Jump to content

Talk:Evolution/Archive 32

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia
Archive 25←Archive 30Archive 31Archive 32Archive 33Archive 34Archive 35


Reducing the article to 40 kB is bad

Evolution is a very complicated and, by many, poorly understood subject. I can think of few articles more deserving of length than Evolution. Longer articles are accepted for FA, and Evolution should not have to be pared down to be accepted. --Savant13 17:29, 23 February 2007 (UTC)

Reducing the article to 40 Kb is doable

Continuing the article size discussion just above, the article is now at 65 Kb and some FA reviewers said it should be 40 or below. Someone challenged the 40 Kb figure, saying that larger ones have been accepted for FA. Just to get hard numbers, I checked the sizes of six articles that were promoted to FA on 31 January:

55 Kb Vijayanagara Empire
16 Kb Hurricane Ismael
72 Kb Eastern Suburbs & Illawarra railway line, Sydney
31 Kb Hollaback Girl
36 Kb Same-sex marriage in Spain
32 Kb Ivan Alexander of Bulgaria

The average of these six is 40.3 Kb, which confirms that the average FA recently approved is in that ball park, though the standard deviation is large.

I'd personally argue that 40 is better than 65, for Evolution in particular. The present article is hard reading, like a textbook, and I think we are burdening it with more material than it needs. Do people strongly feel it needs to keep all the material it now has? Why can't some of it be off-loaded to the sub-articles that already exist? EdJohnston 01:29, 8 February 2007 (UTC)

Are you checking total size, or prose size? These numbers look unusually small to me. Generally, subarticles good, hard numbers bad :) Opabinia regalis 01:33, 8 February 2007 (UTC)
Total size.. And showing that progress is possible, the total size of Evolution was 103 Kb on 5 January and has come down to 65 Kb over the course of a month. EdJohnston 02:42, 8 February 2007 (UTC)
  • I don't think we should be obsessing too much about size at this point. The size is currently very manageable, and the article's FA changes will not be in any way harmed if we expand it a little more. Compare this article to Charles Darwin, a 98kb featured article on a much more specific and isolated topic than "evolution". We should strive to balance comprehensiveness with conciseness, not merely to balance length with shortness. Raw article length is at best a secondary concern, and honestly is focused on far more often than it should. If an article is as concise as the topic merits, there is no reason to shorten it even if it is long; if an article is as comprehensive as the topic merits, there is no reason to expand it even if it is short. We should thus handle the sections of this article on roughly a case-by-case basis, determining how much coverage each topic merits, and only worry about length as an afterthought, if at all. In other words, yes, "40kb" is doable, but I don't see such an arbitrary number as a remotely important goal, and the enormous number of FAs that are much longer than 40kb affirm this. For example, AIDS is a 110kb featured article; Microsoft is a 92kb one; even Bacteria is 86kb. Readers will not be significantly benefited by having a 40kb article rather than a 45kb article; quality, not quantity (or lack thereof), should be the current primary focus of the article. Yes, we should be trimming off excess details that have accumulated in a number of sections (like "Evidence for evolution"), but we should do so because the information isn't vital enough to understanding evolution, not because we want the article to conform to some arbitrary specific length. Silence 03:36, 8 February 2007 (UTC)
OK, it's fair to make each section the right size for the task it is performing. In your FAR comment you said:

Considering how drastically the rest of this article has been shortened, you may want to consider shortening the "Evidence of evolution" section too, to avoid imbalance. This can be easily done by cutting down on examples and trivial details.

Any suggestion for what's a trivial detail? :) EdJohnston 04:30, 8 February 2007 (UTC)
I've already removed the most egregious examples of trivia bloat in this section, but further work can be done by trimming off unnecessary examples and unnecessary details. For example, it probably isn't necessary to mention the panda's thumb, or to go into such detail on the evolutionary relationships of humans to their closest living relatives: "For example, neutral human DNA sequences are approximately 1.2% divergent (based on substitutions) from those of their nearest genetic relative, the chimpanzee, 1.6% from gorillas, and 6.6% from baboons." Although most of the information in these sections is fascinating and useful, it is not all essential to understanding evolution, or even for understanding the evidence of evolution. -Silence 05:05, 8 February 2007 (UTC)

Basic processes

As I mentioned above, I believe this is the first section we should focus our efforts on improving. Here is the current lead of the Evolution#Basic processes section:

Evolution consists of two basic types of processes: those that introduce new genetic variation into a population, and those that affect the frequencies of existing genes. Paleontologist Stephen Jay Gould once summarized this as "variation proposes and selection disposes".[1] There is a certain amount of variation in apparent traits, or phenotypes, in populations. This phenotypic variation is primarily the result of genotypes, the specific genetic makeup encoded on DNA molecules. There may be one or more functional variants of a gene or locus, and these variants are called alleles. Most sites in the genome (i.e., complete DNA sequence) of a species are identical in all individuals in the population; sites with more than one allele are called polymorphic, or segregating, sites. Interactions between a genotype and the environment may also affect the phenotype through phenotypic plasticity.

We must keep in mind that this will be the first section readers are exposed to after reading the lead section. This is therefore by far one of the most important sections of the page, and needs to be one of the clearest and most informative areas.

The first three sentences are adequate (though I see the Gould quote as optional, since it isn't particularly enlightening to any uninformed readers), but lack a clear explanation of what "variation" is in the first place, in the context of evolutionary biology. Evolution#Variation does nothing to remedy this ambiguity. (I could also see a strong case being made for merging the contents of the "Variation" section with the first "Processes" para, since much of it is relevant to evolution in general, not variation. At the very least this section should be thoroughly rewritten.)

The fourth, fifth, and sixth sentences are not quite adequate, because they lack any explanation of what a "gene" is in the first place. As this is not explained anywhere in the lead section, it looks like somewhere near the top of "processes" is the place to do this, and it's very important that it be done. The fourth sentence is particularly opaque: what is a locus? What is a "site"? "Allele" could also be explained a bit more clearly, and it would be helpful to have a little information on the chemical basis of DNA, genes, etc. Lastly, the end of this paragraph will be complete gibberish to most of our reader base, and I question whether the info on polymorphism and phenotypic plasticity is even relevant here.

