you Efiiamagus (talk) 08:56, 3 November 2010 (UTC)

It's also a very useful computer programming algorithm (see: genetic algorithm ("descent w/modification")). so if you think it doesn't work, well, tell that to my computer. ;-) Kevin Baas^talk 15:54, 3 November 2010 (UTC)

Whether of not Evolution is a genuine Scientific Theory doesn't negate the fact that there are many refutations of it. I think this article would be much more neutral if the information given in each subsection was balanced by the presentation of available alternative views or criticisms of that concept. I appreciate that approach in articles like "Intelligent Design", why use the same balanced approach here? Your article seems to suggest the Evolution Theory is without criticism.

Disagreements are not refutations. There is no scientific controversy about the truth of evolution. There is, however, some religious and social rejection of the scientific facts. Dylan Flaherty (talk) 06:31, 8 November 2010 (UTC)

There indeed are disagreements concerning some the teachings of evolution. As well, there are many scientists who refute them as well. To say there refutations are not scientific may be based on a view that what they say is wrong or "unscientific", but they may also have legitimate scientific refutations. Is evolution not refutable? —Preceding unsigned comment added by Trillium3d (talk • contribs) 06:47, 8 November 2010 (UTC)

No, there actually aren't. Don't confuse Creationism with science. Dylan Flaherty (talk) 06:50, 8 November 2010 (UTC)

Am I to assume that only Creationism seeks to refute evolution theory? There must be other scientific viewpoints out there that question some of the teachings of evolution. Can these refutations not be presented without being categorized with Creation Science? I find it hard to believe that "all" scientists agree with all aspects of evolution, and that any that don't have to automatically labeled as "Creation Scientists".

"There must be"? As it happens, there is no such need. Dylan Flaherty (talk) 07:03, 8 November 2010 (UTC)

Hello. Please be aware that this space is not a forum of discussion; it is a Talk Page for the betterment of the article. If you have any contributions or suggestions on how to make the article better go ahead. Read the FAQ on this page to see why neither a criticism nor a refutation section will be added. Thank You.Efiiamagus (talk) 07:07, 8 November 2010 (UTC)

I think there's a double-negative in there that's confusing me. Are you saying that no such section will ever be added? Dylan Flaherty (talk) 07:14, 8 November 2010 (UTC)

The Magus is saying that this talkpage is for discussions about improving the article's quality only, not for arguments over the validity of the article's subject, as such arguments are ultimately wastes of time that clutter up this talkpage. (I say they're "a waste of time," as, I get the distinct impression that the people coming to this talkpage to question the validity of Evolution(ary Biology) will remain unconvinced of its validity even if God, Himself, descended from the Heavens to personally explain the subject with magic handpuppets)--Mr Fink (talk) 13:47, 8 November 2010 (UTC)

Ok, after the edit, it makes sense. Dylan Flaherty (talk) 02:18, 9 November 2010 (UTC)

It made sense before :D Anyhow it was indeed a subjugated idea of the proper sentence. So I removed it to clarify. :) Take care! Efiiamagus (talk) 17:05, 9 November 2010 (UTC)

People who question whether scientists in general accept evolution as a fact and theory should visit the Wikipedia article on the level of support of evolution. They will find that only 5% of scientist dispute evolution. This was based on a Gallup poll. They should also visit a Gallup Poll page that shows a strong correlation between individuals with less formal education and tendency to have creationist beliefs. I am not trying to be elitist or disparaging but I think such information is quite revealing. People really need to learn more about a subject first before trying to dispute it. mezzaninelounge (talk) 16:22, 9 November 2010 (UTC)

You are correct. However, I just want to point out that the important thing isn't what a Gallup poll says, but what is scientifically verifiable. Even if 95% of scientists told a poll that they denied evolution, it wouldn't matter in this discussion because there would still need to be peer-reviewed scientific studies/experiments/journals/etc presenting verifiable evidence that refutes evolution to justify the article discussing any controversy about its veracity. There isn't any SuperAtheist (talk) 16:33, 9 November 2010 (UTC)

Agree 100% mezzaninelounge (talk) 16:38, 9 November 2010 (UTC)

WP:Lead#Length

The lead of this article is currently six paragraphs; WP:Lead#Length notes that leads should generally not exceed four paragraphs. Shorter leads will naturally leave out some detail, but other featured articles of similar importance and scope -- like Metabolism, Genetics and DNA (and this article before a few months ago) -- have been deemed by the community to adequately summarize their contents with four paragraphs or less. I see no reason why this article should be an exception. Emw (talk) 12:07, 15 October 2010 (UTC)

WP:Lead#Length is only a general guideline to gauge an appropriate size when deciding on which content to include. We shouldn't be removing useful content (and in so doing not adequately summarize the whole article) due to a general stylistic suggestion. Also, the three other articles you point to are more specific than Evolution as a whole. In fact, this article is twice the size of any one of them, and it's to be expected that it has a longer lead to cover all that content. I'm not opposed to shortening the lead if you can suggest an acceptable rewrite. Is there content in the lead you think is superfluous and can be safely removed without impacting the summary? Jess_talk|_edits 15:14, 15 October 2010 (UTC)

The lead has just been through a detailed review and rewrite involving several editors. There is no justification for arbitrary shortening; everything in the intro is necessary. I would ask anyone who thinks otherwise to read carefully the recent discussions. Constant tinkering with material which is in good shape does nothing but harm. Any proposals should be specific, not general. Macdonald-ross (talk) 20:33, 15 October 2010 (UTC)

Here are some statistics that compare the size of the readable text in the lead and body of top-importance featured biology articles:

                    Article  |   Lead                 |    Body                    |    Lead/Body ratio
                    Evolution    4.72 KB; 651 words        62.4 KB; 9,265 words         7.56% (KB); 7.03% (words)
                    (at FAC)   2.64 KB; 369 words         47.9 KB; 6,512 words         5.51% (KB); 5.67% (words)
                    DNA          2.23 KB; 317 words        45.4 KB; 6,837 words         4.91% (KB); 4.46% (words)
                    Metabolism   2.13 KB; 295 words        43.6 KB; 5,579 words         4.89% (KB); 5.29% (words)
                    Genetics     2.51 KB; 355 words        35.9 KB; 5,336 words         6.99% (KB); 6.65% (words)

This shows that the article in its current state is disproportionately top-heavy. I suspect that analyzing more featured articles this way would show that this article's lead-to-body ratio is at least a standard deviation above the norm. The desire to expand introductions to increase their coverage of the subject may come at a cost to readers. It could presumably decrease readers' ability to grasp the subject -- more information may actually decrease the knowledge they retain, and may decrease the overall number of readers. I will try to give specific suggestions on material that could be trimmed later. Emw (talk) 14:47, 16 October 2010 (UTC)

Although I agree with the need to be concise, I disagree with the rationale here. Just because other articles do not have a long lead, doesn't mean we need to trim the lead of this article so that it is consistent with those other articles. Each topic is different and unique. I don't think we should adopt a one size fits all just for the sake of it. When does it end? If other articles have five pictures, must there be only five pictures in this article? There is no evidence to suggest or support the hypothesis that a long lead "will decrease readers' ability to grasp the subject" or that it "may decrease knowledge retained." To test this hypothesis, you would have to ask readers to fill out a survey. The point is that the lead as it stands is fine. It introduces and it explains. It is obviously good enough to be a featured article. My two cents. mezzaninelounge (talk) 15:53, 16 October 2010 (UTC)

There is no formula for determining the best length of a lead. Accordingly, we have to use our judgment, and referring to other stuff is not particularly helpful because many articles are not directly comparable. My judgment is that the lead is good and should not be significantly altered because evolution is a big and complex topic, and I see nothing in the lead that would benefit the article by being omitted. Johnuniq (talk) 00:47, 17 October 2010 (UTC)

Agree with above. The lead length should be as long as needed to appropriately summarize the article, and WP:LEAD is only a guideline. Trimming content just to try to get in line with other articles' leads seems like a needlessly rigid following over guideline, and putting "rules" ahead of writing good articles. Do what works, and the lead, to me, works right now. Barring that, try WP:IAR. —Torchiest ^talk/_edits 12:50, 18 October 2010 (UTC)

An overarching objection I see to adhering to WP:Lead#Length is that evolution is an exceptionally big and complex subject, and thus requires an exceptionally large introduction to adequately summarize its contents. I think there are at least two issues with this rationale:

• A four-paragraph lead was deemed adequate to summarize the article's contents in 2007 during this article's featured article nomination (see here). Since 2007, the topics covered in the the article have remained essentially static: compare the Table of Contents between the article upon its FA promotion the article as of a few days ago (then, now). The sections themselves have expanded -- the readable text in the body of the article has increased by 42% -- but the lead has disproportionately ballooned in size by 76%.
• Virtually all other featured articles on "big and complex" subjects have been deemed to adequately summarize their contents in four paragraphs or less. Consider the following examples from WP:CORE: Bacteria, Fungus, Big Bang, Galaxy, Sun, Law, Poetry and Atom. Also worth mentioning here are good articles in the 'Life sciences and medicine' category of WP:CORE that adhere to WP:Lead#Length: Biology, Cell (biology) and Nature.

Even in its current state, with a lead/body ratio of readable text significantly greater than any other top-importance featured 'Biology' article and well above the upper limit put forth in WP:Lead#Length, the introduction still does not cover (even with a phrase) every topic in the article that's devoted its own heading. Coverage of the 'Coevolution' and 'Cooperation' sections, for example, is absent from the lead. And while the section on 'History of evolutionary thought' is allocated several sentences in the lead's final paragraph, I see nothing that distinctly covers the 'Social and cultural responses' section. If -- as several editors have indicated -- 1) "everything in the intro is necessary"/"nothing in the current lead should be removed" and 2) "adequately summarizing contents" means something like "mention every section in the lead in some way", then presumably those three omitted sections could be mentioned in an additional, seventh paragraph. This would make the lead absurdly verbose, but I think that would be necessary if those two premises were taken to a logical conclusion. To me this scenario demonstrates the worth of putting an upper limit on the size a lead can acceptably be (i.e., that in WP:LEAD#Length), and making sure the central elements of a subject are contained within that limit.

At the suggestion of Macdonald-ross I've carefully read Archive 54 and the discussion there primarily between him and Plumbago, with occasional input from Slrubenstein, Dave Souza and Johnuniq. In that process I also read through the considerably more involved discussion across Archive 52 and Archive 53 primarily between Thompsma, Tim Vickers, and GetAgrippa with input from Slrubenstein and Dave Souza. The lead section produced after the older discussion -- here -- adequately summarized the subject of evolution, and was also more concise than the current version and within the guidelines of WP:LEAD#Length. As can be seen when reading through Archives 52 and 53, there was also a hefty amount of thought put into the one (or two closely related) topics conveyed in each paragraph. Cruft accumulated in the lead between the version by Thompsma et al (in late February 2010) and the version by Plumbago and Macdonald-ross (in late August 2010). However, rather than excising that accumulated material (which wasn't critical) the latter version simply reorganized it and added some of its own, resulting in a lead which is now disproportionate in length, not as focused as it should be, and outside of FA conventions. Given that, I would suggest the lead be restored to essentially how it existed soon after Thompsma et al finished their overhaul around the end of February. Emw (talk) 04:06, 21 October 2010 (UTC)

As explained above, no. Johnuniq (talk) 04:13, 21 October 2010 (UTC)

Johnuniq, I think my reply above takes the points you made on 10/17 into account, but let me address them more specifically:

• "There is no formula for determining the best length of a lead."

Such a formula is precisely what the community has suggested in WP:LEAD#Length, and which other comparable (see below) articles have had no issue following.

• "...referring to other stuff is not particularly helpful because many articles are not directly comparable."

Evolution is certainly a general, important subject within a certain domain, but there are comparable general and important subjects (even some in the same domain) that have no issue following WP:LEAD#Length which I note in the second bullet point in my reply above. How is evolution's "big and complex" nature not comparable to that of the WP:CORE articles listed there?

If there's something in your previous post that was missed in my reply above, please let me know. Otherwise I'd appreciate a response that takes my arguments into fuller consideration. Best, Emw (talk) 04:50, 21 October 2010 (UTC)

At WP:Lead#Length we see "As a general guideline, the lead should be no longer than four paragraphs. The following suggestion may be useful...". I have underlined the text that points out what is well established at Wikipedia, namely that there are no firm rules (per WP:BURO), and guidelines are, well, guidelines. Yes, the Evolution lead is long, and if this article were neglected I would in principle support your efforts to trim it. However, this article is actively watched by many good editors, and the current lead is the result of recent work. I accept your point that the current lead omits some points from the article; my response is that editors in this area have identified what they believe is important for the lead. Rather than approaching this by counting characters, it would be more helpful to identify superfluous material. You have specified this February version as better, and other editors may like to comment on that, but I am happy with the current lead. Johnuniq (talk) 06:38, 21 October 2010 (UTC)

So all I'm getting out of this debate is one editor is freaking out that this article doesn't fit neatly into his spreadsheet formula despite article quality concerns, and everybody else is saying "no". I think it's safe to say there is no consensus to shorten the lead on this article. ldvhl (talk) 12:33, 21 October 2010 (UTC)

I will go along with the "no consensus to shorten the lead" part of that. __ Just plain Bill (talk) 13:26, 21 October 2010 (UTC)

Me too. Going along with "no consensus to shorten the lead." mezzaninelounge (talk) 14:16, 21 October 2010 (UTC)

Agreed. Macdonald-ross (talk) 09:31, 22 October 2010 (UTC)

Same here. I would say a more constructive approach, rather than counting words, would be to continue the discussion of particular bits that could be added or removed to more adequately cover the topic. —Torchiest ^talk/_edits 18:03, 22 October 2010 (UTC)

Hinduism Origins section

While it's interesting that Hindu mythology bears some resemblance to evolution, I'm not convinced that the origins of evolutionary thought can be traced back to them. In the History of evolutionary thought article, there's not even a mention of Hinduism. Sounds like WP:OFFTOPIC to me. Mildly Mad^T_C 22:29, 18 October 2010 (UTC)

I agree. thx1138 (talk) 16:26, 19 October 2010 (UTC)

Avoidance of reference to 'Theory of Evo'

This articles religious avoidance of the word theory made me lol. Is that the purpose of this technique? Imagine someone who's just put his old genetics book back on the shelf (which uses the concept of evolution as a fundimental theory). Then that person comes here, and to check that he's at the correct page by "ctrl+f theory" only to find it nowhere near the bold terminology. After chuckling a great deal, I have to ask, did someone do this as a joke? It's funny and I enjoyed the laugh, but it's kind of unprofessional and obviously a bit distracting.96.18.62.113 (talk) 04:47, 9 December 2010 (UTC)

I laugh at lot too after reading comments posted on here. What a hoot eh. I should point out that the Gravitation article isn't the "theory of gravitation" article. Science and biology describes evolution using theory. The article is about evolution and the theory helps explain the phenomena-just like gravitation has theories of gravitation. Unfortunately the term evolution has become synonymous with the theory-which just isn't correct. It is like arguing gravitation is just a theory. Hilarious isn't it. Regards GetAgrippa (talk) 04:54, 9 December 2010 (UTC)

Lol, it is sad that this religious crusade has bleed into the domain of physics as well, but I would argue that not to have been a consideration for the gravitation page. Their are many physics theories of gravitation and few gravitation theories in the study of linguistics, sociology, theology, etc (this is obviously not so for 'evolution'). I can understand that after so much ridicule predicated on the word 'theory', some followers of biology might become apprehensive regarding the word, but it's unreasonable --and even childish-- for such obsessions to undermine the taxonomy of "the concept of biological evolutionary theory".174.126.195.179 (talk) 17:42, 12 December 2010 (UTC)

This is not a soapbox. Please refrain from discussing personal opinion over topics unrelated to the article. Thanks, A. Z. Colvin • Talk 04:52, 13 December 2010 (UTC)

Continental Drift

Just as a thought, should there be mention of continental drift here and evolution as a proof? —Preceding unsigned comment added by 86.155.51.58 (talk) 16:15, 10 December 2010 (UTC)

There is information on the movement of the continents in relation to the evolution of life on earth over at Evidence of common descent. It is not appropriate for the article on evolution, as it really has nothing to do with principles in geology. In addition, evolution is not technically “proof” of continental drift (tectonic plates). There is of course a “jigsaw puzzle-like” fossil record among the continents, but again, that belongs on the page covering the evidence for common descent (or evidence of evolution as it could be rightly stated). Cheers! A. Z. Colvin • Talk 04:50, 13 December 2010 (UTC)

Diderot history

I was wondering whether Diderot's proto-theories on evolution (in the 1746 "Letter on the Blind", and more developed in the 1769 D'Alembert's Dream) are notable enough to be mentioned along with Maupertuis and Erasmus Darwin in "History of evolutionary thought"? The Diderot article already contains a short note about the 1746 ideas on natural selection. Noamz (talk) 21:58, 17 December 2010 (UTC)