One of the central problems with this paragraph is that the topics don't coherently flow together. They seem to be a patchwork of unrelated factoids. The first two sentences discuss variation and its basic processes, but whereas one would expect this to be followed by a brief explanation of these processes (perhaps we could even move the one from the lead section to here, so as to make the lead section more concise and less jargon-heavy), what actually follows is a two sentences spent defining variation of genotypes and phenotypes, which one would almost expect to have been placed before the sentence on variational processes. Then, to make things even more confusing, just as readers are starting to get a grip on the new terms "phenotype" and "genotype", they're barraged with an opaque, technical tangent on alleles and genomes that fails to provide an understandable link to the overall topic, even though it shouldn't be difficult to do so (i.e., directly explain their relevance to variation and its processes). Rather than seeming like a discussion of various aspects of one cohesive topic, the paragraph comes across as a poorly-structured patchwork that will surely confuse or scare away casual readers. What is needed here is a reorganization, expansion, and clarification of this section to improve clarity and informational value for the reader.

Do any people here feel up to the task of rewriting this section? Unlike trivial debates over "see also" and "40kb", this portion of the article is an essential "heart" of the overall topic, and is something that genuinely needs a lot of serious work if this article's ever going to have a shot at FA again. -Silence 04:57, 8 February 2007 (UTC)

Well, although this is the opposite of my area of expertise, I've tried giving a shot at revising this section (and revising the lead section in the process). What do y'all think of this revision? Any glaring errors? I mainly tried to restructure the information in a more meaningful and cohesive way, more clearly explain and define some of the concepts involved, and overall take pains to avoid scaring off readers with unexplained terminology.

Evolution consists of two basic types of processes: those that introduce new genetic variation into a population, and those that affect the frequencies of existing genes.[2] Random copying errors in genetic material (mutations), migration between populations (gene flow), and the reshuffling of genes during sexual reproduction (genetic recombination) create variation in organisms. Genetic drift acts to randomize this variation, and natural selection acts to filter it by favoring beneficial traits.

The variation in a population's apparent traits, or phenotypes, is primarily the result of the specific genetic makeup, or genotypes, encoded on DNA molecules called chromosomes. A specific location on a chromosome is known as a locus; a variant of a DNA sequence at a given locus is an allele. The modern evolutionary synthesis views evolution as the change in the relative frequencies of alleles in a population. The variation between different DNA codings (alleles) at various loci is thus considered responsible for evolutionary change.

Most sites in the complete DNA sequence, or genome, of a species are identical in all individuals in the population. Consequently, relatively small genotypic changes can lead to dramatic phenotypic ones. Sites with more than one allele are called polymorphic, or segregating, sites. Polymorphism leads to distinct groups arising within the same species, such as the division of organisms into male and female sexes. Interactions between a genotype and the environment may also affect the phenotype, through phenotypic plasticity.

—Preceding unsigned comment added by Silence (talk • contribs)

Should we add in first paragraph's sentence a mention of gene flow:Genetic drift acts to randomly increase the occurrence of a trait, gene flow acts to homogenize a trait, and natural selection acts to propagate a favorable beneficial trait. I added a mention of gene flow, and I have noted many people take exception to "filter" so I offer "propagate" (reproductive success). Genetic drift doesn't randomize but randomly increases a trait as a stastical effect. I would also suggest: Interactions between a genotype and the environment may also affect the phenotype, and this is reflected in developmental and phenotypic plasticity. Maybe a better example of polymorphism would be in coloration of hair or bird plummage, or variations in butterfly or moths. This is much improved over the original version. My suggestion for the first paragraph doesn't fit in the structure as I look at, but I think Silence can fix it. Genetic drift acts randomly increasing the occurrence of a variation, gene flow acts to homogenize a variation, and natural selection acts to propagate a favorable variation as a beneficial trait. ??? Still awkward but I like Silence's idea for this sentence as it fits reality in that all the processes occur simultaneously. Population structure and other factors can influence what dominates but all can be at play. Sheez, It is a lot easier to criticize than offer solutions. I tend to become long winded as I think how to address it. I like it pithier. GetAgrippa 18:16, 8 February 2007 (UTC)
I've tried to implement some of these ideas; feel free to fix anything you can word better (I'm especially unsure that I'm explaining polymorphism clearly). Could you clarify for me what you mean by "gene flow acts to homogenize a trait/variation"? We should try to word this more simply in the article. -Silence 05:10, 9 February 2007 (UTC)
Well the more I think about it many editors would say just develop gene flow later in article. Gene flow tends to spread a gene around so it is homogeneous in a population. Often populations are isolated and migration can bring in new genes, or HGT, or hybridization within similar species. Because speciaton is usually the divergence and isolation of gene pools within a population to generate a new species, gene flow is usually considered to be counterproductive to speciation. I also think your example of polymorphism is fine. I think it is excellent sorry for the knee jerk. So lets leave like it is and move on to History? GetAgrippa 12:59, 9 February 2007 (UTC)

I've fallen ill, but did a lot of work on a section of Basic processes, so please take what you can use from Talk:Evolution/Gene flow. Adam Cuerden talk 12:42, 9 February 2007 (UTC)

There is a serious gap in the basic processes section in that 'replication' is left out. It is my understanding that evolution can only occur in systems where there is some form of replication, or more precisely, replication with variation. This should be made clear. The full algorithm is replication with vairation then selection. Evolution can be observed in many other systems. I hope the article can be modified to reflect the importance of replication to evolution. steven 11:09, 19 February 2007 (UTC)

.Understanding Evolution from University of California, Berkeley

.EvoWiki, a wiki dedicated to education about evolution

.Everything you wanted to know about evolution (provided by New Scientist)

.Howstuffworks.com — How Evolution Works

.Synthetic Theory Of Evolution: An Introduction to Modern Evolutionary Concepts and Theories

.Evolution News from Genome News Network (GNN)

.Understanding Evolution: History, Theory, Evidence, and Implications Deals heavily with the history of evolutionary thought

.Becoming Human - Journey through the story of human evolution

.Timeline of Evolutionary Thought The life and work of notable people who have contributed to evolutionary thought

.Talk.Origins Archive — see also talk.origins

.Dispelling the Top Ten Myths About Evolution Endorsed by Ann Druyan and the American Association for the Advancement of Science: introduces the top ten common myths and misunderstandings about evolution and includes a sample chapter, "Survival of the Fittest".