Okay, I see you people are making an effort to keep the article streamlined, so maybe I better ask this question on History of evolutionary thought or Evolutionary ideas of the Renaissance and Enlightenment. Sorry for jumping in... Noamz (talk) 22:09, 17 December 2010 (UTC)

Geology

This has long been one of my favorite articles at WP. But i have been thinking: perhaps the section on the history of evolutionary thought would be improved with a short paragraph on Charles Lyell (sp.?) and James Hutton. I was taught that their arguments about the age of the earth, as well as uniformism, were essential preconditions for the development of Darwin's theories (or, provided grounds that made them so quickly acceptable to most scientists). I am no expert on geology and would not be the right person to craft such an argument, but I think it would help to have a paragraph on how the expanded sense of the age of the earth made Darwin's theory of speciation plausible, and establishing geological uniformism (uniformitarianism?) was an important part of extending some of the basic principles Galileo and Newton applied to the physical world to the natural world, thus setting the stage for Darwin. I am sure this can be said more concisely and elegantly and would strengthen this section. Slrubenstein | Talk 12:20, 8 December 2010 (UTC)

Both the work of Lyell and Hutton raised challenges to Cuvier's explanation for the fossil record via catastrophic events. The idea of both gradual and slow changes as it effects geological formations is what gave Darwin the "time" needed to justify dramatic differences via natural selection. I agree, they are a big part of most lectures on Evolution. Perhaps it could be worked into the Section on History of Evolutionary Thought.--JimmyButler (talk) 18:33, 8 December 2010 (UTC)

Agree. Add the material and lets try to work on it. It is an important addition. Doesn't need to be perfect at first. -Efiiamagus (talk) 20:29, 8 December 2010 (UTC)

Great idea! Perhaps mention Cuvier and Linnaeus (taxonomy and species idea) then Lyell and Hutton's influence on Darwin. Beside Wallace didn't Darwin also recognize Well's and Mathews as contributors to the ideas of natural selection???? Darwin's journey and biogeographical experiences and observations helped mold his ideas too. Work up to the modern synthesis and phylogenetic systematics. GetAgrippa (talk) 04:41, 9 December 2010 (UTC)

Allright. As a prelim, let's remember that the article clocks up 161KB, and even the History of evolutionary thought clocks up 95KB. I cannot see we should increase the present overall size (except minimally), and my first conclusion would be that if we wish to add more geological context, then someone needs to suggest areas which could be slimmed. I do ask regulars to comment on this principle first.
Next, I do agree that the geology input to the article is undercooked, and could be usefully increased. Also I think that applies to the sub-page History of evolutionary thought, which also is sketchy on earth science.
Thirdly (after others have had a chance to repond) I suggest we operate as before by making specific suggestions here, not on the page 'til we have a consensus. Macdonald-ross (talk) 12:30, 9 December 2010 (UTC)

I cannot propose any cuts, but what I am calling for would only be three or four sentences - their discoveries, what they concluded, what made their conclusions so important and how they influenced or helped Darwin. for the sake of this article, each of these points can be made concisely, in no more than a sentence each. (so, regrettably, I would not put in Cuvier and Linneus ... people following links to Lyell and Hutton could reach Cuvier if they wanted to dig.) Slrubenstein | Talk 13:56, 9 December 2010 (UTC)

I agree and wouldn't cut anything either. I also agree including Lyell and Hutton and let subarticle link to Cuvier. I guess Aristotle proposed a similar notion of species similar to Linnaeus, but still the idea of nomenclature and categorizing organisms seems appropriate. I'm not particularly of a strong opinion either way. GetAgrippa (talk) 21:09, 9 December 2010 (UTC)

The following was lifted from the Introduction to Evolution and edited slightly to reduce length. The approach there was to develop an understanding of the process following the time-line or historical perspective. A very different approach in the main article; so I'm not certain that this section can be reworded to fit in without adding too much bulk. However, there may be tid-bits in it that can be incorporated, at least so that the key names can be linked to their more expansive articles. A sand box might be appropriate - be BOLD - but systematic, seems to be the message from Macdonald-ross Cheers!--JimmyButler (talk) 15:02, 9 December 2010 (UTC)

• Modern paleontology began with the work of Georges Cuvier (1769–1832). Cuvier noted that, in sedimentary rock, each layer contained a specific group of fossils. His observations revealed that many forms of life from the past are no longer present today, establishing extinction as a fact. Cuvier proposed the idea of “revolutions” or catastrophism in which he speculated that geological catastrophes had occurred throughout the Earth’s history, wiping out large numbers of species. Cuvier's theory of revolutions was later replaced by uniformitarian theories, notably those of James Hutton and Charles Lyell who proposed that the Earth’s geological features were the product of millions of years of gradual and consistent changes. However, current evidence in the fossil record supports the concept of mass extinctions. As a result, the general idea of catastrophism has re-emerged as a valid hypothesis for at least some of the rapid changes in life forms that appear in the fossil records.

My proposal, aiming only at brevity: In the early 19th century, Charles Lyell drew on discoveries by a number of natural historians to argue that unlike the prevailing reading of the Bible, which held that the creation of the Earth occured at once and in the recent past, the Earth is in fact quite old, and continues to be reshaped by the same forces that have been at work since it first took form. Lyell's work influenced Darwin and his supporters in two critical ways. First, his "uniformitarianism" suggested to Darwin that processes acting on members of species today could be the same processes through which diferent species emerged in the past. Second, the extreme age of the Earth allowed sufficient time for hosts of species to evolve, become extinct, and b replaced by new species.

I do not claim this is perfect, but I do claim that it is enough to establish the contribution of geology to Darwin's thought. I think the relationship between catastrophism and uniformitarianism in geological history versus biological history is at best complex, too complx to raise in this context. This is a section on the history of the development of evolutionary theory, so all that is important is what people believed in 1830s, 1840s, and how that influenced Darwin. The article later on addresses gradualism versus punctuated equilibrium. I happen to think these are not identical to uniformitarianism and catastrophism, but that is neither here nore there - contemporary debates among evolutionary scientists belong in later in the article and not in th section on the development of Darwin's ideas. Slrubenstein | Talk

This is a can of worms, as the background is complex and commonly misrepresented. The prevailing reading of the Bible among Christian geologists in the 1820s was a sort of day-age approach in which they were very aware of the vast lengths of time shown by geological stratigraphy, and were confident that true inductive science would reveal that to be consistent with the real truth of the Bible. Early geologists including the influential Werner proposed Neptunism with shrinking oceans over a huge timescale, that directional prehistory was disputed by Hutton (and later Lyell), who proposed an infinite cycle, no vestige of a beginning and no prospect of an end. Catastrophism proposed an explanation of past eras, and in the outcome of the argument was an amalgamation rather than the simplistic victory for uniformitarianism presented in Lyell's rather distorted history. Evolutionary ideas predated Lyell, and Hutton had limited influence. Of course uniformitarianism greatly influenced that well known geologist Charles Darwin, but only after he'd already been impressed by the vast eras of time proposed by his tutor Adam Sedgwick who epitomised the combination of advanced geological ideas and anti-evolution common among English scientists at the time. . . dave souza, talk 23:58, 9 December 2010 (UTC)

I do no tclaim what I wrote is perfect, and have no objection to people editing it or proposing alternatives. What I do feel strongly about is that the "History" section have a few sentences on how Lyell influenced Darwin and why Lyell's work (without denying credit to others) was so important for Darwin's theories to catch on so quickly among so many scientists. Surely there is a way to say this that won't take more than a short paragraph? Slrubenstein | Talk 01:32, 10 December 2010 (UTC)

I have to agree with Slrubenstein that we would be remiss to leave out the influence of Lyell. After a 9 year retirement I'm back teaching (the economy), I am presently teaching a survey biology course (Campbell) and they emphasize the influence on Darwin too. Seems this level would be appropriate for an encyclopedic article. GetAgrippa (talk) 12:56, 10 December 2010 (UTC)

Does punctuated equilibrium (linked in the article) have a place in this discussion? Question is, is it well-enough accepted to have a place alongside mention of catastrophism and uniformitarianism? __ Just plain Bill (talk) 14:35, 10 December 2010 (UTC)

I do not think so. Punctuated Equilibrium is not the same thing as Cuvier's theory of catastrophes, which was about the formation of geological features, not speciation per se. We are talking about an edit to the section on the historical background of evolutionary theory, and specifically, an influence on Darwon (i.e. a paragraph to go right before the paragraph on Darwin and Wallace). To bring up punctuated equilibrium woud be wrong for two reasons: first, it would be anachronistic, as the model did not exist before Darwin or influence Darwin, and second, because the article should deal with PE as an important model in neo-Darwinism/modern synthesis ... but one that was proposed in the late 20th century. It doesn't belong in the history section, PE should be discussed in some detail later in the article. To bring it up in the history section and then to discuss it later would be redundant and we cannot afford to waste space.

GetAgrippa, perhaps you can improve on what I proposed and then unless anyone objects we can put it in. As someone else pointed out earlier, any addition we make needs to be kept short. Slrubenstein | Talk 15:26, 10 December 2010 (UTC)

Regarding PE, thank you. Makes perfect sense to me, particularly in the light of a large article. __ Just plain Bill (talk) 16:28, 10 December 2010 (UTC)

I am glad we agree. I certainly think PE should be discussed somewhere in the article, just not in this particular context. Slrubenstein | Talk 17:16, 10 December 2010 (UTC)

• Regarding the influence of geological ideas, I commend to your attention On the Origin of Species#Developments before Darwin's theory. Firstly, it may be worth noting that the early Christian Church Fathers and Medieval European scholars interpreted the Genesis creation myth allegorically rather than as a literal historical account; organisms were described by their mythological and heraldic significance as well as by their physical form. Nature was widely believed to be unstable and capricious, with monstrous births from union between species, and spontaneous generation of life. Both the concept of fixed species and the literal counting back to Creation came with the Reformation. So, in relation to geology;
  The Ussher chronology of the 1650s had calculated creation at 4004 BC, but by the 1780s geologists assumed a much older world. Wernerians thought strata were deposits from shrinking seas, but James Hutton proposed a self-maintaining infinite cycle. Georges Cuvier's paleontological work in the 1790s established the reality of extinction, which he explained by local catastrophes, followed by repopulation of the affected areas by other species. Geologists such as Adam Sedgwick adapted catastrophism to show repeated worldwide annihilation and creation of new fixed species adapted to a changed environment, initially identifying the most recent catastrophe as the biblical flood. In opposition to this view, Charles Lyell adapted Hutton's concept into a stricter uniformitarianism which strongly influenced the young geologist Charles Darwin during the Beagle expedition. Darwin initially followed Lyell's idea of repeated "centres of creation" of fixed species, but questioned Lyell's views and in 1836, near the end of the voyage, he expressed doubts that species were fixed. By the end of 1838 he had developed his concept of natural selection to explain how species formed.
  That's rather closely focussed on geology, we also need to cover developing ideas of transmutation of species. These are also shown in On the Origin of Species#Developments before Darwin's theory. There's a danger in this account being rather Anglo-centric, Hutton and Lyell had less influence on the continent, and idealist Germans such as Goethe and Oken developed their own sort of proto evolutionary ideas. . . dave souza, talk 20:49, 10 December 2010 (UTC)

Dave, this is much longer than I intended - but (as usual) you did a superb job of research and writing. I have no problem with this; I think it adds important context for Darwin to the history section. I have no problem with what you call its "anglo-centrism" - I think what is essential is context for Darwin, and we neeed to be selective about what we consider essential. Of course the history section in this article is partial, but I believe details about Goethe and Oken and others belongs in a separate history of evolutionary theory article, and is not necessary for this article. Still, I would like to know if GetAgrippa or Jimmy Butler approve, or suggest any edits ... but if they like it as much as I do I hope we can add it to the historical background section! Slrubenstein | Talk 22:00, 10 December 2010 (UTC)

Okay, it has been a couple of days with no further comment, I will add this to the article and others can suggest improvements if they see any. Thanks Dave! Slrubenstein | Talk 13:43, 13 December 2010 (UTC)

but James Hutton proposed a self-maintaining infinite cycle. Is that Plutonism? If so, then perhaps it can be linked as such so that the reader might better grasp "self-maintaining infinite cycle".--JimmyButler (talk) 15:37, 13 December 2010 (UTC)

We link James Hutton which includes his theory of the Earth – Plutonism appears to me to be more to do with proposing volcanic actions as forming rocks such as granite, and causing uplift of the land. Earlier Plutonists such as Moro don't seem to have had the concept of an infinitely repeating cycle promoted by Hutton and in turn by Lyell. . . dave souza, talk 16:09, 13 December 2010 (UTC) ... ref: Morus, Iwan Rhys; Bowler, Peter J. (2005). Making modern science: a historical survey. Chicago: University of Chicago Press. pp. 120–124. ISBN 0-226-06861-7.{{cite book}}: CS1 maint: multiple names: authors list (link) . . dave souza, talk 17:01, 13 December 2010 (UTC)

Noted - thank you for the clarification.--JimmyButler (talk) 19:56, 13 December 2010 (UTC)

Thanks, Jimmy and Slr. Have tried some successive tweaks with the aim of improving the flow, and clarifying the early context. We should be aware that species weren't defined or seen as fixed until after the Protestant Reformation, so that evolutionary ideas then developed in contrast to that relatively recent concept of fixed species. The references for this can be found at On the Origin of Species, presumably we want these paragraphs to be fully referenced in this article so will aim to get that done if everyone's reasonably content with these changes. It's a condensed version of that account, so may be worth checking if any important aspects have been left out. . . dave souza, talk 23:20, 13 December 2010 (UTC)

Dave, the following: The Ussher chronology of the 1650s had calculated creation at 4004 BC. Is there any way that can be expanded to identify this as based on the theology? I'm uncertain whether it was key events in the bible or genealogy (or perhaps both); but most readers have no clue of the religious connection. More words in an already lengthy article - always this topics bane! Perhaps 4 more words: The Ussher chronology of the 1650s, based on Christian Theology, calculated creation at 4004 BC. Cheers --JimmyButler (talk) 00:10, 14 December 2010 (UTC)

Good point, I think "Bible based" covers that so have added those two words. Ussher chronology provides the detail for anyone who's interested. Thanks, dave souza, talk 01:09, 14 December 2010 (UTC)

You're right that Ussher was not an issue for 18th C. geologists; and he was not so significant even for 17th C scientists (I've just checked with biogs of John Ray and Robert Hooke). Another 16/17 C issue which was solved by the 18th C was whether fossils were the remains of living things.
On the influence of Lyell on C.D. I would rate highly the simple fact that he wrote the best textbook of the day; in other words, it was the application of gradualism to actual cases which was influential. Darwin, who lacked formal teaching in geology, took the first volume of Principles on the Beagle. It paid off more than he could have imagined. Macdonald-ross (talk) 11:01, 15 December 2010 (UTC)

Thanks for checking up on Ray and Hooke. It's worth considering working in a brief mention of Ray's definition of species as the first biological definition, inherently defining species as unchangeable.
Regrettably, I feel the urge to quibble a bit. We should perhaps be aware that even though clergymen geologists were convinced that the Earth was older than the Ussher dating, some other clergymen continued to argue for a young Earth, notably William Cockburn, Dean of York, in his 1844 debate with Adam Sedgwick.
Geology appears to have been an extracurricular subject in the universities of the time, but Darwin received significant teaching. During his first year at Edinburgh he attended the chemistry lectures of Thomas Charles Hope which, according to Secord, included promotion of Hope's Huttonian views in contrast with Neptunism, then in his second year took Robert Jameson's natural history course which gave him a solid, if rather boring, grounding in mineralogy as well as field visits enlivened by attacks on Plutonism. Apparently he made considerable use of Jameson's textbook on the subject, marking it up with reference to specimens in Jameson's extensive museum where Darwin worked on various subjects.
At Cambridge, his close friend and tutor Henslow was a geologist as well as a botanist. There's evidence that Darwin learnt from Sedgwick between Spring and July 1831, so after helping Sedwick's fieldwork in Wales, Darwin had been "briefly but well trained in the field". See Herbert's Charles Darwin, Geologist pp. 32–39, some of which is covered in her online paper, pp. 171–174 in particular.
Also note, that Darwin was given Lyell's first volume by FitzRoy, rather than taking it himself, though his tutors had made him aware of the book. Rather too detailed for this article, but interesting. . . dave souza, talk 20:58, 15 December 2010 (UTC)

Thank you for various leads, which have lead me round to thinking that the case for C.D. being 'trained' is probably better than I had thought (so the basic content of the section should stay more or less as it is). In reading about Cockburn I ran across Scriptural geologists, which others might enjoy. It enters on the theme of what they thought of each other, or, when is a geologist not really a geologist.
I was a bit taken aback by the long, involved sentences and paragraphs, so I did a bit of paragraphing. This threw up the discussion of the word 'evolution' as being out of place, and that we did not list the phrases which were used by C.D. and others to mean what we mean by evolution. Is this something we feel should be tackled? Macdonald-ross (talk) 17:55, 16 December 2010 (UTC)

I'm beginning to wonder just how YEC Cockburn was, but he was clearly among the Scriptural geologists and was arguing against Sedgwick's view of past ages. Interestingly, in 1838 Charles Babbage wrote "The Church of England, if we may judge by the writings of those placed in authority, has hitherto considered it to have been expressly stated in the book of Genesis, that the earth was created about six thousand years ago. 2dly. Those observers and philosophers who have spent their lives in the study of Geology, have arrived at the conclusion that there exists irresistible evidence, that the date of the earth's first formation is far anterior to the epoch supposed to be assigned to it by Moses; and it is now admitted by all competent persons, that the formation even of those strata which are nearest the surface must have occupied vast periods—probably millions of years—in arriving at their present state." As for the naming issue, see below: Darwin may well have been aware of the term as used by his informal tutor Grant, but in view of the way that Grant's reputation was blackened by Owen and others may have thought the term too disreputable. Am sure someone's written about it somewhere. . . dave souza, talk 17:22, 18 December 2010 (UTC)

First use of "evolution" in modern sense

Having found that the source is available online, I've added a detailed explanation and extended quote to Charles Darwin's education#Lamarckian anatomy. Couldn't resist adding a brief summary here, with sources, but it's a bit out of sequence so others may wish to review it. The extended quote could arguably go in other articles [as well?] such as Grant's bio, but given the disputed attribution a bit difficult to say where's best: perhaps a new article on the Edinburgh New Philosophical Journal which at present is a redirect. . . dave souza, talk 17:22, 18 December 2010 (UTC)

ID

You will be maybe, interested by this text ?