Evolution simulators

.Isolated species evolves to interact more efficiently with its environment (java applet)

.Watch small creatures evolve into more efficient swimmers

.Blind Watchmaker Applet

We could pair it down to these for this article and move the others to supporting articles. This is fourteen. We could move Top Ten Myths also to make thirteen. We could also pair down the simulators to just two examples also (I would drop the first and use the last two). That would be twelve. The Darwin's writings is one I hesitate to remove, but I did. This is a suggestion in response to reducing the number of links. GetAgrippa 06:13, 8 February 2007 (UTC)

I'd be inclined to keep Darwin's writings and remove the "top ten myths" and Talk.Origins links. They aren't really needed, as their focus is specific and addressed more by other articles; if they have some valuable info, use them as references for specific parts of the article (for example, our re-implementation of the info from the "misunderstandings" section) rather than external links. I'm also inclined to remove all or most of the evolution simulators. And I'd move some of the ones above to daughter articles: "Becoming Human" to Human evolution, "Timeline of Evolutionary Thought" to History of evolutionary thought, etc. And, though I'm hesitant to suggest this, we should consider removing the link to "EvoWiki"; wikis are not reliable sites as a rule, and should not be our first choices for external links. The EvoWiki article was also recently deleted for being non-noteworthy, so notability is clearly not a valid reason for keeping it around (as contrasted with Darwin's writings). -Silence 07:01, 8 February 2007 (UTC)
The Darwin's writing I felt the same as well as removing the top ten myths. I don't care much for the simulators either,but I thought some maybe interested. I agree with the Evowiki too, but generally people often refer to Panda's thumb or Talkorigins. Some of the content is out of date in Talkorigins, but many refer and defer to it. Your suggestions about becoming Human and the Timeline seem reasonable. I just didn't want to cut and slash everything. Let's see where this goes:

.Understanding Evolution from University of California, Berkeley

.Everything you wanted to know about evolution (provided by New Scientist)

.Howstuffworks.com — How Evolution Works

.Synthetic Theory Of Evolution: An Introduction to Modern Evolutionary Concepts and Theories

.Evolution News from Genome News Network (GNN)

.Understanding Evolution: History, Theory, Evidence, and Implications Deals heavily with the history of evolutionary thought

.Talk.Origins Archive — see also talk.origins

.National Academies Evolution Resources

.Charles Darwin's writings online

I removed suggestions, except Talkorigins cause I think many will have a fit. I added Darwin's writings, and I added the NAE resources which pares it down to nine. If we drop Talk.origins then it will be eight, but we could probably still reduce it more as there is some redundancy in the basic evolution sites. However I think many will find one site or the other to their liking. GetAgrippa 13:24, 8 February 2007 (UTC)

"I just didn't want to cut and slash everything." - I don't think we should be too concerned about this, honestly. If an external link doesn't meet all our standards, we should simply remove it; if that leaves us with 10 external links, so be it. If that leaves us with 5, so be it. If that leaves us with none, so be it. No article on Wikipedia has ever lost an FAR for having not enough external links; Wikipedia, ideally, wouldn't have any external links (because it would be self-sufficient on all relevant topics), except when an article is discussing a website, or when one is being used as a reference for a claim. It's a flaw of Wikipedia's that we need external links. Therefore, although we should use external links when they are greatly helpful to our readers, and entirely relevant (and, preferably, noteworthy enough), there is no "minimum" of external links that any article needs.
Also, I still recommend removing TalkOrigins for the simple reason that it's a site about the creation-evolution controversy, not simply about the science of evolution. As this article, Evolution, is solely about the science of evolution, not about the social controversy, it is potentially misleading of us to link to TalkOrigins prominently in our "links" section, because it suggests that this article is meant to discuss that controversy in-depth, or, even worse, it suggests that the science of evolution is controversial! If we were to link to a site for any Usenet newsgroup, then if anything we'd link to one for sci.bio.evolution, not for talk.origins, at least on this page. Although the TalkOrigins Archive is certainly an excellent resource, its chief concern is with rebutting creationist claims by teaching evolution, not just with teaching evolution. Consequently, although it's perfectly OK to link to various talk.origins pages as references to back up various claims on this article, we shouldn't include it in our "external links" section outside of such a context. -Silence 20:36, 8 February 2007 (UTC)
I agree with your analysis of Talkorigins, and I have always thought too much time was spent dealing with creation-evolution controversy than the topic. It takes up space that could be better spent developing the topic. I think many feel strongly about the controversy, but technically your description is accurate for this article. Let's drop it here and move it elsewhere. GetAgrippa 13:22, 9 February 2007 (UTC)

User:GetAgrippa is proposing we reduce the external links to *these nine*:

  1. Understanding Evolution from University of California, Berkeley
  2. Everything you wanted to know about evolution (provided by New Scientist)
  3. Howstuffworks.com — How Evolution Works
  4. Synthetic Theory Of Evolution: An Introduction to Modern Evolutionary Concepts (anthro.palomar.edu)
  5. Evolution News from Genome News Network (GNN) (genomenewsnetwork.org)
  6. Understanding Evolution: History, Theory, Evidence, and Implications (rationalrevolution.net)
  7. Talk.Origins Archive — see also talk.origins
  8. National Academies Evolution Resources
  9. Charles Darwin's writings online

I see that he's proposing to drop the simulators as well. (None of these changes has been made yet). Reducing the number of external links is taken very seriously in FA reviews. (Some of the links being dropped may find a home in one or more subarticles).

Please respond if you care about this set of external links, in either direction. We need a Talk page consensus if at all possible. If you don't care at all, it would still be helpful to get your comment. EdJohnston 15:52, 8 February 2007 (UTC)

  • Agree with the caveat that we keep all links in other articles. We should retain this material but not necessarily in this article. This article has to be accessible and not too clogged with stuff. That is why we have daughter and granddaughter articles.--Filll 18:03, 8 February 2007 (UTC)
  • Agree as Filll, with the comment that Talk.Origins Archive would be better with the internal link referring to TalkOrigins Archive, and with a few words of explanation such as "provides scientific responses to misunderstandings and common arguments." ... dave souza, talk 16:44, 9 February 2007 (UTC)

I went ahead and made the above changes, since all those who responded were in favor. I tweaked the talk.origins entry as recommended by User:Dave souza. User:Silence argued for its removal, but I didn't believe I had a mandate for that yet. Someone else who believes the Talk page favors removal can do it if they want. In any case talk.origins is still linked from one of the references. Note we have two articles, talk.origins and TalkOrigins_Archive. I doubt that we need to keep both. Someone who is a fan of talk.origins might want to apply a Merge banner to one of them. EdJohnston 19:41, 9 February 2007 (UTC)