Evolution of Species

1. Potential state and actualization of potentialities (their materialization for becoming realities)

- Why (how) ceaseless creative activities that take place within singular domain where are memorized the genetic programs, have led to omnipresence of a bacterial world almost unchanged since about three billion years, and also, to emergence of men ?,

- what can we say about the activities that cannot be "fossilized", notably the ones which enable recognitions, judgments, selections, anticipations,…, and which express themselves by associations, agreements, harmonies, symbiosis, … ?,

- how to explain dynamics of the bacterial world which ignores basic principle of the evolution : every species progresses to reach a superior complexity ?,

- can we understand apparent superiority of certain beings of "small sizes" in front of life's constraints ?,

- why 80 % of the multicellular beings, the arthropods, in spite of their particularly rapid development, have not a propensity towards nervous complexity ?,

- what can we say about the potential overcapacities acquired, notably overcapacities to react and to protect itself ?,

- why (conscious) creativity of our distant ancestor, was so primary when he had intellectual and sensory organs comparable to ours ?

It was some main interrogations and facts which show evolution of species as correlative of ceaseless creative activities, and, also, as correlative of actualizations (materializations) of potentialities, notably genetic,

and it, in spite of, sometimes, insuperable constraints.

That is why we recognize to individuals of remarkable lineages, a “genetic potential”, not only which is characteristic of their complexity level, but also which can increase by means of ceaseless creative activities until to attain, in particular circumstances, critical points (critical thresholds) at origin of sudden evolutions.

Let's quote other facts which give a credibility to this understanding :

- the adaptations to the environment by means of polyvalent genetic transformations which are representing of new potentialities (named exaptations by Gould and Vrba),

- the nucleotidic substitutions which are active when new environmental constraints appear (notably, that is why in the evolutions of species, there are of numerous successive periods of stability and of adaptations to the environment) ; so, more or less long periods of adaptation to the environment, correspond to lapses of time which are necessary for actualizing (so that become realities) the genetic potentialities.

- the increases of structural complexity by means of common biological entities to all beings, and which characterize the remarkable lineages,

- the resemblance between some evolutive processes of the life's phenomenon and of the inert matter ; for example at the time of complexity's increases, between the bipolarity of the sexual reproduction mode and bipolarity of phase's transitions in the inert matter.

In reality, the periods of stability are illusory.

Life and world are fruits of continuous creations !

Moreover, the ceaseless creative activities do show that natural selection and adaptation to environment are not primordial causes which led, which lead to evolution of species.

As for phenomena which are said aleatory facts or fruits of the hazard :

who effects the coherent and necessary selections for surmounting inevitable extinctions which are consequences of the aleatory regroupings ?

The hazard ?

Certainly not !

2. The interpretation, an absolutely necessary and universal process.

Do you believe for example, that the relational process between proteins and RNA (or a part of this one) can be expressed and explained only by means of some physical-chemical-mathematical formalizations ?

Evidently not, because, for example, necessary "processes organizations" for "body's construction", which are coded and memorized on a molecule of about "10 power minus 12" gr, must be interpreted (recognized, judged, …) as are, in human language, the letters, the words and the sentences.

Consequently, in a research of primordial causes, we cannot keep silence as for these interpretations,

and more precisely, we cannot ignore interpretation of electromagnetic waves's characteristics which are the vectors of biological processes organizations,

these electromagnetic waves which emanate of the particles, atoms and molecules constituting DNA and ARN,

under pretext that this process don't emerge from consciousness state.

The biological mutations are rich of information in this respect, if we interpret with more rigour, the current scientific speeches that treat of them.

Let's quote text of Michael Denton,

" two new discoveries :

- mutations's rhythm is equal to substitutions's rhythm …,

- change's rhythm, in case of numerous genes, is punctuated by a clock that is rotating, it seems, synchronically in all branchs of the life's tree … doubtless the proof, indirect, that all mutation processes which are changing the DNA sequences in the time, are led in fact, by some mechanism …

It is not doubtful that Gray, Owen and especially Robert Chambers would have seen in these results very strong arguments in favour of idea according to which evolution's course is determined, in some way, by a natural law." (cf. The Long Chain of Coincidence).

To interpret with more rigour, yes, because, we repeat again, a law, natural, even universal, is not an operator.

To analyze other biological processes would consolidate hardly more our argumentation.

Actually, all evolution modes of the life's phenomenon presuppose,

- and the use of numerous value references ; let's think for example, to references which are necessary for coherence, development and replication of the genetic patrimony : " high - down", "forward - back ", "right - left", .... ,

- and the elaboration of information and of processes organizations at the molecular level,

what, naturally, implies faculties similar to those which enable, at the conscious level, recognitions, judgments, selections, ..., decisions and actions.

The scientific speeches cannot mask any more these essential facts.

What can we say about creative entity, "master of the sense", who recognizes them, who uses them ?

Main part of this theory is deposited at Academy of the Sciences, in Paris, into sealed envelope n°17611

Paul Moyne —Preceding unsigned comment added by 109.212.250.248 (talk) 19:56, 31 December 2010 (UTC)

Thanks, Paul, the name Michael Denton sheds some light on your thoughts. This may be relevant to articles on intelligent design and teleological argument, but not here, and would require a reliable third party source to avoid original research. . . dave souza, talk 22:35, 31 December 2010 (UTC)

Multi-level selection - where are you??

It has been a while since I have visited this article and I just had a read through. For some reason this article keeps going back to the reductionist Dawkin's style of evolution and doesn't convey evolutionary theory as it has progressed in the scientific literature. Many evolutionary biologists have always held that evolution was a multi-level pluralistic process (Sewell Wright, George Simpson, Conrad Hal Waddington, Lynn Margulis, Ernst Mayr, John Haldane, and Stephen J. Gould - to name a few of the most notable figures in this respect). I don't have the energy or the time to come back here and battle this out, but I find it quite disappointing that the article presents a bias away from evolutionary theory as it is presented in much of the scientific literature. There is a slight deflection away from the reductionist approach by reference to traits, but the rest of the article sways strongly in favor Dawkin's evolutionary thinking or style - otherwise encompassed under the modern synthesis. For example, the first sentence in the second paragraph in the lead states: "The main source of variation is mutation, which introduces genetic changes." - this is false (or misleading - it is the main source of genetic variation). The main source of 'phenotypic' variation is not mutation, but the complex juxtaposition and interaction among characters being expressed in a multi-dimensional epigenetic landscape. If you understand the concept of Rupert Riedel's burden from developmental biology, you can further argue that the main source of variation is not mutation, because the evolvability of a system is dependent upon burdened sub-components.[[1]][[2]]

The one place where the article introduces epigenetics states the following: "Another unsolved question in genetics is whether or not epigenetics is important in evolution. Epigenetics is when a trait is inherited without there being any change in gene sequences." - This is completely false!! Not only is that poor definition of epigenetics, it is also not an unsolved question - geneticists have known full well for a long time (since the 1940's!!) that epigentics has a pivotal role in evolution and this is another example of where this article presents a biased perspective. I already argued these points last year in this discussion page - many of us struggled to make some changes, but here we are back at square one. Here is a quote from a recent article in Nature (http://www.nature.com/nature/journal/v465/n7299/full/nature09230.html): "Epigenetic modifications of DNA and histones might be crucial for understanding the molecular basis of complex phenotypes." - this doesn't sound unsolved or unimportant. Epigenetics is a cornerstone of modern genomic research.

The extension away from the gene is not a new direction either. "It is an incontestable historical fact that embryology and developmental biology—highly sophisticated disciplines with a long history of their own by the time of the Modern Synthesis (MS)—have simply been left in the cold.Nomajor developmental biologist contributed to the MS, despite early forceful endorsements of Darwinism by leading figures"[[3]] Waddington was writing about epigenetic phenonmena in the 1940's, Sewall Wright was writing about epigenetic and species levels of selection back in the 1960's (possibly earlier, e.g., The American Naturalist Vol. 63, No. 686 (May - Jun., 1929), pp. 274-279 ) and German morphologists were discussing this even earlier. For example,

At the time Rupert Riedl started his work on the OLO (‘‘Order in Living Organisms: A systems analysis of evolution’’) a number of authors had already developed ideas that sought to extend the dominant Neo-Darwinian paradigm of evolutionary theory to include macro-evolutionary and developmental perspectives. Most notable are the widely discussed works of Waddington (’57), as well as the books by Rensch (’59) on evolution above the species level (German edition, ’47), Simpson (’53) on the major features of evolution, and Stebbins (’74) on plant macro-evolution. But it was not until the late ’70s that attempts were made to broaden the evolutionary synthesis by systematically including developmental biology and macro-evolution.(Wagner & Laubichler, JOURNAL OF EXPERIMENTAL ZOOLOGY (MOL DEV EVOL) 302B:92–102 (2004)[[4]]

There is a serious problem with the 'neo-Darwinian' synthesis, because it is incapable of providing a proper explanation for patterns that occur at the level above the gene (i.e., epigenetic) (see http://a-c-elitzur.co.il/uploads/articlesdocs/Jablonka.pdf). Philosopher Karl Popper recognized this when he stated that “the [Modern Synthesis] is strictly a theory of genes, yet the phenomenon that has to be explained is that of the transmutation of form” (Platnick and Rosen 1987). The last time I came in here to debate this we had pages and pages of difficult debate, so I don't want to go there again. However, it is truly a shame that the article keeps regressing. There is no mention of evo-devo - despite its vast popularity since the 90's nor is there any mention of niche construction - which has ballooned in citation rates - both these areas give a different perspective on evolution than is being presented in this narrow focused article. A recent article in evolution (Eldakar, O. T., Wilson, D. S., Dlugos, M. J., & Pepper, J. W. (2010). THE ROLE OF MULTILEVEL SELECTION IN THE EVOLUTION OF SEXUAL CONFLICT IN THE WATER STRIDER AQUARIUS REMIGIS. Evolution, 64(11), 3183-3189.) is testament to the broader scope of evolutionary thinking in the very journal where this science is being discussed. Furthermore, I quote from a most recent article to appear in evolution,

But of course the meat of the matter for the critics of the Modern Synthesis is not the evolution of the phenotype from standing variation or even its evolution from the mutation matrix but the forming of the phenotype, or developmental evolution. Here the claim is very specific that either the Modern Synthesis is insufficient, or as Newman suggests in this volume, perhaps not even necessary for explaining the appearance of complicated features like multicellularity or novel body forms. (Travis, J. (2010). THE MODERN SYNTHESIS AND ITS POSTMODERN DISCONTENTS. Evolution, in press.)

I realize this is not a textbook, but why can't there can't be some form of compromise that would explain some of the parallel developments in the spirit of Darwin's pluralistic approach? I notice on the bottom of the page that there is a link to Current research in evolutionary biology, but this doesn't cut it very well - namely because many of the developments I'm referring too are not of recent origin, but paralleled the development of the 'Neo-Darwinian' synthesis through history. Under the section on cooperation there is one sentence on group selection - yet this has been a central component of evolutionary debate for the past one hundred years!![5] Here is what Sewall Wright (one of the most prolific evolutionary writers and pre-eminent founders of the modern synthesis) had to say:

I am not in a position to discuss independently the data of paleontology and recognize that my field, genetics, bears directly only on microevolution, but I feel that we should explain phenomena at the higher levels as far as possible, as flowing from observed phenomena of genetics in the broad sense, including cytogenetics, before postulating wholly unknown processes. This does not bar me from accepting selection among entities at all levels of the biological hierarchy.[6]

Since Wright published that article in 1982, much research has been done, published and demonstrated that there are causal processes for selection acting at levels of the biological hierarchy other than genes alone (for example, [7]). Moreover, in order to put Wright's thoughts into perspective it is important to note that he accepts cytogenetics into the microevolutionary umbrella. This means that he accepted communties of genes packed into chromosomes as a causal unit. Wright had an epigenetic perspective on the relationship of genotype to phenotype that differs substantially from the way evolution is described in this article. Why is epigenetics and multi-level selection given such little attention??? Is there a solution to this? I could write an entirely different article on evolution that would still be about evolution, but have a very different set of explanations relative to what is given herein. What to do?? I'm just going to leave it at this. I'm going to keep busy on other pages, but I feel that the current state of this article completely misses the point on what evolution is about as it avoids the disconnect between genotype to phenotype and where natural selection operates. Dawkins suggests it is all about jiggling of genes (building on George Williams ideas, who also wrote popularized evolution books), but those ideas were introduced in mainstream books - the peer-reviewed scientific literature takes a different position. I have great admiration for Dawkins, but he doesn't speak for the entire scientific discipline and to many he has fallen well off the mark.Thompsma (talk) 23:28, 15 December 2010 (UTC)

I gave up on the epigenetic contribution long ago, but you are welcome to try. This reminds me of the Altenberg 16 remarks and revisiting the Modern Synthesis. Science 11 July 2008: Vol. 321 no. 5886 pp. 196-197 .DOI: 10.1126/science.321.5886.196 •News Focus. EVOLUTION.EVOLUTION. Modernizing the Modern Synthesis.Elizabeth Pennisi. Regards GetAgrippa (talk) 04:14, 17 December 2010 (UTC)

I'm not really up for trying, because this page keeps evolving!! It is a huge struggle to get people on board, a little headway is made and then the article regresses. You could write an article on the evolution of wikipedia's evolution page.Thompsma (talk) 06:01, 17 December 2010 (UTC)

I'm surprised at the epigenetic resistance since even mention of methylcytosine as the fifth base made the cover of Science just a few issues back. The fact some epigenetic changes are heritable further fuel an evolutionary significance. I think there is plenty of publishable data to support it just isn't changes in genes but changes in gene regulation and networks that are often responsible for evolutionary change. GetAgrippa (talk) 15:45, 17 December 2010 (UTC)

My knowledge is limited to the NOVA documnetary "Ghost in Our Genes". So I remain humble. It seemed there were questions still unanswered over the duration of the effects of the environment on genetic expression due to methylation and/or modification of histones. Although the effects were trans-generational - the narration seemed that it was limited to three or so generations. If so, is such a short impact evolutionary? If you are aware of a document that addresses long-term effects to the epigenome as it relates to heritable adaptations shaping populations over-time; I would be very interested in reading it. If the impact is not a short-term anomaly; then perhaps I should do more in in my advanced classes as it relates to evolution. (Sigh) so hard to keep up ...I remember my principal chastising me for discussing DNA - since it was too cutting edge to have merit. Thank you.--JimmyButler (talk) 20:58, 17 December 2010 (UTC)

Vernalization in plants is mediated by epigenetic regulation of repressor genes, imprinted genes in mammals are heritable. Seems inevitable they would have some evolutionary outcome. Even if an individual is genotypically robust, poor nutrition during development can generate a weaker disease prone individual from epigenetic alterations which last through life. I guess you can argue the epigenetic influcence are outcomes of evolution-epigenetic regulation. But sex evolved and is also a process of evolution, and imprinted genes are sexually transmitted. Seems problematic because the epigenome can regulate the phenotype and so it begs the question is a species real. Reminds me of the eastern turkey in florida. I believe it was classified as a separate species, but later fouind to be the eastern species -just epigenetic alteration and darker plummage. The whole idea of natural selection would-should include epigenetic influences on a population as it would impact survival and the phenotype of individuals within the population through time. Regards GetAgrippa (talk) 23:08, 17 December 2010 (UTC)

Thompsma, I strongly encourage you to BE BOLD and make the edits you see justified. I agree with you in principle, and the key thing is you have reliable sources at hand to make the corrections and additions you propose. I hypothesize that the reason for the Dawkins bias has to do with the fact that most people who edit WP are not specialists and rely on the most popular popularizers, and Dawkins is pretty damn popular. I do not think anyone would accept removing his views from the article, but NPOV demands that we add other significant views and Simpson, Mayr, Haldane, Gould etc. are all quite sigificant. Fortunately, several people who watch this article are well-informed, have done serious research, or are actual specialists in the field and I believe that they will ensure that any significant view from a reliable source that you add, as long as you do not give it undue weight and DO give it appropriate context, will be preserved. Some editors have concerns that this article is groing too long, but I think your most important points can be covered concisely and as you say they merit at least equal weight to Dawkins. Please do not be so pessimistic! People may edit whatever you add for style, brevity, and if necessary more effective neutrality, but I believe many will value your contribution. Slrubenstein | Talk 00:37, 18 December 2010 (UTC)

Slrubenstein, I was already bold and see that this article in particular regresses back to its current state. At present this article is a hodge-podge of outdated evolutionary factoids and misses out on an informative synthesis. It is clear that the community on this article is not really willing to accept an update on evolution or improvements to the article that would give a better NPOV explanation of evolutionary theory. This article should not be featured in its current reductionist state and it is dreadful to see that it has been noted in the press for its purported quality. Dr. Kevin Padian, who fought for and represented evolution in the Kitzmiller v. Dover trial, recently wrote an article on why we need to teach macroevolution[8] and I think this advise should be headed.