The problems are with the lead

Many of you seem to think the problems with this article are the Basic Processes section or the number of links. I think the worst aspect of the article by far is the lead. The first sentence is barely literate, and the remainder is much too technical, violating the WP:LEAD policy: "The lead ... should be written in a clear and accessible style so that the reader is encouraged to read the rest of the article". As it stands, the lead will put off all but the most determined reader. This is a pity, as it gives the impression that evolution is a highly technical subject that can only be understood with technical jargon, whereas in fact the key ideas are beautifully simple, as explained in the far superior Introductory article. This has all been pointed out before, eg by Raul654 (" technical articles should be - at least partially - accessible to layman") and Filll ("the introductory paragraphs, or at least introductory sentences, of all sections should be accessible to the average reader") in the FAR, but nothing has been done about it. I suppose the problem is that the editors are experts in the field and do not realise they are using unfamiliar jargon. Poujeaux 10:37, 9 February 2007 (UTC)

Here is a list of some terms that will not be familiar to the average interested reader which should not appear in the lead: heritable, traits, alleles, speciation. In fact this is easy to fix: heritable -> inherited, traits -> characteristics, alleles - no need to mention, just say genes, speciation - no need to mention, just say new species. Poujeaux 10:46, 9 February 2007 (UTC)

This has gone round and round. This is not a Simple Evolution article, so some words are accurate to use for any high school audience. Actually it was more complicated, then less. This is closest to a compromise. I didn't write it and I agree with being accessible, but it seems the accurate nomenclature would serve students who use it as a reference. Of course entering a new subject there will unfamiliar nomenclature, but that is the process of learning. The nomenclature does need to be defined. An allele is not jargon and without understanding that you know nothing of modern evolution or population genetics. GetAgrippa 11:52, 9 February 2007 (UTC)

Given hthat "alleles" and "speciation" are glossed, I don't think they're a problem. inherited characteristics works, though. The first sentence s particularly hard. Adam Cuerden talk 12:15, 9 February 2007 (UTC)

  • I agree that the first sentence would be much, much easier to understand if we changed "heritable" to "inherited"; this is a much simpler and more common English word, and thus normally very preferable. The only reason I haven't already made the change myself is because it looks to me like "heritable" and "inherited" have two different meanings, at least in the context of biology. "Inherited" refers to heredity, whereas "heritable" refers to heritability. If this distinction is, in the context of the first sentence of this article, nonexistent, unimportant, or misinterpreted as it currently stands, then I fully support the change to "inherited". If not, however, then we should not introduce inaccuracies for the sake of clarity.
  • I strongly disagree with changing "traits" to "characteristics". If anything, I feel that the former term is actually simpler, and easier for laypeople to understand, than the latter. The fact that it's also the correct biological term is just a bonus. We're hugely fortunate to have a rare example of an easily-understandable biological term in "trait".
  • I disagree with removing all mentioning of "allele", as this is arguably, next to gene, the most important term for understanding modern evolution, considering that the very definition of evolution is generally stated in terms of alleles. To not mention alleles in the lead section of evolution is like not mentioning strings in the lead section of string theory; the fact that a term/concept is obscure or difficult to understand doesn't make it non-integral to a field. I've already removed most of the mentioning of "alleles" in the lead section (in fact, there's probably about 1/10 as much stuff on alleles now than there was in the past), so there's little chance of this aspect of evolution "throwing" anyone.
  • As for the speciation bit, that's a more interesting one to discuss. I think there is a strong argument to be made for rewriting the second and third sentences of this article from scratch. These lines are definitely much clumsier and than most of the rest of the lead section, and I'm sure there are better ways to word the ideas involved. I agree that we don't necessarily have to mention speciation in the lead section, though I don't see any strong reason not to, if doing so makes it easier to explain the topics involved at that stage. But, then again, I'd like to know whether we're already emphasizing the "species-to-species" transition in that lead section of evolution too much. It's been pointed out that the distinction between different species is largely arbitrary; there is no clear demarcation point between one species and another, but rather a gradual continuum, which only in retrospect (when all the transitionals have gone extinct) seems sudden. We thus risk misleading our readers on this point if we over-emphasize species and speciations in the lead section, in trying to explain common descent. This part of the article could probably use the most revision and brainstorming, if only to think of simpler and more coherent ways of explaining this crucial point of evolution (as well, ideally, as ways that flow better with the overall lead section than the current wording does). -Silence 12:22, 9 February 2007 (UTC)
I've had a go at a rewrite, though you may be right about "traits". (I think that the diference between inherited and heritable is only a matter of view: if you look at it from the view of the parent, heritable, of the offspring, inherited. The distinction doesn't matter if you're looking at it over arbitrary numbers of generations. I've also attempted to add clarity by filling the gaps between changes in allele frequency and speciation a bit - I imagine you'll want to tweak it, but the idea is probably good. Adam Cuerden talk 12:39, 9 February 2007 (UTC)

By the way, I still have that section on Gene flow, but am too ill to work on it. Feel free to steal from my notes: Talk:Evolution/Gene flow

I agree that the processes of evolution are two phases-processes of variation and processes that propagate traits, but the definiton here is the outcome of evolution that we can measure and what evolution is. A genomic change in a population with successive generations. That is a working definition that we can develop into how it comes to be (through variation and natural selection, etc.), so I think keeping it simple in the first paragraph will keep more editors happy. I do agree that an emphasis on speciaton is misleading as people equate evolution with speciation, whereas speciaton is a by product of evolution just like character displacement. Evolution is not synonymous with speciation. The debate on speciation is perspective also in morphological, biological, and ecological. There is a movement to reduce speciation to a genetic barcode until the debate can be worked out. I like the idea of building from simple to complex to offer a simple answer and more info for the inquiring mind.GetAgrippa 14:36, 9 February 2007 (UTC)

Aye. I was trying - others may disagree at how well I did - to give a first sentence that's a bit broader, then give three other "definitions" looking at it from progressively wider angles - in short, to try and get all of a broad subject briefly laid out in the first paragraph. We can then expand a bit on that from there on out. Since the first sentence is supposed to define the topic, I expanded it a little to include some of the things that are, of course, consequences of the changes in traits, but not very obvious at first glance. I suspect that by the time we're done, it'll look completely different, but it's not bad for a start. Adam Cuerden talk 14:50, 9 February 2007 (UTC)

Thanks Adam I think your edits are a big improvement! I do appreciate that the first para is very difficult to write. Silence, I disagree about 'traits', I dont think this is a word familiar to laypeople? Poujeaux 15:24, 9 February 2007 (UTC)