If anyone wishes to take up this challenge I would suggest that the article start off by defining the relations among genotype, phenotype, and traits. Furthermore, the role of traits in evolution can be simplified by introducing the concept of Darwinian replicators vs. interactors. The replicator/interactor concept really helps to clarify why Dawkin's genetic reductionism is misguided. Organisms do not have traits that work in isolation and these traits are not dependent upon gene replication alone, they interact. What is a gene anyway? (I link to Brosius and Gould genomenclature[9], but Sewall Wright gave a much better discussion on what a gene is in his classical four part series Evolution and the Genetics of Populations[10] - see Chapter 3 'The Gene'). How can Dawkin's dissect the argument down to an element that really has no clear boundaries? The gene concept is an old debate and it is a metaphor, not really an operational unit as Dawkin's suggests. It is the interaction among traits (epigenetics) that is subjected to the environmental interface of euclidean spacetime, which is what makes life systems accountable and aptively malleable. I truly enjoy reading Dawkins, but then I read Gould, Eliot Sober, David Hull, Rupert Riedl and a whole fleet of publishing evolutionists who have managed in the peer-reviewed literature to successfully and repeatedly show why Richard Dawkins is mistaken on his primary focus of replicators. Dawkins recently came out of hiding into the peer-reviewed literature (in the Philosophy of Biology)[11] against macroevolution for the first time in years, but his ideas were quickly rejected by other scholars who published in the journal Evolution.[12] Dawkins makes some strong points, but he has clearly been rejected by his peers on this stance. Here is how Gould and Lloyd[13] stated it:

The logic of the theory of natural selection, as many evolutionary theorists and philosophers of science have recognized (4–12), assigns the status of causal agency in selection to interactors, defining them as individuals that:

• (i) Interact with the environment, broadly construed as all surrounding and influencing biotic and abiotic factors, in such a way that

• (ii) One or more of their traits imparts differential reproductive success through the interaction, so that

• (iii) Relatively more or less (compared with other individuals at their level) of their hereditary material (however packaged) passes to the next generation.Thompsma (talk) 22:36, 22 December 2010 (UTC)

Epigenetics: no-one doubts its huge importance in cell biology and developmental biology. Its significance (or not) in the mechanics of evolution is not clear at present. The fact that some epigenetic changes are heritable for a few generations does not prove that they are significant sources of evolutionary change. It may take ten or twenty years before we have a grasp of all the implications; we'll see what we see. Meantime, as an encyclopedia, our duty is to prefer the standard mainstream view, which is hard enough to do, given the limitations of space. Any statements on epigenetics would need to be gone over with a fine tooth-comb. Macdonald-ross (talk) 11:43, 24 December 2010 (UTC)

Thompsma is making to diferent points. One is that the article should be reorganized a particular way. He proposed this before, and there was an extensive discussion, and his proposals were rejected after thoughtful discussion. It is unfair of him to characterize this as some kind of regression - it shows a lack of respect for other editors who do not hsare his point of view. His other point is that the article does not incorporate the views of such as Sewell Wright, George Simpson, Conrad Hal Waddington, Lynn Margulis, Ernst Mayr, John Haldane, and Stephen J. Gould effectively. I think this is a fair point and wish we could have more discussion on diferent ways to accomplish this. Slrubenstein | Talk 13:01, 24 December 2010 (UTC)

The article is an updated and revised verson of the evolutionary synthesis, and as such it necessarily includes ideas from Wright, Mayr, Haldane and Simpson and many other important evolutionists. Of Margulis and Gould it can be said that the article includes those ideas which have gained general acceptance.
I note yet again that the length of the article does not permit indefinite extension; that we have 20 or 30 other pages on aspects of evolution (some of which might be better places to make changes); and that sweeping, hand-waving generalisations and claims to superior knowledge are not good uses of talk pages. Proposals need to be detailed and specific, and time must be allowed for others to comment on them. There may be good reasons for our supposed resistance to change. I, for one, am not convinced that large-scale changes would improve the article. Macdonald-ross (talk) 17:29, 24 December 2010 (UTC)

I don't mean any disrespect to the editors Slrubenstein, so please try not to spread offensive conjecture - I'm putting an honest effort to discuss these issues politely and do not want to get into a quarrel. This is not personal. I'm giving a serious academic effort here and providing some well cited materials to back up my claims. There is a great number of people who contribute to this article - so no single person can be singled out. I am 'volunteering' my time to give a critical appraisal of the article because it is lacking important details and giving a synthesized perspective on evolution that is inconsistent with a very large block of scientific literature (contemporary and historical). I have pointed out specific examples using cited scientific works that contest many of the statements in this article - notably parts dealing with epigenetics are severely lacking and simply infactual. Of course I fully understand that there is never going to be a consensus, nor should there be and this article cannot give every point about evolution. However, there is a very strong bias in this article against the holistic multi-level view of evolution that has survived, thrived, and been a very active agent of evolutionary thought since its beginning. The first sentence of this article - "Evolution (also known as biological, genetic or organic evolution) is the change in the inherited traits of a population of organisms through successive generations" sets the stage for the bias that follows. It is simplification of Dawkin's view on evolution, with the exception that it replaces 'gene' with 'trait', which is a 'slight' improvement. (However, as noted by Gould[14] "Dawkin's arguments against species selection are refreshingly clear about this distinction. Following his admission that species selection is, in principle, possible, he expresses skepticism that species selection may be important in explaining evolution...Dawkins may be revising his view, since he has now offered a species-level selection interpretation for an aggregate species-level trait (14).")

If evolution is just change in heritable traits of populations of organisms as this article claims, then I have to ask why the integrative field of eco-evo-devo is even around and making such scientific headway? Evolution also sees change in the inherited traits of a population of cells and this applies to species traits as well. The first sentence is a perfect example of the bookkeeping fallacy that says nothing about evolutionary causality and it continues "variants with particular traits become more, or less, common" - more bookkeeping! If evolution is just change in inherited traits in the commons of a population of organisms, then how is it that I have a notochord that has remained stable within our lineage for millions of years? Evolution is not just about change, it is also about the preservation of characters and Darwin discussed this at length. The expanded synthesis using multi-level selection provides some of the causal answers as to why certain character states are preserved and it also has much to reveal about the evolvability of life (e.g. [15] "The incorporation of processes that operate across hierarchical levels and a range of temporal and spatial scales has expanded and enriched our understanding of evolution."). This article could improve by incorporating some of the published perspectives that have been afforded by a great many evolutionary biologists who have been sidelined for their non-reductionistic stance.Thompsma (talk) 18:58, 24 December 2010 (UTC)

The problem I see is that outlined in the Science article. The modern synthesis really has focused on the gene and population genetics, modeling, and statistics (genotype). The recent (and exciting finds in epigenetics) offers an interface between the environment and the biological. Further the once junk DNA is now a treasure trove of regulatory elements. The face of genetics is changing and with that evolution biology will change too. The phenotype and reproductive isolation have been a defining characterstic of a species, although there are some twelve definitions of a species (roughly some ridiculous number). Understanding this new level of epigenetic control of the phenotype should prove interesting. Anyways I like Thompsma suggestion but I have to agree with some apprehension with the epigenetic as this area is still in development-the mulitlevel selection should be included without doubt. I like the work of Jablonka, etc. and this body of literature is growing so I have mixed feelings about how appropriate it is to add this. But wikipedia works by debate and consensus so there you go. We should be cautious of original research by using the literature to make our own arguments-I'm guilty of such at times. Hope everyone has a Happy New Year. GetAgrippa (talk) 21:37, 26 December 2010 (UTC)

Thanks GetAgrippa! I like Jablonka and Lamb's work as well, interesting stuff. I'm pleased that someone else is agreeing that multi-level/epigenetic selection is and has been a very active part of evolutionary research since its very beginnings (e.g., Clements and the supraorganismal concepts in ecology, Bateson's 1894 Homeosis[16], Richard Goldschmidt saltationism, Dobzhansky ideas in the 1940's [17], and even Medvedev's gene and character development paper in the 1930's [18]). There are thousands of evolutionary biologists who have been actively publishing on multi-level selection in the recent literature as well, including the collaborative work on niche construction[19], David Jablonski's research group and species level selection[20], David Sloan Wilson, E.O. Wilson, and even Douglas Futyama has been writing about macroevolution[21] - to name a few. You are correct that epigenetics in terms of genetic mapping, quantitative trait loci, and epigenomic studies mapping everything from siRNA regulators to large scale cellular physiology is still changing as the molecular studies pour in. However, there is a long history of epigenetics in evolutionary developmental biology that can be integrated effectively into this article on evolution and how it works. For example, the definition that is given for a trait: "Inherited traits are controlled by genes and the complete set of genes within an organism's genome is called its genotype" and natural selection: "Natural selection is the process by which genetic mutations that enhance reproduction become, and remain, more common in successive generations of a population" are both geared toward genes and say nothing about the epigenetic landscape or multi-level selection. The singular focus on genes does not help, it is a NPOV bias and it masks some of the most active areas of evolutionary discovery and understanding.Thompsma (talk) 23:50, 27 December 2010 (UTC)

Revision to the lead?

The first sentence in the lead is as follows: "Evolution (also known as biological, genetic or organic evolution) is the change in the inherited traits of a population of organisms through successive generations."

1. Do we really need the also known as list?? I vote that this list "(also known as biological, genetic or organic evolution)" be scrapped.
2. The sentence is partly correct about change, but it does not say anything about stability. It is important to remember that Darwin quibbled over the wording natural preservation vs. natural selection. Evolution is also about the preservation of traits. In order to understand this it is important to know that there are ultimate and proximate causes in evolution, "both have to be explained and interpreted for a complete understanding of the given phenomenon" (Mayr, 1961 - [22]) Ultimate are the historical explanations. Proximate answers often refer to the utility of traits. For example, I have a notochord and every other vertebrate has a notochord. Why is this trait preserved? The ultimate answer rests in the phylogenetic tree of life, possibly during the Cambrian period where it has been inherited by a unified lineage of decendants ever since its origin. The notochord is also burdened by other traits that have been built upon its scaffold. Since other traits are integrated and rely upon the notochord for development, they are preserved within the organism as a whole because all the parts must work together. Developmental biology describes how those parts (i.e., traits) functionally integrate into the organism, from genes, to populations of cells and the interaction among tissues. Many traits are adapted for their functional utilities, but some may be neutral byproducts (Spandrels in Gould's terminology, or even random drift). This is why I have suggested previously that the multi-level perspective is necessary - you cannot easily arrive at an ultimate and proximate understanding of evolution in the way that this article presently defines it.
3. Is there a way in the lead sentence to integrate the reasons for both change and preservation into the definition?
4. Evolution is a branch of science and the lead does not mention this at all. The scientific philosophy of evolution is too important of a detail to miss and it should be mentioned up front in the first paragraph.Thompsma (talk) 20:07, 3 January 2011 (UTC)

Evolution is a natural process. Evolutionary science is a branch of science.--Charles (talk) 21:12, 3 January 2011 (UTC)

Evolution, like ecology, is not just a process, but is a much broader description, presentation and understanding of the way that the natural world works according to scientific methods and philosophy.Thompsma (talk) 21:53, 3 January 2011 (UTC)

Ecology is the scientific study of ecosystems. It is not equivalent to evolution which is a process.--Charles (talk) 22:09, 3 January 2011 (UTC)

I didn't realize that there is already an article titled evolutionary biology, which kinda solves this problem, but it might still be important to mention something about evolution as a science. Ruse and Travis (2009) suggest that evolution refers to three interrelated ideas, 1) the 'fact of evolution', 2) the 'path of evolution', and 3) the 'theory of evolution'.[23] It is important to note that if you search under 'theory of evolution' you are redirected here, which means that something about evolution as science should be included. The interrelated ideas on the term evolution is partly responsible for the confusion we are encountering here. I may be quibbling too much over the lead sentence, but it seems a bit too wordy and a little too restricted to one level of the evolutionary hierarchy. I would suggest something simpler, such as 'The modern meaning of evolution refers generally to biological principals of descent with modification, a process that diversifies the tree of life.' This is more neutral in the way that it steers clear of the population level of change (as it is currently worded) vs. multi-level evolutionary change (as some evolutionary biologists see things) and it links evolution to the science via 'biological principals'.Thompsma (talk) 07:03, 4 January 2011 (UTC)

With all due respect, how could you not know? This article has multiple links to the Evolutionary biology article. Slrubenstein | Talk 15:01, 4 January 2011 (UTC)

This is an encyclopedia where people turn to explicitly find these finer details; this should be self explanatory. Evolutionary biology is a disaster and hardly worth its own link. Someone could spend their time improving upon the evolutionary biology article, but it would be difficult to really distinguish appropriate content for that page relative to this one. The boundaries should be clear. What is the difference between evolutionary biology and evolution? Courses and textbooks are titled 'Evolution' and contain information on 'Evolutionary biology' (for example, the following textbook[24] is titled 'Evolution', but refers to evolutionary biology throughout) - so in some sense these words mean and refer to the same thing. Both pages, evolution and evolutionary biology, say nothing about the scientific method as it applies in evolution. It is notable that the first chapter in Brian Hall's new evolution textbook[25] starts out by describing evolution as science in explicit detail. I realize this is not a textbook, but the scientific method in evolution is an important feature to overlook and there should be some mention (even brief) of the scientific method, experimentation and its application in evolution. With respect to the lead sentence and its emphasis on population level change I refer people to the University of California Museum of Paleontology and the National Center for Science Education 'Evolution 101' website[26] and their definition: "The definition Biological evolution, simply put, is descent with modification. This definition encompasses small-scale evolution (changes in gene frequency in a population from one generation to the next) and large-scale evolution (the descent of different species from a common ancestor over many generations). Evolution helps us to understand the history of life." They refer to and feel it important enough to make the same distinction that I make between small-scale evolution vs. large-scale evolution. An explicit distinction between micro- and macro- or multi-level evolution isn't necessary, but there are ways to use the wording such that it remains neutral on the distinction until it is made explicit deeper into the article. The current version emphasizes small-scale evolution and the trend persists throughout the article - referring back to the lack of epigenetics or multi-level selection that I raised under the heading of this thread.Thompsma (talk) 19:20, 4 January 2011 (UTC)

Constructal law?

A paragraph mentioning constructal theory was added and swiftly removed. Is this relevant here, and if so, to what degree? __ Just plain Bill (talk) 05:28, 3 January 2011 (UTC)

I have removed it for technical reasons (possible WP:COI - repeated addition of same information to several articles, by an editor related to the author of the theory, information sourced to primary sources by the author). I would be glad to learn the scientific value of this addition. Materialscientist (talk) 05:34, 3 January 2011 (UTC)

Thank you. __ Just plain Bill (talk) 06:00, 3 January 2011 (UTC)

The material should be removed until such time as independent, secondary sources are found to assert that constructal theory is of significance in an understanding of evolution. Johnuniq (talk) 06:25, 3 January 2011 (UTC)

I agree Johnuniq. Constructal law is interesting, but it does not belong in this article. A more appropriate home may be in the current research in evolutionary biology page for now.Thompsma (talk) 06:45, 3 January 2011 (UTC)

Species as statistical phenomena

The following sentence is weird: "Evolutionary biologists view species as statistical phenomena and not categories or types." I have never had a conversation with an evolutionary biologist who looked at me and said, you know I think of species as a statistical phenomena. Species are lineages, individuals, units, cohesive, real, and there is a long list of concepts. Moreover, if you read the citation to Kevin de Quiroz's paper - he says no such thing. The first paragraph to this section needs a re-write.Thompsma (talk) 20:24, 16 December 2010 (UTC)

Well, it certainly is how Darwin saw species. And also population geneticists. So perhaps the subject of the sentence should be changed. But the shift to statistics as a way of understanding phenomena is one of the hallmarks of the shift from natural philosophy or natural history to modern science, and the shift to looking at species as statstical phenomena rather than ideal types is the decisive break with Linneaus that made evolutionary theory possible. Do evolutionary biologists really think of species as "real?" An individual finch is real, sure, but what does it mean to say a species of finch is "real?" Doesn't this bring us back to the old "missing link" problem? Species are not discreet, clearly bounded things, if they were, speciation as we understand it, in terms of the modern synthesis, would not occur. Slrubenstein | Talk 13:56, 23 December 2010 (UTC)

I disagree that Darwin saw species as statistical phenomena - could you provide a reference? I've read everything Darwin wrote and I can't readily recall him writing about this explicitly. Mark Ereshefsky wrote an essay on Darwin's solution to the species problem[27] and he certainly does not frame it in statistical terms. Michaeal Ghiselin proposed a radical solution to the species problem many years ago[28] and this has resonated strongly in the philosophical and scientific literature. Some think of them as real, some do not - but this is the first time I've come across a statistical argument for a species concept - perhaps Joseph Felsenstein came up with something to that effect, but I've never seen it. A google search on "statistical species" "statistical species concept" pulls up nothing that seems relevant. Where did this idea come from and where is the citation? It seems hokey to me.Thompsma (talk) 18:17, 23 December 2010 (UTC)

I'll add the source. Slrubenstein | Talk 18:46, 23 December 2010 (UTC)

That's an obscure source and hardly worth mention. Why not stick to something that is more in line with the recognizable or familiar philosophy or science of evolutionary theory and the species problem? I'm still not convinced of the following sentence: "Darwinian theory involves a shift away from viewing species as ideal types to viewing them as statistical phenomena." This relies on a single obscure source whereas alternative ideas abound in the accessible peer-reviewed literature, none of which state that Darwin saw species as a statistical phenomenon. It is true that Darwin's cousin, Francis Galton, was a statistician and influenced his thinking, but this still does not mean that Darwin saw species as statistical phenomena. I'm calling this one out and I don't buy it. Stick with the obvious. There are pluralistic views on what constitutes a species. Some philosophers are monists, others are pluralists. There is a multitude of species concepts, the statistical species concept is not one I have heard of before, but it is an intriguing idea. Species are generally held to be individuals in the philosophical sense of the term, spatially temporally isolated with ontological development. Darwin saw species as open ended (although, this has been contested[29]), whereas modern philosophers place a cap on the species category as real individuals. "The distinction between species taxa and the species category is central to Darwin’s solution...Darwin thought the groups identified by competent naturalists could be real. His skepticism of the species category did not extend to taxa, and in particular those taxa called ‘species.’...So we have reached the same end point as Darwin: though we should doubt the existence of the species category, we should not doubt the existence of those taxa called ‘species’ by biologists." (Ereshefsky, 2009 - linked above) Thompsma (talk) 19:45, 23 December 2010 (UTC)

It is hardly an obscure source. Louis Menand is one of the most respected intellectual historians in the US today, and the book was very widely and well reviewed. In any event, the paragraph as a whole I think makes the point clearly enough. Slrubenstein | Talk 20:21, 23 December 2010 (UTC)

I should rephrase - perhaps it isn't an obscure citation, but it certainly is not the first place I would go looking to understand something about evolutionary biology. I've read extensively on this topic and have sat in philosophy courses with Marc Ereshefsky for several years studying and discussing the topic of Linnaeus and the biological species concept. I have never come across this idea. Moreover, I linked to Menand's book and did a search for statistical phenomena, statistical, and species as key words - from what I can read this is not what Menand is suggesting - he is saying that Darwin applied the statistical method to biology in a philosophical sense, but I cannot find any reference in my search that says Darwin proposed a statistical species concept or saw species as statistical phenomena. The Metaphysical Club is more of a literary work than a scientific or philosophical treatise. The paragraph is wrong, misleading, and uninformative about the scientific literature and current thinking on species categories and taxa - the backbone of systematic biology and phylogenetic methods. Actually, I would classify that citation as an obscure reference to evolutionary biology. The book won a Pulitzer, but not for its science or philosophical underpinnings of the species concept. Stick to the appropriate literature and get rid of the obscure reference to species as statistical phenomena - never heard of it and until you can provide a credible reference in journal of evolution or something of scientific equivalence, I'm going to remain skeptical of this.Sections on allopatric, peripatric, parapatric, & sympatric modes do read properly and I think I threw in the reference to Allan Templeton and the founder effect (Mayr's original idea - possibly Fisher if you go back further). However, the last paragraph on punctuated equilibrium (related to the founder effect) is not described very well and needs to be improved. Thompsma (talk) 20:56, 23 December 2010 (UTC)

I do not know why you would think it is about literature or liteary; as I said it is intellectual history and well-respected. Scientists are obviously important sources on science, but not the only ones; philosophy of science, sociology of science, and history of science are all valid too. This aticle has room for multiple points of view, not just your own. I am pretty confident this article represents other views. Slrubenstein | Talk 00:57, 24 December 2010 (UTC)

I'm not convinced that Menand's book says that Darwin viewed species as statistical phenomenon. Please provide a page number, because in my search I have not found where Menand says this. Second, I am not presenting my own opionion, I am presenting literature from peer-reviewed scientific sources and books I have read on this topic. It is true that there is room for books not published by scientists that would be perfectly acceptable to reference in here. Jonathan Weiner's book 'Beak of the Finch', for example, is a great resource. David Quaman's 'Song of the Dodo' would provide a great resource for ecology or biogeography. However, the issue of species and how Darwin viewed species is an extensively researched topic in the scientific literature. The scientific literature in any of the species concepts does not mention a statistical species concept. If Menand is presenting something entirely new and separate from what is being presented in the scientific literature, I think that this is the write place to introduce that idea. However, I am not convinced that Menand is doing this from the bits that I have searched and read.

There are logical reasons why species as a statistical phenomena would not work from a systematic point of view. For example, Templeton's species concept has a two part test. First a species is a monophyletic lineage. If true, then the second part of the tests for fixed traits (genetically exchangeable and/or ecologically interchangeable in his own words[30]). Species are lineages and certainly Darwin understood species in this way.

What is statistical about a lineage? To my mind a statistical species concept might apply by means of a test for trait variation among structured populations showing a significant deviation from a normal distribution (or some other distribution - binomial, poison, etc.), such as you might expect as you pass over a hybrid zone. Or perhaps it could be thought about in terms of genetic or morphological distances plotted into phylogenetic trees using maximum likelihood or Bayesian inference. Gene trees, however, are nested into species trees and these ideas where developed after Darwin's time. It is a convoluted argument to suggest that Darwin viewed species as a statistical phenomenon, because not once did he express his thought on species in this way and I highly doubt Menand even says this. It is best to use a simpler piece of literature that directly addresses the species problem. Marc Ereshefsky, David Hull, Ernst Mayr, Kevin de Quiroz, Joel Cracraft, John Avise, or Craig Moritz is a short list of some authors who have written extensive papers and books on the species concepts. They would be appropriate people to consult. Why would anywone ignore these people and cite a book that doesn't address the species issue directly?Thompsma (talk) 06:00, 24 December 2010 (UTC)

I am content with the speciation section as it now is, and you, Sir, should stop using this as your personal blog page. Macdonald-ross (talk) 11:21, 24 December 2010 (UTC)

There's that resistance again and this is why evolution in wikipedia will never serve as a reliable source. Macdonald-ross - I am discussing research matters pertaining to the validity of sections in this article in earnest, so spare me the lesson. I'm pleased that you are content with spreading misinformation, but there are others in the world who care about these matters and would like this page to serve as a reliable source. I've made significant contributions to wikipedia - I wrote the entire ecology page on my volunteer time, so I am not a blogger - I am a dedicated researcher. Evolution is always a struggle to work with because there is a huge mass of resistance to improving this article - your comment is a perfect example. Wikipedia evolution is a serious problem.Thompsma (talk) 16:52, 24 December 2010 (UTC)

Species are not statistical phenomena and have never been viewed as such. It is nonsense. Provide the reference or this idea needs to perish.Thompsma (talk) 19:09, 24 December 2010 (UTC)

Under 'Speciation', I would not have chosen "statistical phenomena" myself, partly because the term 'statistical' is ambiguous. I would instead have preferred the word "populations", and I think it would be possible to find two or three hundred references to support this usage (I will provide a few!). I am not against constructive changes; I am against the sweeping nature of your criticisms, which I do not consider to be justified. Macdonald-ross (talk) 15:28, 25 December 2010 (UTC)

This change is now made, with ref. Macdonald-ross (talk) 04:05, 26 December 2010 (UTC)

Population is a misleading idea, although I won't delete it. Populations are interacting groups of organisms. This is not the same thing as a species or two reasons. First, ring species consist of netwoks of interbreeding populations, but the two populations most distant from one another are diferent species. Second, you can find two populations of the same species that are separate and not interacting. Yeah, evolutionary theory suggests that these two populations may eventually evolve into diferent species, but at a given time you can still have two separate populations that ae one species. So there has to be a way to define the specis other than as population. Biologists today understand that mmbes o the same spcies will not be identical, nor should they be; rather, there are a multitude of variations among members of a species but statistically these fariations plot around a central point. Thompsma seems not to understand this basic claim of evolutionary theory: that on does not identify a species through its corespondence to an ideal type, because in the Darwinian modle variation from the type is good and ncessary - to make this claim is to make a great leap forward intellectually. Species appear to exist because one can plot all the variations and they will cluster around a point or along an axis but over time where this cluster is may shift. This was a headache for old-fashipned linnean natural scientiss but not for anyone who understands species statistically. I m surprised to see this reacion against statistics in biology - without statistics science is set back a couple of hundred years. Slrubenstein | Talk 12:21, 26 December 2010 (UTC)

I have no idea what you are saying Slrubenstein - no offense, but the sentence where you say I have no understanding is quite a leap since I have not said anything of the sort. I have no problem with someone publishing on the idea of species as a statistical phenomena - the problem I have with the concept is that I have not seen a publication on the idea. I have worked as a geneticist for the past six years and help graduate students build phylogenetic trees on a regular basis where we employ statistical techniques and I have published a few papers using phylogenetic statistical methods. So I have a great appreciation for statistical methods in systematics. However, I also have a great appreciation for the morphological and developmental sciences as I worked in a paleontology lab for five years. Much of what you are expressing about statistical species and how speciation works is philosophically and historically empty. There is a long history of thought in this area and from what I can tell - you are making things up rather than drawing upon well researched and reviewed literature. Willi Hennig would be a good place for you to start [31].

In response to Macdonald-ross and his critique against my sweeping reform. I am not suggesting sweeping reform of this article, but corrections where they are necessary. There are many mistakes and misleading paragraphs in this article that steers the reader away from evolution as it has generally been represented in the literature. Some sections of the article are fine, but the lead and emphasis on genetic evolution bookkeeping (vs. epigenetic multi-level) is a serious problem.Thompsma (talk) 18:14, 26 December 2010 (UTC)

Adding a citation to Ernst Mayr's book "What evolution is" under the statistical species notion that is being presented in this article does not make it cited and correct. I have read Mayr's book and have a copy sitting here on my lap. I re-read chapter 8 'The units of diversity: Species' where Mayr addresses the species problem. He talk about species taxa vs. concept. There is no mention of "viewing them as populations, definied statistically, by the degree of coocurence of multiple traits" as it so claims in this article. There is no reference anywhere that defines species statistically. The sentence is now more incorrect because it states that Mayr is making the same claim, when this is false. Please post reliable and truthful information that is consistent with the literature and fix this error.Thompsma (talk) 23:12, 27 December 2010 (UTC)

The sentence says a couple of things. The mayr citation suppots one thing; th Menand citation supports another thing. Perhaps you personally have not read the published account of this idea, that Darwin's key insight was to think of species statistically rather than as ideal types ... but the published account exists, and I provided a citation. The threshold or inclusion in an article is a reliable source, not "sources Thompsa has read." I have posted reliable information (wikipedia is not about truth, I do not know why you bring up this red herring), indeed I posted a source, and I posted it quite some tim ago, lon before you raised your concern here - so your babbling about errors is really out of place. Slrubenstein | Talk 08:40, 28 December 2010 (UTC)

Slrubenstein, I've asked you politely to refrain from derogatory statements and to keep the discussion on track. I am a qualified biologist with three post-secondary degrees, one is a MSc in Zoology from the University of Calgary. I am not rambling - I am informed and knowlegeable in my field. Whatever your issue is with me, get over it and grow up - it is a waste of time and I'm trying to help. Once again, Menand does not say anything about statistical phenomenon that I can see - I've asked multiple times for you to provide a page reference. Dave's citation below helps to explain the train of thought, but still the article does not capture the correct explanation.18:28, 29 December 2010 (UTC)

Why ask multiple times for a page reference, when the citation provided includes page numbers? Of course, you can also try the index. But I would think anyone who has read the book would get the point quite clearly. Slrubenstein | Talk 18:38, 29 December 2010 (UTC)

I think Slrubenstein is just reacting from your first posts here. Such comments as: "Your comments are very typical of the PhD ego inflation hypothesis. My reason for being persistent is because I have a feeling that what is taking place here is a cultural phenomenon and an American bias. I don't know what country you are from - but in Canada there is a noticeable trend trend in American textbooks on evolution. The Kansas schoolboard and the other ID movement has created a fear and a defensive approach in presenting on the topic of evolution in the US. I suspect that the reason why there is an opposition to including a paragraph on cultural evolution." Then there was this tirade:"The most amazing part to this discussion is that I have been combating a culturally predictable behaviour: "A subset of chimpanzees that discovered the alternative method nevertheless went on to match the predominant approach of their companions, showing a conformity bias that is regarded as a hallmark of human culture."108 I would hope that people in here would have the cognitive aptitude to escape this conformity bias and learn the concepts rather than poke insults at me. Guppies exhibit this same type of behavior - put a female in a tank she will go for a colorful male, but put a fake female near a drab male and she will compete for the drab male. People in here are conforming and gravitating toward the drab cultural evolution hypothesis. Those who stooped to low brow insults now have some apologizing to do and should concede that cultural evolution is explained by biological evolution using multi-level selection or extended evolutionary theory.[109] This was even called mental masturbation - but what an uphill battle I have had to fight in this playground! I've tried to overcome this bias time and time again - but people always revert back to the same old gene reductionist arguments, which are not helpful nor are they representative of what evolution is about." You have to admit you sound like a egomaniacal lunatic with comments like that. I think frustration initiated these responses so I'm not criticizing nor laying judgment. I've made similar comments and been just as frustrated-that is why I only comment and refuse to write in this article. But we all have be patient and everybody needs to be civil and polite. Regards GetAgrippa (talk) 16:10, 30 December 2010 (UTC)

GetAgrippa those comments are taken out of context and were made long ago in a heated debate with another person(s). I stand by my comments with respect to the cultural influence of the ID movement in the US (and elsewhere). This has been noted by other scholars who have seen a shift in US textbooks on evolution where there are chapters devoted to ID and a shifting emphasis on how evolution is taught. This does not mean that every US evolutionary text is tainted, but it is important to realize that pressure from the ID movement into schools and education is a factor worth consideration. Moreover, in this wikipedia world where there is a community of people writing an article - I believe it is important to consider how our evolutionary collective behaviour vs. independent authorship might influence the decision process when there is evidence for conformity in other social settings. In the end I got a barnstar for my efforts during that debate because the article was revised and improved, so your critique is unwarranted. I would appreciate that you refrain from trying to maliciously flame the fire and stick to the discussion at hand. Please do not cherry pick quotes from historical discussions. When taken out of context your synopsis gives the wrong impression of what was going on in those discussions, plus people make mistakes. I don't believe that you believe in your own message of keeping things polite after you just dropped an insult bomb followed by a self serving message of keeping it civil!! Better to just drop it. We work best when everyone talks about the topic of evolution and how it should be threaded into the article Thompsma (talk) 19:06, 3 January 2011 (UTC)

Darwin's thinking

• Bowler, Peter J. (2003). Evolution: the history of an idea. Berkeley: University of California Press. pp. 145–146. ISBN 0-520-23693-9. states "A key factor in Darwin's innovation was what Mayr (1964, 1982) calls 'population thinking' – the transition from seeing species as based on an ideal type to seeing it as a population of distinct individuals. .... Population thinking also represents a transition in 19th century scientific thought noted by John Theodore Merz (1896–1903): the emergence of the statistical mode of explanation designed to cover changes so complex that the behavior of their individual components cannot be predicted. It is possible to see the rise of Darwinism as the creation of a statistical mode of explanation as opposed to the old Newtonian view of causation based on law (Depew and Weber 1995). We must balance the claim for a direct input from Darwin's social environment against the evidence for a growing awareness that, for science to tackle certain kinds of questions, a new type of explanation based on statistically modeled changes was needed." On p. 147, "Darwin wanted to create a theory based on natural law in the Newtonian tradition, but by the very nature of the problems he addressed he was forced to transform this program by introducing statistical and historical elements into his explanations." . . . dave souza, talk 23:55, 27 December 2010 (UTC)

Thanks Dave, I have taken the liberty of adding this source. Slrubenstein | Talk 08:40, 28 December 2010 (UTC)

This is better, but still the evolution article does not say the same thing that the Bowler citation says and it is filled with spelling errors. Bowler states that Darwin introduced 'statistical and historical elements', not statistical in isolation as the article alludes. The article states that Darwinian species are a "a shift away from viewing species as ideal types, definied (sic) by the presence of a particular trait, to viewing them as populations, definied (sic) statistically, by the degree of coocurence (sic) of multiple traits."