Previous version (1st para) Current version (2nd para)
In biology, evolution is the change from generation to generation in how common various inherited characteristics are within a population. These characteristics are encoded on genes. Competing variants of genes, known as alleles, cause different characteristics to become more common in different organisms, resulting in variation between organisms with different alleles. As these differences in and between populations accumulate, new species can evolve from prior ones. All known species are descended from a single ancestor through this process of gradual divergence. In biology, evolution is the change from generation to generation in how common various inherited characteristics are within a population, and the long-term consequences of this. The competing variants, known as alleles, of the genes that encode these characteristics are not necessarily equally advantageous for the organism that has them. Organisms with more of the advantageous alleles are more likely to survive and reproduce, passing those alleles to the next generation. As several possibilities may be equally advantageous, but mutually exclusive, over time, two populations can diverge, and new species can evolve from prior ones. All known species are descended from a single ancestor through this process of gradual divergence.
  • I'm not fond of some of the most recent changes. Specifically:
  • "and the long-term consequences of this" - Is this really necessary? It seems either trivially true (any process that goes on for a while can have long-term consequences, which means that those consequences are a part of the process) or misleading (dictionary definitions don't usually define the history of life as being a part of the word [i]evolution[/i], contrary to creationist assumptions).
  • "The competing variants, known as alleles, of the genes that encode these characteristics" - That's really, really, really circuitous wording that will probably stop most readers in their tracks and cause them to either have to reread the sentence a few times to parse it, or just give up on it and move on or leave the article. I much prefer the previous, two-sentence version, if only for the sake of clarity and helping space out the term introductions more (i.e., genes are introduced first, then alleles afterwards, giving readers time to keep up). Because you put "these characteristics" at the end, it isn't clear what characteristics are being referred to (whereas the old wording made it clear that it referred to "inherited characteristics" in the first sentence; it isn't clear what an "allele" or a "gene" is meant to be in this sentence; and it isn't clear how the parts of the sentence are meant to flow together as a cohesive whole, unless one already knows what alleles and genes are. In other words, this is a useless construction for our reader base.
  • "are not necessarily equally advantageous for the organism that has them" - And even I don't know what this means. Why the "necessarily"? What does "equally advantageous" mean, and why is only a single organism (rather than a population) being discussed, rendering it impossible for two alleles of the same site to actually be competing within that organism? Again, this line seems either trivially true (and thus not worth explaining) or misleading, depending on how one interprets it.
  • "Organisms with more of the advantageous alleles are more likely to survive and reproduce, passing those alleles to the next generation." - By this point, most readers probably won't at all comprehend what "alleles" are because of the early ambiguity in explaining them, making this sentence unparsable too. They also won't understand what "advantageous" means in this sentence or the previous one, because it hasn't been explained that an advantageous trait is one that helps an organism survive and reproduce. None of this was unduly ambiguous in the previous wording. I also don't see the point of saying "more of the advantageous alleles", as this implies that it's a sheer matter of quantity; surely an organism with 20 advantageous alleles may be less fit than one with 10 advantageous alleles, if the latter organism has more important advantageous alleles. Moreover, it implies that advantageousness is an inherent quality of alleles, rather than situational and conditional.
  • "As several possibilities" - Several possibilities? Possible whats?
  • "may be equally advantageous, but mutually exclusive," - This makes absolutely no sense to anyone who doesn't already undersatnd evolution. I don't even see the relevance of value in it for those who do.
  • "over time, two populations can diverge, and new species can evolve" - This is a horrifically poor explanation of speciation, because it mistakenly repeats the misconception that all speciation is cladogenetic. It also mistakenly implies that two competing populations must be equally fit in order for both to survive; this repeats the even more common misconception of "survival of the fittest", when in reality it is not at all necessary for two groups of organisms to have equally advantageous traits; all that's necessary is for each to have sufficiently advantageous traits that those traits continue to be propagated. -Silence 16:01, 10 February 2007 (UTC)

My thoughts:

  • "...and the long-term consequences of this" - I'd like, in some way, to hint that evolution has higher-level consequences that are also part of its study, e.g. Universal Common Descent, speciation, etc, since the first sentence is meant to encompass everything evolution, ideally. That said, that particular phrasing is a bit awful.
  • "The competing variants, known as alleles, of the genes that encode these characteristics"... How about we just cut mention of alleles? Definition of terms is not the most important part of the lead.
  • "are not necessarily equally advantageous for the organism that has them" In other words, they could - but need not - have a differing effect on fitness of the organism.
  • "Organisms with more of the advantageous alleles are more likely to survive and reproduce, passing those alleles to the next generation." Agreed, but I'm trying to avoid the word "frequency", and "more advantageous alleles" is ambiguous as to whether it applies to alleles or advantageous. Actually, perhaps I chose the wrong disambiguation.
  • "As several possibilities" - posssible evolutionary paths, possible niches, mutually exclusive strategies - pretty much any possibility you want.
  • "may be equally advantageous, but mutually exclusive," - In other words, you can't bee both a small scavenger and a large predator.
  • "over time, two populations can diverge, and new species can evolve" - Point, I knew I was simplifying a fair bit - may well have gone too far.

Eh, well. not ridiculously bad for someone with severe flu. Edit away. Adam Cuerden talk 17:06, 10 February 2007 (UTC)

"Universal Common Descent, speciation, etc, since the first sentence is meant to encompass everything evolution, ideally." - But the theory of common descent is not part of the process of evolution; at best, it's part of the modern synthetic theory. And speciation, in addition to indeed being constituted only by changes in characteristics, is not an especially important aspect of evolution; really, it's over-emphasized too often. It is redundant to state that long-term evolution is a part of evolution, as that's true by definition; we should not try to be so all-encompassing that we lessen the sentence's clarity and conciseness.
"How about we just cut mention of alleles?" - I don't see anything wrong with the explanation of alleles in the last version. It was as clear as possible.
"In other words, they could - but need not - have a differing effect on fitness of the organism." - That's not just other words, that's entirely other meanings. Nothing in that sentence conveys the fact that characteristics sometimes affect fitness, and sometimes don't.
"Agreed, but I'm trying to avoid the word "frequency"," - The last version didn't use the word frequency, did it?
"posssible evolutionary paths, possible niches, mutually exclusive strategies - pretty much any possibility you want." - That sort of vagueness is inappropriate for the lead section, as it means that the line is noninformative.
"In other words, you can't bee both a small scavenger and a large predator." - Again, the problem isn't that I don't understand the line, it's that our readers won't. Saying "in other words X" to me on a Talk page doesn't make the line any less ambiguous in the context of the article. -Silence 19:00, 10 February 2007 (UTC)
You are, of course, quite right. I've looked ovber what I did, and, lo, it was awful. I've basically replaced all my awful sentences with... well, the old second paragraph, which was detailed and informative (and works well when combined, i.m.o) —The preceding unsigned comment was added by Adam Cuerden (talk • contribs) 19:15, 10 February 2007 (UTC).