I suggest the following: "...a shift away from viewing species as static ideal types, defined by the presence of a particular trait, to viewing them as populations with a history that requires more of a statistical approach for the analysis of multiple variable traits."

It is still a little awkward, because Darwin didn't apply statistical methods and Bowler gets this message accross by explaining in greater detail the shift from Newtonian causation and law. The following sentence in this section still remains incorrect: "evolving lineage that forms a single gene pool." The next sentence about fuzzy boundaries based on morphological traits is also weak and misleasding. Phylogeographically we know that multiple gene pools absolutely exists within a single species. I see where this is going in terms of Mayr's biological species, but a species clearly does not form a single gene pool - see metapopulation.Thompsma (talk) 18:17, 29 December 2010 (UTC)

No objection to the changed wording, have made the more obvious spelling and grammatical corrections. There's an underlying issue in that the article lead doesn't even seem to link to species, yet the Species problem is a central aspect of the concept of evolution. Not so sure that Darwin didn't apply statistical methods, in that his word and experiments clearly involved statistic, but he may not have used that as a definition of the population forming a species – his concern was to show that the boundaries between species are fluid. However, we use the phrase "Darwinian theory" which can mean anything from Darwin's own views to the Modern evolutionary synthesis and the views of Dawkins. . . dave souza, talk 23:49, 29 December 2010 (UTC)

It might be semantics by what we mean when we say statistics. It is certainly true that Darwin was familiar with statistics and discussed this with Galton (see, [32]: “Darwin was a leader in a subfield of statistics called experimental design,” he says. “He knew how to design a good experiment, but what to do with the numbers was something else.”). He also referred to the first ecological experiment [33], which certainly had a statistical design[34]. I agree with everything else you have written and thanks for throwing your support on the new wording. I'll go ahead and make the changes.Thompsma (talk) 00:28, 30 December 2010 (UTC)

This is heading in the right direction. Let's not forget to distinguish between statistical methods, and the entire paradigm shift initiated by the rise of statistics. Today, statistics dominates the life and physical sciences to such an extent that their use is unquestioned, and students study statistics principally as a method. But in the late 1700s to mid 1800s, statistics was not solely applying specific formulae to the analysis of particular problems. It represented an entire shift in how people thought. In physics, this was a shift from thinking of the universe in terms of Newtonian mechanics (the watchmaker's model). Before Maxwell's distribution, which could be expresse dmathematically, was Bernouli's insight that gases could be thought of as collections of individual molecules moving in diferent directions. We take this for granted today, but in the late 18th century this was really radical. Similarly, you do not need to understand the Dirac Equation or Feynman's mathematical formulae to understand the great leap prom imagining electrons as little planets in little solar systems to imagining them as probabilistic distributions among quantum states. My point is that Darwin need not have used statistics as a method (certainly not the statistics population geneticists use today) to grasp the significance of viewing species as a collection of indivuals which, if large enough, can be seen to have traits distributed in ways that were becoming increaingly familiar to scientists. The importance of this shift in thinking is significant: even today a museum or individual collector might wish to place in their collection the "perfect" specimin of D. plexippus. This is certainly how Linnaeus and his followers worked. Darwin's insight was that th perfect specimin may not be so perfect after all; that what we today call statistical outliers (and I would say this is a matter of semantics - it does not matter whether Darwin used this language, what is important is he used this idea) might be more important to the propagation of the population; that as the environment changed former outliers could become th new statistical norm and even the progenitor of a new species that would replace D. plexippus after it becomes extinct. This is what it mans to think species statistically rather than as ideal types. I think Darwin understood that most people would always use the word "species" to refer to an ideal; his point is that what was important (not just to him personally but to understanding natural history) was not the ideal but the variation away from the ideal. Darwin understood that there had to be some mechanism to produce variation - that variation, even if it often lead to the death of an individual, was on the whole necessary for life - long before we identified the most important mechanisms of variation. Maybe we had to wait for the discovery of genes before we could develop the Hardy Weinberg law and many other statistical tools now commonly used. But the fact remains that just as Bernouli anticipated Maxwell and Boltzman, Darwin anticipated the dominance of statistical methods today - not because he necessarily used statistical methods but because his theory conceived of species in statistical rather than ideal terms. Slrubenstein | Talk 13:10, 30 December 2010 (UTC)

This is raising several very interesting questions, even if it's perhaps getting rather detailed for the main topic. In discussing how to define species, Darwin on p. 52 of OtOOS of 1859 said that he looked "at the term species, as one arbitrarily given for the sake of convenience to a set of individuals closely resembling each other, and that it does not essentially differ from the term variety". In subsequent pages he describes how "Guided by theoretical considerations, I thought that some interesting results might be obtained in regard to the nature and relations of the species which vary most, by tabulating all the varieties in several well-worked floras. At first this seemed a simple task; but Mr. H. C. Watson, to whom I am much indebted for valuable advice and assistance on this subject, soon convinced me that there were many difficulties, as did subsequently Dr. Hooker, even in stronger terms. I shall reserve for my future work the discussion of these difficulties, and the tables themselves of the proportional numbers of the varying species. Dr. Hooker permits me to add, that after having carefully read my manuscript, and examined the tables, he thinks that the following statements are fairly well established. The whole subject, however, treated as it necessarily here is with much brevity, is rather perplexing". He then outlines his statements up to p. 58. A similar section is featured in the 1872 6th edition, p. 42 onwards, but I don't know if his tables were published or given statistical analysis in the modern sense. . dave souza, talk 14:01, 30 December 2010 (UTC)

Thanks for again providing important input. I certainly do not think that this issue should be discussed at length in the article (maybe in the Species aticle and in the Charles Darwin article) - I am satisfied with the current amount of attention it is given (one sentence?), and wouldn't complain if someone could improve on the wording. I think in the above quotes, the key words are "that varied most" - viewing this as a good rather than bad think marks a real break from mainstream 18th century natural history. In any case, my opinion doesn't matter - we have a verifiable and reliable source making the claim. Slrubenstein | Talk 19:36, 30 December 2010 (UTC)

Yes...these are all interesting discussion points and I'm glad that we found common ground. I'm happy with the wording as it currently stands and think that the discussion details are going off the main topic. The point about statistical species was confusing with the original wording, but the current revisions and the Bowler, Peter J. citation that Dave souza added certainly helped to establish where this was going.Thompsma (talk) 21:21, 4 January 2011 (UTC)

Single gene pool

The following sentence: "Instead, a species is now defined as a separately evolving lineage that forms a single gene pool", needs to be revised because it is wrong. There are multiple gene pools within a species. I stated previously that it might be better to suggest that a species is a monophyletic lineage, but even this has its problems (see [35]). It would be better to make the distinction between a species concept versus a species taxon. A species taxon is the base or operational unit in systematics & taxonomy that is qualified by an accepted concept. A species concept serves to explain the biological reasons or mechanisms behind speciation.Thompsma (talk) 00:46, 30 December 2010 (UTC)

I see no logical conflict between a population forming one gene pool, and also having multiple gene pools within it?--Andrew Lancaster (talk) 08:45, 30 December 2010 (UTC)

I think you could say that a species is actually or potentially contributing to the same gene pool or sub-sets thereof. However, the sentence in this article is stating that a species 'is defined' by a single gene pool, which is technically incorrect. Species are defined by their history and the phylogeographic variation oftentimes forming multiple gene pools, races, demes, and patterns of reproductive isolation consistent with migrational ecology. There may be examples of highly endemic or rare species that form a single gene pool, but this would be the exception and not the rule. I understand what you are suggesting by the nested concept, but the sentence is making such a strong statement that I think we could do better.Thompsma (talk) 18:12, 30 December 2010 (UTC)

But wouldn't you say the human genome contains the human gene pool?? Ethnicities and populations or founder effects just display variants of the gene pool. Like Himalyan populations containing more oxygen sensing genes, etc. A species displays a gene pool of total genes but demes and populations (subsets) may display multiple gene pool variants from that gene pool. Further these changes may proceed to split and make a new species. I do think it needs to be rephrased. GetAgrippa (talk) 18:50, 30 December 2010 (UTC)

Published evidence that there are multiple concepts of how to define species is on the way to me in the post, so if her majesty's mail obliges I should be able to comment more on this in the next week or so. As a complete non-expert, my reading of Dawkins's The Ancestor's Tale p. 350 is that most biologists define speciation as occurring when populations of one species that have been isolated in some way no longer interbreed when reunited under natural conditions. This raises a number of questions and possible exceptions, such as asexual reproduction. His example also introduces the question of whether Pundamilia nyererei should be considered a different species to Pundamilia pundamilia, when their reproductive isolation is a result of sexual selection and is dependent on clear water: if their habitat changes and they interbreed, have they become the same species? Seehausen has evidently continued with research on these issues,[36] perhaps someone with more knowledge could expand these articles to mention the research. . . dave souza, talk 19:30, 30 December 2010 (UTC)

Thompsma, Dave is right that there are different definitions of what a species is, but the tendency is to define it in some way which is going to effectively mean that a species has a specific gene pool. Perhaps what you are saying is that not all distinct gene pools get to be called a species, and that is also true. I guess you could say that people tend to think of a species as the lowest level clade with a truly distinct gene pool? This still leaves a grey area, but I do not think this grey area can be removed given that species really do merge into each other and/or split gradually.--Andrew Lancaster (talk) 00:13, 31 December 2010 (UTC)

Species is simply not a well-defined concept, and the article should not imply that it is. I'm not sure what purpose there is in distinguishing between the species "concept" and species "taxon", since the latter is merely the codification of the former. Taxon is based on whatever we define 'species' to be, and as 'species' changes, so does taxon, as we saw famously with D. melanogaster earlier this year.

For sexually reproducing organisms, the biological species concept is the accepted champion, which is based on reproductive isolation that is the product of phenotype. This is not exactly identical to having a single gene pool (since that might be a result of mere happenstance, and subsequently corrected), and it's not exactly well-defined what "isolation" actually is. Unfortunately, the species article seems to have bowdlerized a clear statement of this concept in favor of a litany of species concepts.

When you get right down to it, this is pretty much an impossibility; we're trying to find a neat definition for the operation of life, which neglected to consult us before kludging together its assemblage of forms. The article would do best to give the simplest definition (the BSC), state that it's a compromise, point out difficulties with non-sexual organisms, link to species, and move on. Graft | talk 02:07, 31 December 2010 (UTC)

BTW, Speciation by Jerry Coyne and Allen Orr was my preferred reading on this subject. Graft | talk 02:16, 31 December 2010 (UTC)

My concern goes in two directions. First, there are gene pools within a species. Second, there can be genetic exchange among species:

"The classic illustration is American oaks (see Van Valen 1976). Various species of oaks appear to have coexisted in the same areas for millions of years while exchanging significant amounts of genetic material through hybridization." (p. 8, Dupre, J. 1999. On the impossibility of a monistic account of species. In R. A. Wilson, Species: New Interdisciplinary Essays. Massachusetts Institute of Technology.)

I'm not suggesting that we define a species or to give a list of every species concept. What I am saying is that the current wording is giving a definition and that definition is incorrect. Instead of giving a definition, the article could clarify what a species taxon is and what a species concept is. I think the BSConcept would be an important example to introduce with a link to the species problem or species concepts page following. The BSC is not a single gene pool, Mayr is very specific in his wording of a BSC - "Groups of potentially or actually interbreeding natural populations that are reproductively isolated from other such groups." - this is not necessarily a single gene pool.Thompsma (talk) 18:17, 31 December 2010 (UTC)

The dear old GPO has rather excelled itself, delivering the book by Wilkins within two days of my online order, and at first glance I note that Coyne and Orr's revised BSC makes concessions to some criticisms and defends against others. This "limited BSC" accepts Mayr's BSC with qualifications that could be summarised as "species are groups of mostly interbreeding natural populations that are mostly reproductively isolated from other such groups." That does seem to be the generally accepted approach, and Graft's proposal looks wise; a concise indication of the difficulties or alternative approaches is the most that belongs on this page and the detail should be worked out in the species article. In the historical context it may be possible to concisely clarify that Darwin viewed the difficulty of definition as evidence for evolution in which there is constant variation, and varieties are incipient species. . . dave souza, talk 23:01, 31 December 2010 (UTC)

Whichever way we decide to move forward, I hope that we can all agree that the existing wording of a 'single gene pool' needs to be revised. I like the soft BSC Dave. It is similar to Kevin de Queiroz's general lineage concept and his attempt to find a solution to the species problem. I also think it would be helpful to say that a species is defined as an operational taxonomic unit for the practical purpose of finding its position in the Linnean taxonomic hierachy or biological classification, where professional taxonomists and systematicists study and analyze the morphological or genetic characters from different lineages and use parsimonious methods (e.g., cladistics) to infer the evolutionary relations and explain the pattern of history. Second, a species is also defined according to the nature of its biology by scientific experts who choose a species concept that best explains the observations of that lineage and best identifies the critical natural forces that are responsible for the origins of diversity that is evolving in that unique branch of life. There exists a range of species concepts (more than twenty) that may impact the evolutionary placement of the species in its phylogenetic context. For example, some species concepts apply more readily toward sexually reproducing organisms and some lend themselves better toward asexual organisms. One or two examples of species concepts would probably suffice followed by a link to species problem or species concept. Is everyone in agreement that this kind of approach (with simplified wording) would be an improvement?Thompsma (talk) 04:21, 3 January 2011 (UTC)

Suggested revision to sentence/paragraph on single gene pool

To improve upon the single gene pool error, here is a draft of what I propose for the first paragraph on the section on speciation adding the hope that others could assist in breaking this down with edits/comments:

Species are defined in two ways, taxonomically and categorically. Species are partitioned taxonmically into operational units for practical applications in systematics. Systematicists study and analyze the morphological or genetic characters from different lineages and use parsimonious methods, such as cladistics or other statistical means to locate the position of the taxon in the Linnean taxonomic hierachy or biological classification. These methods create evolutionary trees that are used to infer, illustrate, or explain evolutionary relations, historical patterns, and phylogenetic transitions. "Systematics is one of the oldest scientific disciplines and, from its beginning, one of its central concepts has been the concept of species. Systematics can be characterized generally as the branch of science devoted to the study of the different kinds of organisms (biological diversity, in contemporary terms), and the term 'species' is Latin for 'kind.'" When a new species is discovered a type specimen and holotype specimens are usually deposited into a recognized or accredited academic institution, such as a museum, that serves as a taxonomic reference point.

Species are also defined categorically by critical natural forces that best explain the evolutionary mechanisms that are responsible for the crossing of the speciation threshold, from one species into two. In this context, the exact definition of a "species" is still controversial, particularly in prokaryotes, and this is called the species problem. Darwinian theory involves a shift away from viewing species as static ideal types, defined by the presence of a particular trait, to viewing them as populations with a history that requires more of a statistical approach for the analysis of multiple variable traits. There is much diversity in life and varied biological reasons for speciation, which has resulted in more than twenty different kinds of species concepts to facilitate the diverse modes, mechanisms, and evolutionary processes. The concept that is used is a pragmatic choice that depends on the particularities of the species concerned. For example, some species concepts may apply more readily toward sexually reproducing organisms and some lend themselves better toward asexual organisms. The various concepts, however, can be placed into one of three general philosophical approaches: 1) the interbreeding, 2) the ecological, and 3) the phylogenetic. The biological species concept (BSC) is a classic example of the interbreeding approach. Introduced by Ernst Mayr in 1942, the BSC states that "species are groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other such groups". Despite its wide and long-term use, the BSC like others is not without controversy. Some researchers have attempted a unifying monistic definition of species, while others adopt a pluralistic approach and suggest that there may be a variety of ways to logically interpret what a species is.Thompsma (talk) 20:55, 4 January 2011 (UTC)

If nobody has any opposition to these paragraphs, I would like to go ahead and insert them into the start of the section on speciation. I will spend a bit of time ensuring that the citations are in proper form. I was hoping for a bit of discussion and possibly some editorial feedback before I make a move on this. Thanks.Thompsma (talk) 06:12, 7 January 2011 (UTC)

Main source of variation

The article states that "The main source of variation is mutation, which introduces genetic changes." and " Another source of variation is genetic recombination ...". Is this correct?

What is the main source of variation between siblings? That is, why aren't offspring of the same parents just as identical as are identical twins? I know that identical twins come from one fertilized egg, while other siblings come from distinct fertilized eggs, but why are those eggs different? What is the main source of variation between two fertilized eggs from the same couple? Whatever is the answer to that question, isn't that the main source of variation in the population too? That's not mutation, is it? --Unflappable (talk) 02:37, 31 December 2010 (UTC)

Please remember the context. Sexual reproduction certainly mixes up the genetic material in a population, and does lead to variation among individuals in sexually reproducing species (remember too that most species do not reproduce sexually). But why do two individuals in a speciesd (genitor and genetrix) have different genes in the first place? Mutation. Slrubenstein | Talk 10:37, 31 December 2010 (UTC)

The article should not make the claim that the main source of variation is mutation - how can this be backed up?? It could be worded better by just stating that one source of varation is mutation. There are other sources of variation that stem from the complexity and chaos of life.Thompsma (talk) 20:14, 3 January 2011 (UTC)

This is a subtle point, and I am not confident the two of you are yet understanding each other, so be careful that whatever gets done to the article will be understood by others. @SLR, yes all genetic variants when we look at one point on one chromosome are from a mutation, but there are also variations caused by the way DNA gets recombined. In other words, two variants which already existed become linked in a new way (just by recombination, not mutation) creating a new variant.--Andrew Lancaster (talk) 09:10, 4 January 2011 (UTC)

@Thomps, Well, the article already gives equal attntion to drift as to mutation. Slrubenstein | Talk 14:58, 4 January 2011 (UTC)

@Slrubenstein there are other sources of variation beyond genetic variation (i.e., drift v. mutation) that you are missing here - most notably, developmental and/or ecological levels of variability (for example, [37],[38],[39]). Simply remove the reference to the 'main source' and just say it is one source. This claim cannot be quantified and it is in all likelihood false.Thompsma (talk) 21:04, 4 January 2011 (UTC)

@Thompsma. I am not sure how you can in any simple way distinguish mutation and drift. Drift describes a dynamic of certain mutations (in the sense of mutational variants) building up in a population. I am not saying it is impossible to somehow make a distinction between two different sources of variations, but I am not sure trying to contrast with the word mutation as a general term works in any clear way? Hope this makes sense. Or maybe this helps: I think you are using the word mutation in a specific way, and Slrubenstein in a more general and abstract way.--Andrew Lancaster (talk) 11:36, 6 January 2011 (UTC)

A DNA mutation is a base substitution, gene duplication, or crossing over on a chromosomal level. This differs from molecular drift, which is population level sifting and sorting of those mutations among individuals, some that become fixed others that go extinct. However, this is about variability - not mutation. You can have genetic variation, variation within and among populations, developmental variation, and even variability within and among species. These other levels of variation may have nothing to do with genetic mutation, they operate on an epigenetic level with environmental induction factors coming into play.Thompsma (talk) 19:34, 6 January 2011 (UTC)

Yes, I understand the complicated and subtle point, but the other way someone may be drawn to think of it is that all variations resulted from a mutation at some point. You may retort that this is not a useful way of looking at because some of those mutations might have happened before the species being discussed distinct, but my main point is that the distinction you are making is non obvious and would need a digression. If you write in such a way that the distinction between mutation and other sources of variation is obvious I think it will actually lead some readers to a wrong understanding.--Andrew Lancaster (talk) 20:28, 6 January 2011 (UTC)

Hi Andrew, I'm not entirely certain that I understand the meaning of your post. The main concern I have is captured in your sentence "that all variations resulted from a mutation at some point", which is the mistake. It is false to suggest that all variation results from mutation at some point. Genetic induction networks, for example, can result in a very different end product (i.e., variability) relative to the concentration of protein induction factors (for example), where no mutation is necessary (e.g., [40]). There is a very simple solution to this problem as I have stated - remove the word from the phrase that states that the 'main' source of variation is mutation, which is false. This does not require a lengthy digression, but as I suggested previously - it would be helpful for this article to give some honest detail on epigenetic evolution, because this is where the article suffers most. I also disagree that it is a subtle point, because Darwin and many others have labored on the notion of variability in evolution. It is a central concept toward understanding core evolutionary principals.Thompsma (talk) 21:01, 6 January 2011 (UTC)

I'll add a quote from Molenaar et al. (1993) [41] that might help with the understanding of this problem:

"Sewall Wright distinguishes three types of factors involved in the variation of fur coloration in guinea pigs: genetical, common environmental, and developmental. The latter type of factor is represented by D in the path diagram concerned and is suppossed to be associated with developmental irregularity. The results reported by Wright indicate that more than 91% of the total variation of fur coloration in an inbred line of guinea pigs is accounted for by D. Hence it appears that in this case epigenetical processes constitute a major source of phenotypic variation."

In a multi-level world there are even more opportunities for variation, such as that identified through John Thompson's geographic mosaic and coevolutionary concept (e.g., [42], [43]).Thompsma (talk) 21:44, 6 January 2011 (UTC)

I went ahead and made the change and the sentence now reads "One source of variation...". I have provided sufficient peer-reviewed reference material to refute the claim and justify this action.Thompsma (talk) 06:16, 7 January 2011 (UTC)

OK, maybe we are talking past each other. The source you now cite is indeed talking about variations which are not genetic and therefore not involved in speciation or evolution. An example might be number of football injuries that men have. A variation as to be heritable to be relevant to evolution. I should have looked at the text you were discussing more closely instead of the discussion here. It seems to me that the distinction being made in the current text between mutation and recombination will not be obvious to most readers. Is a novel recombination not a mutation? Secondly, many of the problems here could possibly be fixed simply by saying "heritable variations" instead of variations? --Andrew Lancaster (talk) 07:15, 7 January 2011 (UTC)

Andrew...Sorry but you are incorrect on several accounts. There is heritability above the gene and these variables are relevant to both speciation and evolution. I'll just post a few references from peer reviewed evolutionary journals with free pdf accesability that will explain these principals and mechanisms. Please review the following: [44], [45], [46], [47]. That includes four references that talk about heritability and selection principals operating above the gene (i.e., multi-level selection). I can provide you with hundreds of references, if needed (e.g., reference list available here:[48]). This has been a topic that has permeated through the evolutionary literature for the past 100 years - going back to George Gaylord Simpson, Sewall Wright and many other notable evolutionary biologists - more recently including Richard Lewonton, Stephen J. Gould, Edward Wilson and David Jablonski. I quote from a paper that was co-authored with Lynn Margulis (a highly respected evolutionary biologist)[49]:

"We argue that “symbiogenesis,” an evolutionary concept, has been applied to the concept of evolutionary change less frequently than warranted. “Symbiosis” is simply organisms of different species living in close contact (i.e., the “differently named” beings living together of the 19th century German biologist Anton DeBary; [20]). Symbiogenesis, however, refers to the appearance of new physiologies, tissues, organs, and even new species of organisms as a direct consequence of symbiosis."

I included the preceeding quote because you can see that symbiogenesis has a role in the origin of new species 'as a direct consequence of symbiosis' - which is different than genetic inheritance.Thompsma (talk) 08:21, 7 January 2011 (UTC)

Thompsma, I suspect we are just talking past each other. One thing you do not define, which would be helpful, is where you think I am "incorrect on several accounts".

• Are you saying that the "environmental and developmental" factors affecting guinea pig fur are heritable?
• Are you saying that variations do not need to be heritable to be relevant to evolution?
• I still do not see that the distinction being made between mutations in the simple way of "transcription errors" and recombinations of old alleles in novel formats is really clear enough and important enough for this type of passage. That was a main point of discussion I think? Anyway, I've modified the text a little in the article and it is hopefully OK for you?

What I can see in your new post is discussion about heritability which is not genetic. As far as I can see that is another subject than anything that was being discussed until now (and now I am also looking properly at the article text under discussion also).--Andrew Lancaster (talk) 09:30, 7 January 2011 (UTC)

Andrew...the topic is 'main source of variation' and I would agree the heritable variation is what we would most be concerned about. Here is where you are primarily incorrect: "variations which are not genetic and therefore not involved in speciation or evolution" - this is false genetic reductionism and it has been extensively rejected by the scientific community (for example: [50], [51], [52]). I am assuming that by genetic that you are thinking heritable, which is perhaps why you would place such importance on genetics for speciation in evolution. Of course genetics is important, but it is quite obviously not the only source of heritable variation. For example, in one of the papers I linked too above, published in Nature Genetics Reviews [53], it provides the following definitions:

• Multi-level selection Selection that occurs when relative fitness depends on the properties of individuals, as well as on the properties of the group(s) to which individuals belong."
• Community and ecosystem phenotypes The effects of genes at levels higher than the population. These phenotypes result from interspecific indirect genetic effects, which can be summarized as a univariate trait."
• Community and ecosystem heritability The tendency for related individuals to support similar communities of organisms and ecosystem processes."
• Broad-sense heritability The contribution of all genetic factors (additive, dominant, epistatic) to the total variance in phenotype. H2 is the broad-sense heritability of a traditional phenotype and H2_C is the broad-sense heritability of a community or ecosystem phenotype."
• Narrow-sense heritability The genetic component of phenotypic variance (additive only under random mating) that responds to natural selection."

You are thinking in terms of narrow-sense heritability. If you read through Kevin Laland, John Odling-Smee and Marc Feldman that I linked too above, or the following [54], you can read about the importance and central role of ecological inheritance in evolutionary biology:

"The analysis confirms that niche construction can be a potent evolutionary agent by generating selection that leads to the fixation of otherwise deleterious alleles, supporting stable polymorphisms where none are expected, eliminating what would otherwise be stable polymorphisms, and generating unusual evolutionary dynamics....For example, as a result of the accumulated effects of past generations of earthworm niche construction, present generations of earthworms inhabit radically altered environments where they are exposed to modified selection pressures (14, 15). Previously, we described this legacy of modified selection pressures as an ecological inheritance."

If you have access, this paper (Erwin, D. H. (2008). Macroevolution of ecosystem engineering, niche construction and diversity. Trends in Ecology & Evolution, 23(6), 304-310. doi:doi: DOI: 10.1016/j.tree.2008.01.013) gives an introductory perspective on ecological inheritance. Here is another quote from another researcher (David Jablonski - a paleontologist) that gives perspective on multi-level heritability from another direction[55] :

"Evolution by natural selection can occur at any level where there is heritable variation that affects birth and death of units by virtue of interaction with the environment. This dynamic can occur when selfish DNA sequences replicate disproportionately within genomes, when organisms enjoy fitness advantages within populations (classical Darwinian selection), when differential speciation or extinction occurs within clades owing to organismic properties (effect macroevolution), and when differential speciation or extinction occurs within clades owing to emergent, species-level properties (in the strict sense species selection)."

I am trying to restrict my quotes and references to journal articles that are freely available with pdf access so that you can review the articles for yourself. There has been several articles in recent issues of Evolution that have also discussed heritability at levels above the gene, but I can't find accessible pdfs - for example: Eldakar, O. T., Wilson, D. S., Dlugos, M. J., & Pepper, J. W. (2010). THE ROLE OF MULTILEVEL SELECTION IN THE EVOLUTION OF SEXUAL CONFLICT IN THE WATER STRIDER AQUARIUS REMIGIS. Evolution, 64(11), 3183-3189.

These papers show heritable variations that are not directly under the influence of genetic heritability, yet they contribute signficantly to the evolution of these organisms. For example, the following article (Weinig, C., Johnston, J. A., Willis, C. G., & Maloof, J. N. (2007). ANTAGONISTIC MULTILEVEL SELECTION ON SIZE AND ARCHITECTURE IN VARIABLE DENSITY SETTINGS. Evolution, 61(1), 58-67.) states: "The magnitude of individual versus group selection was relatively similar in the progeny generation, and the observed balance of individual versus group selection across densities is generally consistent with the hypotheses that multilevel selection can contribute to phenotypic evolution and to important demographic phenomena, including soft selection and the “law of constant yield.”"

Moreover[56]:

"This distinction is important in light of the current controversy among evolutionary biologists in which some continue to affirm that natural selection centres only and always at the level of the individual organism or gene, despite mathematical demonstrations that evolutionary dynamics must be described by selection at various levels in the hierarchy of biological organization."

In answer to your questions:

• Are you saying that the "environmental and developmental" factors affecting guinea pig fur are heritable? - No, I simply quoted a paper that discussed what Wright had said and this refuted the claim that the main source of variation is mutation - it was very clear in that quote that this is not the case. I am giving a long supply of peer-reviewed evolutionary articles that genes are not the only heritable factors worth consideration. I'm putting all the citations and quotes in here because so many in here want to reject this notion, yet it is pervasive in the peer-reviewed scientific literature.
• Are you saying that variations do not need to be heritable to be relevant to evolution? - No, and I think I've given an answer to this already.
• I still do not see that the distinction being made between mutations in the simple way of "transcription errors" and recombinations of old alleles in novel formats is really clear enough and important enough for this type of passage. That was a main point of discussion I think? Anyway, I've modified the text a little in the article and it is hopefully OK for you? - I read the sentence: "One source of heritable variation is mutation, various types of which occur during the genetic recombination that happens at reproduction." - it is poorly worded, contrived, and unnecessarily convoluted - please don't take offense. I think that this is happening because you seem to lack a proper understanding of multi-level selection - please don't take offense, many people struggle with this. Once again, this article is giving primacy to genetic reductionism, which seems to be the prevailing viewpoint in the general population here, but not in the scientific literature. If this article is to have a NPOV, then it needs to include a broad perspective on evolution and multilevel selection has been written about in thousands of articles and books throughout his century and last. Here[57] is a recent book that can give you an introduction to this perspective of evolution or you can look here[58] for a more technical account.Thompsma (talk) 18:07, 7 January 2011 (UTC)

Gee, that is a big answer, and it is very hard to see how it relates to anything I wrote. My advice to you would be to make an effort to write in a more compact and focused form on these talk pages. The risk of this approach is that most of what you've written is based on guesses about what I think, because nowhere have you forced yourself to actually quote anything I wrote to prove that you've made an effort to make sure it matches what you are writing. That can of course lead to frustrations all round, and people talking past each other. But I'll do my best:

• the topic is 'main source of variation'. OK it may have been originally a main component of the discussion, but the word "main" was not what I was writing about. I can't see how you could read me that way.
• I would agree the heritable variation is what we would most be concerned about. That clears one point up. Good.
• I am assuming that by genetic that you are thinking heritable. That would be a strange assumption given what I wrote?
• why you would place such importance on genetics for speciation in evolution. Where did I show the specific signs of placing importance on genetics for speciation that you are talking about? It seems important, because obviously genetics is important in evolution, so you must have something quite specific in mind here.
• it provides the following definitions: Are these definitions supposed to show types of heritable variation which is not genetic and can be contrasted with genetically caused variations? If so they plainly don't even from your short quotes. Remember things can have more than one cause. But maybe I simply am not seeing your point here, probably because it is in reply to something you think I think, but which I don't think. Not sure.
• You are thinking in terms of narrow-sense heritability. If you say so? Can you say WHY you think so?
• The first quote supporting stable polymorphisms where none are expected. This quote is supposed to show what? Heritable variations which do not involve genes? What are those polymorphisms?
• The second quote also does not show heritable variations which are not genetic. The contrast with genetic variations and other variations might exist, but not in the examples you are giving, which all involve genes (as well as other things of course).
• The hamster fur quote. Based on your answer to my question I can not see how the quote explains anything about heritable variations?
• it is poorly worded, contrived, and unnecessarily convoluted Again, no analysis of what you mean by this. Please note that this was a simplification of what I found there. Did you notice that? The differences are shown below. Given that this was basically copy editing, what poor wording, contrivance, convolution did I introduce and how does it show I am ignorant please? If you can not actually explain the basis of your remarks how can I or anyone else take them seriously?--Andrew Lancaster (talk) 19:56, 7 January 2011 (UTC)

OLD VERSION. One source of variation is mutation, which introduces genetic changes. These changes are heritable (can be passed on through reproduction), and may give rise to alternative traits in organisms. Another source of variation is genetic recombination, which shuffles the genes into new combinations which can result in organisms exhibiting different traits.