Should we lose the third paragraph of the lead?

The theory of evolution by natural selection was first put forth in detail in Charles Darwin's 1859 book On the Origin of Species. In the 1930s, Darwinian natural selection was combined with Mendelian inheritance to form the modern evolutionary synthesis.[5] With its enormous explanatory and predictive power, this theory has become the central organizing principle of modern biology, providing a unifying explanation for the diversity of life on Earth.

This potted history seems a little awkwardly placed, and I think we'd be better off spending a little more time on, say, speciation, or universal common descent in the lead, instead of just a sentence in the opening paragraph. Adam Cuerden talk 15:00, 9 February 2007 (UTC)

No, despite my remarks above, I like this bit, so please dont cut it. It satisfies the WP:LEAD bit about context and making the reader want to read on. Poujeaux 15:26, 9 February 2007 (UTC)

Would going to four paragraphs be appropriate, then? Adam Cuerden talk 15:42, 9 February 2007 (UTC)

I don't see the need. Why not try to explain these things in the article text, rather than trying to cram everything into the lead section? -Silence 16:01, 10 February 2007 (UTC)

Because the lead section ought, at least in theory, be able to stand as a short, accessible article on evolution in its own right, at least as I understand WP:LEAD. Perhaps it would be useful to have a discussion on exactly what needs to be in the lead? Adam Cuerden talk 18:37, 10 February 2007 (UTC)

Well, I've always thought this lead was pretty good. Are we looking for perfection (which reminds me of the old engineering adage, "the greatest enemy of good enough is perfection")? This lead meets some minimum standards: it's readable (and therefore accessible), it summarizes evolution in a few words, and is NPOV. Let's not tweak it too much, or we might have all kinds of issues, not the least of which are complaints from the anti-evolution groups. Orangemarlin 18:44, 10 February 2007 (UTC)

Wolbachia

The bacterium Wolbachia has a deep impact on the evoltion of among athropods. http://unisci.com/stories/20011/0208011.htm Where would it fit in in the article? 193.217.193.118 15:55, 9 February 2007 (UTC)

Hmm. Arms races? Though I don't think we actually have a section on that... we really should. Adam Cuerden talk 17:45, 9 February 2007 (UTC)
For that matter, Evolutionary arms race needs a lot of work too. Adam Cuerden talk 17:57, 9 February 2007 (UTC)
Why not add it under a new section for "Competition", right above or below Evolution#Cooperation? We seem to over-emphasize cooperation in our current article, in order to help correct that old "survival of the fittest" misconception; but competition is highly important in evolution too. -Silence 03:57, 10 February 2007 (UTC)

Thanks to Editors

I really appreciate the effort of cooperation to improve this article. I would be the first to admit that I can be contrary. It reminds me of the contrary indians in the movie Little Big Man with Dustin Hoffman. Anyways lets keep it going while we have the momentum. GetAgrippa 18:36, 9 February 2007 (UTC)

Poll/survey

I think it would be useful to figure out what, exactly, SHOULD be in the lead, because, let's face it, it's not like it's particularly lenthy. To this end, I've taken every section of the article (for convenience), and set up a short poll/survey as to how much of its contents needs to be in the lead. Give as much detail as you like.

Of course, this is just to get an idea as to whether anything in particular is missing: I don't expect this will lead to substantial rewrites, but it'll point out if we should fit anything more in. Adam Cuerden talk 19:38, 10 February 2007 (UTC)

Basic processes
Variation (encompassing Mutation, Gene flow, and Horizontal Gene Transfer)

How much detail should we give to variation?

  • Leave it out/Mention it if it's useful to explaining something else
  • Variation should be discussed only insofar as it is necessary to understand evolution and natural selection. Because there's an entire section on variation immediately after the lead section, we can reserve the post-lead text for explaining mutation, gene flow, horizontal gene transfer, variation, etc. However, if there is a clear, concise, and useful way to briefly mention variation in the first or second paragraph, I'm perfectly OK with that too; it's just not a top priority, because it's better not to mention it at all than to half-ass it and not properly inform our readers as to what genetic variation is. -Silence 19:19, 10 February 2007 (UTC)
  • Explain it briefly, but don't go into detail as to what causes it
  • Explain major causes.
Basic processes
Heredity (includes Recombination)

How much detail should we give to heredity?

  • Presume that it's understood/leave out
  • Only as far as needed for other things
  • Brief explanation
  • Sentence or two.
Mechanisms of evolution
Natural selection

How much detail should we give to natural selection?

  • Brief
  • Fair bit, not first paragraph
  • Reserve the first paragraph for the process of evolution (including heredity, common descent, variation, etc.) and the second paragraph for the mechanisms (which we've now simplified to just natural selection, which gives us plenty of room in that paragraph alone for natural selection.) Natural selection is the most important evolutionary mechanism to explain in the lead section because it's the only one that explains adaptation; without natural selection, evolution is essentially random, and the mistaken notion that evolution is random is an important one to nip at the bud. Besides, it makes for a smoother transition into the third paragraph, where Darwin is mentioned. -Silence 19:19, 10 February 2007 (UTC)
  • Needs to be briefly mentioned in first paragraph, as a major process, but main detail later
  • Needs to be briefly mentioned in first paragraph, as a major process, but no further detail
  • Explain in reasonable detail in the first paragraph.

(Of course, these may be trumped by writing considerations)

Genetic drift
  • Leave out
  • Too complicated to explain concisely in the lead section, plus there's a perfect space to explain it immediately after the lead section, at the top of "basic processes". -Silence 19:19, 10 February 2007 (UTC)
  • mention/emphasise the random component of evolution, but leave out the term.
  • explain, using term.
Speciation
  • Leave out
  • Only as far as needed for other things
  • I added this option because I don't think we should necessarily leave it out, but I also don't think we should necessarily explain it; speciation is not important enough that we need to devout much time to it, but we can explain it if doing so helps more clearly or usefully explain other aspects of evolution. If not, then not mentioning it is no great loss as long as we still convey the general ideas of heredity, divergence, common descent, etc. Whether we talk in terms of populations or species makes little difference. -Silence 19:19, 10 February 2007 (UTC)
  • I tend to agree - it's probably useful for UCD, nothing more. Adam Cuerden talk 19:38, 10 February 2007 (UTC)
  • Explain briefly
  • detail major causes (be specific as to which)
  • Special: Do we need to explain the concept of different evolutionary paths?
Extinction
  • Leave out
  • Almost everyone will already know about this, it's not a part of the process of evolution per se, and anyone who doesn't know about extinction probably won't be able to get a grasp on it in an extremely short time anyway. However, if extinction can be worked into the paragraph in an especially useful and concise way, I'm open to the possibility of including it. -Silence 19:19, 10 February 2007 (UTC)
  • Ditto Adam Cuerden talk 19:38, 10 February 2007 (UTC)
  • Include
Cooperation and competition
  • Leave out
  • Include
  • Include only to explain the competition between traits and/or alleles.

-Silence 19:19, 10 February 2007 (UTC)


Evidence of evolution
  • Leave out
  • Include a few
  • Include! Evidence and arguments for it need to be included. So does evidence and arguments against it. Show both sides of the debate on origins. ````oddball 2002
  • Despite what some people say and believe, evolution is not proved. It is a belief system based upon fundamental faiths. Some of these assumptions are listed here:

Obviosly, evolutionists believe that a cell can come into existence by natural forces. Evolutionists believe that a cell can become another type of cell by accidental mutations- they admit that as mutations tend to be destructive rather than constructive and this makes it necessary for a cell to be randomly created which has the ability to reproduce. This cell also has to be able to make its own food, like a plant can. Also, these mutations must be in the DNA of the young. They also must believe that all this not only can happen, but that it did happen, that is: Nonliving things gave rise to living things;that is, spontaneous generation occured Living things became more complicated over a proccess of random mutations occuring constantly over billions of years. ````oddball 2002

Oddball, you seem somewhat confused. Evolution has nothing to do with the origin of life (that's a separate field): it's a process of development of existing life. It's an ongoing process that can be directly observed: so, in that sense, it's "proved". Also, there isn't any "evidence against it" that could be presented. But we already have an Evidence of evolution article elsewhere (and plenty of stuff on creationism) - I don't think we need to include anything more than a wikilink. --Robert Stevens 14:45, 2 March 2007 (UTC)
Oddbaall, please learn how to sign your posts with --~~~~. Also, what you are describing is not part of evolution, so you are just wasting time here. Why not learn something about science and evolution first? You might start with the FAQ above.--Filll 15:33, 2 March 2007 (UTC)
Ancestry of organisms
  • Leave out
  • mention the fact of universal common descent, not first paragraph
  • mention the fact of universal common descent, first paragraph
  • more detail?
History of modern evolutionary thought
  • Leave out
  • Sentence or two
  • Paragraph
Misunderstandings/Social and religious controversies
  • Leave out
  • Include

Other considerations

  • Do we need to include the term "allele", or should we just use "genes", with appropriate qualifiers?
  • "Traits" or "characteristics"?
  • I prefer "traits" and find it simpler than "characteristics" (not to mention shorter), but since several users have supported the view that "characteristics" is significantly simpler, I'll go with the consensus on that. Though we still need to decide on where we're going to make the transition from "characteristics" to "traits" in the article, since presumably we can't spend the whole page talking about characteristics! This is probably the main problem with using "characteristics" for the lead section: we risk confusing our readers enormously when they move on to other parts of the page and suddenly learn that the terminology has completely switched. Sometimes trying to simplify things too much for reades causes more ambiguity than it resolves. Currently, I've made the transition from "characteristic" to "trait" in the 2nd paragraph. -Silence 19:19, 10 February 2007 (UTC)
  • Should we define it first in terms of changes in traits (or characteristics), or in terms of genes? One may be simpler, the other is more how it tends to be measured in scientific studies?
  • Is "frequency" a difficult word?
  • Not really. It's about as difficult as "generation". We can use a simpler word only if it's clearer to do so; if our replacements for "frequency" are too convoluted or ambiguous, then we shouldn't bend over backwards to not use the word, especially since it's accurate. -Silence 19:19, 10 February 2007 (UTC)

Adam Cuerden talk 18:59, 10 February 2007 (UTC)

As a non-expert, "of the variant genes, known as alleles that encode these characteristics" is still confusing. (a) if this is going to stay, need a comma after alleles (b) Its not clear what an allele is - how does it differ from a gene? What does "variant genes" mean? Clicking on alleles doesnt help. Do we need to have alleles in the lead?
Otherwise the present version looks good. The "characteristic" to "trait" transition is good. Poujeaux 13:46, 12 February 2007 (UTC)

I would also agree with Poujeaux, as a nonexpert. This phrase is just impenetrable to someone who is not already conversant with evolution and genetics.--Filll 14:56, 12 February 2007 (UTC)

I note that the term "allele" was being explained, but never actually came up again until it was, er, defined again - might as well save it for later. Adam Cuerden talk 19:20, 12 February 2007 (UTC)
  • The main problems I see with the current intro are:
  • "usually measured in terms of the genes encoding them." - This clause is extremely unclear in the context of the newly-revised lead section. First, the antecedent of "them" is very unclear as the first section is currently written; few people will be able to guess that "characteristics" is the specific noun being referred to, because the first clause discusses so many nouns (like "generation" and "population"). This will need to be rephrased; my current thinking is to either expand the "genes" explanation to a full sentence, or try to merge it into the next sentence in a way that clarifies that characteristics are being discussed. The second problem is that I don't like the use of the word "measured" here, as it implies that only quantities or numbers are relevant to genes.
  • Why was all mention of natural selection removed from the lead section?! This would be exceedingly easy to add to the second sentence; even just "Through natural selection," at the start of the sentence would work.
  • "In doing so, they will pass more copies of these beneficial traits on to the next generation," - This is a good opportunity to mention genes again, briefly. Otherwise we'll only have mentioned them once, momentarily, at the start of the first sentence, which will make it difficult for readers to understand the significance of genes. A simple change like adding "as genes" to the end of this clause would thus greatly improve comprehension.
  • Why was the link to speciation removed?
  • Why was the link to common descent removed?! -Silence 23:56, 12 February 2007 (UTC)

“Species problem” and Original research (OR)

1) “Species problem”-I am unable to find the particular definition used in this article for the word “Species”. It should be included so as to differentiate the word microevolution from macroevolution.