MY VERSION. One source of heritable variation is mutation, various types of which occur during the genetic recombination that happens at reproduction. Having occurred once, these changes can sometimes be passed on successfully to further generations, and may thus give rise to new variant traits in populations. Genetic recombination itself can also shuffle the pre-existing gene variants into new combinations which can result in organisms exhibiting new traits.

What you still have not justified is making a distinction, as in the above passage, between genetic recombination and mutation. Genetic recombination comes within the definition of mutation, doesn't it? So one reason for my edit above was simply to remove an error.--Andrew Lancaster (talk) 19:56, 7 January 2011 (UTC)

I'm sorry Andrew, but I'm having a difficult time understanding your posts - which is why I am being so thorough, so please bear with me. In response to MOST of your questions above where you state That would be a strange assumption given what I wrote? and If you say so? Can you say WHY you think so? - the reason is found in this sentence you posted: The source you now cite is indeed talking about variations which are not genetic and therefore not involved in speciation or evolution. I don't think that the connection could be made any more obvious - you are placing primacy on genetic factors for variation in terms of speciation and evolution, which is why I would say that you are thinking in terms of narrow-sense heritability - in fact, it is almost a precise definition of it!!! In response to some of your other questions about the quoted material - I made certain to post accessible pdf's - so you can read the articles yourself where they describe in detail the answers you seek. I'm not here to provide original research, but to synthesize and replicate what others have published in the scientific (and extended) literature on evolution. You can take it or leave it, but the materials and findings have already passed muster in terms of peer-review. It is not up to us to reject the findings, but to report on what is being expressed by those most competent in the field.

You have swerved this discussion to genetic recombination and mutation, which I never brought up and have no problem with it being included under the definition of mutation. You are correct that the original form of the sentence distinguishing genetic recombination from mutation is a problem - I was simply focused on the fallacy of the first sentence suggesting that the main source of variation was mutation and hadn't gone much further than that. These sentences could be simplified to the following:

SIMPLE VERSION. One source of variation is mutation, which introduces genetic changes. These changes are sometimes heritable (can be passed on through reproduction), and may give rise to alternative traits in organisms. Traits and the mutations that can give rise to phenotypic variation, however, do not operate in isolation but must give rise to an integrated whole and functioning organism. Genetic recombination during sexual reproduction is one way that mutations can be introduced into a population. When sperm and egg fuse, chromosomes can crossover and genes get shuffled about. This process varies the combinatorial expression of dominant and recessive traits and can introduce new characteristics among organisms in each new generation.

Let's look at the guinea pig quote again: "...variation of fur coloration in guinea pigs: genetical, common environmental, and developmental." You state: "I can not see how the quote explains anything about heritable variations?" This quote was taken from a paper that was describing Sewall Wright's original work from the 1910's on guinea pig breeding with his supervisor W. E. Castle (see Wright, S. (1980). Genic and Organismic Selection. Evolution, 34(5), 825-843.). You may need to be familiar with Wright's published research to fully comprehend the quote - tough slogging through that stuff. However, he is referring to three factors: 1) genetical - you understand, 2) common environmental - which is ecological inheritance in modern parlance, 3) developmental - another level (i.e., epigenetic) where heritability exists and Wright expressed this clearly. These are different levels where heritable variation occurs - not just genetic. You might be able to appreciate this better by reading Wright's macroevolutionary perspectives here[59] and here[60]. It is not just the gene that is heritable - but the gene-character interactions that are the heritable units. Of course genes are reliably heritable by virtue of Watson-Crick base pairing, but they are also subject to the forces of natural selection by virtue of their developed or ontological interactions. Even Dawkin's has made this point (sorta)[61]:

"The Williams gene is only incidentally made of DNA. He later (1992) called the generalised version (what I would call a replicator) a codex, adding, “A gene is not a DNA molecule; it is the transcribable information coded by the molecule.”"

Hence, it is the information that is the crux of heritability, not the DNA molecule itself. In this context, Gould & Lloyd[62] (and others - e.g., David Hull) have made the important distinction between replicators and interactors - and so it is the transcribable information that is both replicated and subject to the forces of natural selection via the interaction with other expressed units of transcribable information; this is extending the metaphor of transcribable, such as might be used in "Computer Science: To transfer (information) from one recording and storing system to another." This is where niche construction theory is important (see [63]) - organisms are active agents that modify their environments, which means that the ecological modifications from one generation are transcribable (i.e., form a legacy) into subsequent generations. A termite, for example, inherits its genes from its parents, but it also inherits the termite nest that it did not build itself - yet there it is, a replicable transcribed legacy that influences the selection regime (see page 560[64] for a description of the termite nest example and others). It just so happens that the DNA molecule is well suited as a replicator, but it is not the only replicator out there. Heritability is conditional upon replicators serving as fit interactors.Thompsma (talk) 21:16, 7 January 2011 (UTC)

Responding further to some of your statements Andrew, in particular these two:

1. The first quote supporting stable polymorphisms where none are expected. This quote is supposed to show what? Heritable variations which do not involve genes? What are those polymorphisms?
2. The second quote also does not show heritable variations which are not genetic. The contrast with genetic variations and other variations might exist, but not in the examples you are giving, which all involve genes (as well as other things of course).

These responses suggest that you are not reading the literature I posted, which is important if you are going to understand the material. Many of these papers make an explicit distinction between genetic (i.e., DNA information) and epigenetic (i.e., above the gene) forms of inheritance. Please read the original sources I provide. I will quote from a paper on epigenetics[65] that makes the distinction very clear:

"In particular, recognizing that there are epigenetic inheritance systems through which non-DNA variations can be transmitted in cell and organismal lineages broadens the concept of heredity and challenges the widely accepted gene-centered neo-Darwinian version of Darwinism."

You are mired in the gene-centered neo-Darwinian version of Darwinism, which is fine, but this is supposed to be NPOV with a broadened perspective and those quotes are coming directly from evolutionary journals. Thompsma (talk) 23:11, 7 January 2011 (UTC)

I think it is not possible to have a dialogue like this. Please try to be MUCH more brief and focus upon what is needed for editing this Wikipedia article. Here are some replies to what I think I understand to be your points:-

• I am not disputing epigenetic inheritance exists. Please note that no one has reverted the change from "main" to "one".
• Nevertheless many/most of the examples you want to contrast with genetic inheritance are ALSO examples of genetic inheritance. You seem to me to be making a logical mistake, presumably not found in your sources, by assuming that if two causes can be contrasted then they also must not ever operate together.
• Also just sticking to genetic variations, the contrast you seem to think is so important between "shuffled" genes and novel mutations in the simpler sense is a subtle and debatable point. Please see the mutation article. It does not in any case appear to be relevant here in this already very long article.
• I do not find your "simple version" simpler.
• This article is very long already. I think we have to be careful adding in too many long digressions.

Regards--Andrew Lancaster (talk) 07:40, 8 January 2011 (UTC)

Hi Andrew, this is fine and we will just have to agree to disagree. However, there is no debate that the authors in those papers are saying something very different from your interpretation. I have read each of those papers very carefully, I have discussed these topics with my supervisors and collegues at meetings pertaining to my degree(s), and I have even met some of the authors at conferences where I have personally engaged them on these topics. You need to read the papers to get the depth of meaning. Multilevel selection is a difficult concept to grasp. I would like to suggest that you pick up a copy of 'Evolution in four dimensions' by Marion Lamb and Eva Jablonka or even try to read more on systems theory, holism, epigenetics, and multilevel selection. I don't know how much clearer a point could be made than the quote I left above where it talks about the broadened concept of heredity via epigenetic non-DNA variations - yet you state 'many/most of the examples you want to contrast with genetic inheritance are ALSO examples of genetic inheritance'. Compare this with what Eva Jablonka has to say in her publication: [66]: "Heritable epigenetic variation is decoupled from genetic variation by definition." Sounds like you are misunderstanding the literature to me. DNA methylation, species selection, group selection, symbiogenesis and developmental stability via replicating Darwinian interactors are all examples that have been discussed at great length as examples of non-genetic levels of evolutionary heritability.

The point you think I am trying to make between shuffled genes and novel mutations is not my point at all. You are expressing your thoughts and thinking in terms of the gene-centered neo-Darwinian version of Darwinism. There is another way of understanding evolution that has an extensive academic base in the evolutionary literature. The current state of that paragraph is an editorial disaster, confusing and once again a NPOV of evolution is missed in wikipedia. It is a waste of time to try to argue in here any longer. I'm now convinced that the wikipedian principal is incapable of presenting on this type of topic effectively and accurately. For some reason the evolution article suffers. I will search for a few articles - I don't have them on hand right now because I have to run - but I will compile some reading for you where the authors explicitely state that these lines of inheritance are logically decoupled from genetic inheritance.Thompsma (talk) 01:19, 9 January 2011 (UTC)

One of the distorting effects of gene-centrism is that it forces biologists who are interested in the evolutionary potential of extra-genetic inheritance to focus on the rare cases in which extra-genetic inheritance is relatively decoupled from genetic inheritance (as in the case of Solenposis invicta described above). This is because when genetic and extra-genetic inheritance act in conjunction with one another, the extra-genetic element is inevitably treated as a mere agent or assistant of the genetic element. But it is evident that the real importance of extra-genetic inheritance lies in the contribution it makes to the multi-faceted system which, as a whole, generates the heritable variation on which evolution acts.[67]

Thompsma (talk) 01:44, 9 January 2011 (UTC)

You are apparently talking past me in order to make points you want to make anyway. Problem is that I doubt you'll get much attention because your writing is so-unfocused and wordy, and depends so much on saying that published articles agree with you, rather than defining what it is you are saying. Anyway, concerning me, the papers you have cited can not be in disagreement with me unless those articles have been written as commentaries of this Wikipedia article. There is only one practical proposal I am making about the article right now and that is that the word mutation is often used in a way which covers recombination as well. None of your sources appear to be about word meanings. So I suggest avoiding unnecessary complications by trying to use the term mutation in any way which seems to contrast mutation with recombination in any over-simple way, and I also question whether it is necessary to contrast them at all in an article on evolution.--Andrew Lancaster (talk) 09:25, 9 January 2011 (UTC)

Andrew, the sub-title of this thread is 'main source of variation' - so I'm trying to stay on topic. My argument since the beginning has been that genetic mutations are not the main source of variation and I have provided extensive literature that supports this. I already said above that I have no problem with recombination being a part of mutation - so I don't know why you keep going off track. The papers I posted are in disagreement with what you have said because you are writing things that are in contradiction to the stated facts that I quote. I will repeat the most glaring case in point where you state: "many/most of the examples you want to contrast with genetic inheritance are ALSO examples of genetic inheritance. You seem to me to be making a logical mistake..." Compare this against a quote from the peer-reviewed literature on this topic[68]: "Heritable epigenetic variation is decoupled from genetic variation by definition." Who is making the logical mistake? It was equally surprising when you stated that only genetic inheritance is relevant to speciation or evolutionary change - which is classical genetic reductionism in the strictest sense, it has been proven incorrect, and it is not a NPOV.

You need to have at least an understanding of developmental biology in terms of evolution if you want to discuss the agents responsible for evolutionary variation. Here is yet another quote from a developmental paper, which is where a prudent researcher should be looking to find information about the evolution of variability[69]:

"Genetic change is required for evolution to progress, but with respect to morphology it mainly plays a consolidating role, rather than an innovating one. Physically determined morphogenesis becomes secondarily captured and routinized by genetic circuitry that thus serves to channel and reinforce epigenetic propensities."

What is variation if it isn't innovation? Notice that I bolded mainly in the preceeding quote and I did this because genetic change does not hold the consolidating role exclusively as you have implied. Notice also that I am staying on topic - main source of variation and evolution that are being discussed in these quotes. The next paper I cite, refers again to the topic of evolutionary variation and is explicit about it being non-genetic (i.e., epigenetic) [70]:

"Such mechanisms, termed ‘‘emergent’’ by Salazar-Ciudad et al. (2001a), can not only be employed to produce simple gradients that can act as positional coordinates, but can also ‘‘self-organize’’ patterns of considerable complexity (see below), that are represented 'nowhere in the organism’s genome'."

Gould and Lewonton (1979) also talk about this in their classical evolutionary paper on spandrels[71] where they discuss molluscan shells that show many varations, many of which may have nothing to do with adaptation or genetic inheritance, but are by-products of architectural restraints stemming from what natural materials are available. There is a very large body of lit in evolutionary biology dealing with the principals of self-organized variation and emergence via epigenetic mechanisms that are logically decoupled from genetic inheritance. Kevin Laland and others publishing on niche construction and ecological inheritance have given extensive evidence of non-genetic factors as agents of evolutionary change and variation. Gould and Lewonton (1979) stated - "We support Darwin's own pluralistic approach to identifying the agents of evolutionary change", yet you seem well prepared to accept that only genetic inheritance is the only agent that is worthy of consideration. This is not how it has been written or extensively presented in the evolutionary literature throughout history.Thompsma (talk) 01:30, 10 January 2011 (UTC)

You are not directly addressing anything I or anyone else has written on this talkpage or anything in the Wikipedia article. Indeed it is hard to see any coherent argument at all. These are just scattered quotes about different things, some definitely not relevant. (For example "materials available" i.e. environment, is not heritable.) Please consider WP:SOAP. Epigenetics is mentioned in the article, and the word "main" was even removed.--Andrew Lancaster (talk) 10:44, 12 January 2011 (UTC)

Is genetic mutation necessary for evolution?

Thanks folks, let me ask my question in a slightly different way: is mutation necessary for evolution?

Say we start with some population of fruit flies, split it up into separated groups that cannot physically access each other for breeding, and select out of each unnaturally. First, because we do DNA testing, we remove any individuals from each generation that are born with genetic mutations. We do that in all of the groups so we know whatever variation we observe is not due to mutation. Then we select from different traits in each of the populations. Maybe pruning out the large individuals in one group, the small individuals in another group, the aggressive in the third group, and so on. We do this repeatedly for multiple generations, perhaps even changing the selection criteria as we go along. Basically, we're trying to emulate natural selection in an accelerated fashion. Do we eventually get variation despite the absence of any genetic mutations? How about speciation, eventually? Or is variation and ultimately speciation impossible because there is no mutation? Thanks. --Unflappable (talk) 00:23, 12 January 2011 (UTC)

Mutation is inescapable. Not every cell in your body has the same DNA, identical twins DNA is not 100% identical... when cells divide there are transcription errors in the DNA copying, not all of these are fixed by the cellular proofreading mechanics, and these become permanent mutations in the dna that is propagated through further divisions. Mutations that make a difference for evolution are mutations in germ cells not somatic cells. Therefore even if the parent has a mutation, it doesn't mean that mutation will be heritable, if the cells affected are not the germ cells. Case in point is cancers. — raekyt 00:41, 12 January 2011 (UTC)

A relevant article you may be interested in: DNA Replication and Causes of Mutation By: Leslie A. Pray, Ph.D.. — raekyt 00:45, 12 January 2011 (UTC)

Agreed. Something that seems to cause confusion here is that heritable variation is the key requirement for evolution, and not NEW mutations only or even mainly. As Raeky points out, in any population there are always lots of different genetic variants for every gene. Some of the mutations responsible for those variants may have originally happened a long time ago in some prehistoric animal now forgotten. Nevertheless, at least as far as heritable genetic variation is concerned, mutation in a broad sense (including new combinations resulting from sexual reproduction) is involved as one of the causes. (The possibility of epigenetic or non genetic heritable variations is another matter still being discussed in the literature.)--Andrew Lancaster (talk) 10:44, 12 January 2011 (UTC)

The primary driving force -- in the sense of rapidly approaching optimality -- is not mutation, but recombination. mutation just keeps the search space from getting to small or too narrow. Recombination is what provides an unbiased meta-hueristic search rule that cumulatively incorporates information. in a sense it's like a statistical version of the game "mastermind". you have to incorporate information gleaned from previous trials into the new ones in order to exponentionally approach the solution. and that's what recombination does. whereas mutation doesn't do that at all. e.g. if i was trying to discover the outcome of eight successive coin flips, randomly iterating (mutation) would take me on average 256 tries. but if i do, e.g. 8 trials and you tell me what four of those ahve the higher number of correct results, i can then mix those four into 8 new solutions and repeat (adding a small mutation so i don't accidently filter out the correct solution), and that way i will exponentionally approach the solution. this way the average time to find the correct solution will only increase (on average) linearly with the number of coins, rather than linearly with the number of possible sequences (which is exponentially worse!). Kevin Baas^talk 17:02, 12 January 2011 (UTC)

At least in birds (songbirds) recent evidence suggest mutation rates (genomic evolution) correlate well with diversity. Proc Natl Acad Sci U S A. 2010 Nov 23;107(47):20423-8. Epub 2010 Nov 8.Mutation rate is linked to diversification in birds Lanfear R, Ho SY, Love D, Bromham L.GetAgrippa (talk) 02:19, 17 January 2011 (UTC)