2) Original research (OR) - I am also unable to find the particular reference for the following statements: 

“Evolution is also frequently misinterpreted as stating that humans evolved from monkeys”
Well, I think you are correct to ask for a citation but that will be an interesting one to get. However, I don't think it is OR. I mean this is simply overwhelming. For instance, a simple googling gives me this site which is so sad it's true 8(((( [1] Candy 21:28, 12 February 2007 (UTC)


Hi Candy,Thanks, you are correct; I think it is a NPOV omission.I wasn't able to find anything about monkeys at [2] (I did however find allot of expletives and emotional outbursts.) HFAS 00:06, 13 February 2007 (UTC)


“It is also frequently claimed that speciation has only been inferred, never directly observed.”

HFAS 20:31, 12 February 2007 (UTC)

Baraminology

If anyone cares, have a look at Wikipedia:Articles_for_deletion/Baraminology. Adam Cuerden talk 21:45, 12 February 2007 (UTC)

Awkward English

The first sentence:

In biology, evolution is the change from generation to generation in how common various inherited characteristics are within a population, usually measured in terms of the genes encoding them.

suffers from some awkward English.--Filll 00:04, 13 February 2007 (UTC)

Could you be a little more specific? -Silence 00:19, 13 February 2007 (UTC)

Well here are a few comments:

  • I think the sentence is too long and should be broken into two sentences.
  • The phrase "change in how common" seems a bit clumsy to me. I would use something like "change in characteristics" or "change in features" and forget the common part or frequencies etc.
  • The expression "genes encoding them" is a bit much for a beginner.

I can give more feedback.--Filll 00:24, 13 February 2007 (UTC)

Yes, Filll, this is still unclear, or at least causes the reader to stumble in the very first sentence, which is a shame. The difficulty is with 'in how common various inherited characteristics are'. One solution is to drop the 'how common' part as you suggest, In biology, evolution is the change from generation to generation in various inherited characteristics within a population, usually measured in terms of the genes encoding them. This is much more readable but I expect some will object to the oversimplification - it is really not the characteristics that are changing. Or we could go back to the version with "frequency"! Sorry, I see silence has done something like this. The lead is now excellent I think! Poujeaux 13:45, 13 February 2007 (UTC)
Actually, it is the characteristics that are changing, at least in a sense. "Change in frequency of a characteristic" is a type of "change in a characteristic", from the perspective of change in organisms. If there is concern with such wording, it seems trivial to me. I simplified the wording in the first sentence; if anyone has any further suggestions, feel free to make more changes or comments. -Silence 15:01, 13 February 2007 (UTC)

FYI

I am unclear exactly where in Wikipedia this should be dealt with, but I know the people who make such choices read this talk page. This New York Times article called Believing Scripture but Playing by Science’s Rules is worth reading for the issues and examples it raises (but not as a refutation of any part of science). One issue it raises is, Are you a scientist if you merely memorize the right things? Or is it more than that? Suppose you believe a 6,000 year old Earth yet write a science paper based on standard chronologies. Does your belief count agianst you? 4.250.177.25 00:58, 13 February 2007 (UTC) (WAS 4.250)

  • Please sign up and become a member of the community. It makes it easier to speak with you! I liked the example of being a socialist studying economics in a supply-side environment. What better way to understand the other side? Of course, as a liberal Democrat, I would never study politics at the Heritage Institute. But I'm too old to worry about such things. Anyways, I guess I admire the kid for setting aside his biases to get his geology degree. And he went on to teach at a Christian University. I have no problem with it, though if he publishes anything (even in the area of evolution or plate tectonics), I'd be a bit suspicious. What if he wrote something that could be disproven and then used by a YEC to say "see these evolutionists (sic) don't know what they're talking about." Otherwise, it's not a big deal. Orangemarlin 01:30, 13 February 2007 (UTC)
The appropiate page is Creation-evolution controversy. --Michael Johnson 01:38, 13 February 2007 (UTC)

Odd sentence in lead

"Minor random changes in the genes that encode these characteristics, or traits, cause organisms to have slightly different traits than their parents."

This is obviously about mutations, but it's awkwardly placed, without a brief overview of genes and heredity to put it in context, and ignores other important sources of variation, particularly the simple reshuffling of sexual reproduction. It's a good sentence in isolation, but not where it is. Adam Cuerden talk 01:08, 13 February 2007 (UTC)

The first sentence (as well as this one) explains heredity ("inherited characteristics"), and this section explains genes. What more context is needed? And why need this section only be about mutations; are the changes involved in genetic recombination not "minor"? Are they not "random"? This sentence is needed in the lead to explain that parents and offspring differ (which is what allows for variation, and thus for natural selection, which is covered in the next few sentences after this one); we've removed all references to the specific mechanisms that produce variation, so we need something like this at the very least to make up for that. -Silence 04:19, 13 February 2007 (UTC)

Actually, genetic recombination is a random, but complete reshuffling. It wouldn't resemble either parent. Perhaps we should re-add mechanisms of variation? Adam Cuerden talk 14:04, 13 February 2007 (UTC)

No, we shouldn't. Mechanisms of variation are discussed immediately below the lead section. I still don't see any problems with the current wording; could you be clearer about your concerns with this sentence? What makes it "odd"? What makes it "awkward", or ambiguous, or inappropriate, in the context it's in? I don't understand what you mean, either, by "It's a good sentence in isolation". -Silence 14:57, 13 February 2007 (UTC)

Just coming back to this after a few days absence. Here's my take on the latest lead:

  • I like the first sentence though I personally prefer direct use of the word 'traits'. My only real objection here is the word 'various' which suggests to me some traits are 'part of' evolution whereas others are not. It makes me ask which are the various traits we are talking about?
  • I think the first paragraph generally does not make clear enough distinction between the fact of evolution and the mechanisms that cause it. Natural selection is given too much emphasis here for my liking (whereas drift is completely omitted).
  • 'Minor random changes in the genes that encode these characteristics, or traits, cause organisms to have slightly different traits than their parents' . I think this is basically false (at least it's not the main cause). Organisms have different traits from parents even without any mutation.
  • Later in the article what is the difference between 'basic process' and 'mechanism'. This does not seem to make any sense to me. Why for example is mutation refered to as a 'basic process', but natural selection a 'mechanism'? Furthermore how is 'variation' a basic process that is distinct from mutation (and recombination)??
  • I also have a problem with 'recombination'. This is not a mechanism that causes evolution in its own right: crossing over may change gene distribution but not gene frequency (which is how evolution is defined here). Any change to gene frequency that does occur as part of this process falls under natural selection, genetic drift or mutation.

— Axel147 17:33, 13 February 2007 (UTC)

  • I agree that we should simply use the word "trait" from the beginning, and not bother with "characteristics" at all. It's a common word (more so than many of the other words in the lead section), and it's wikilinked anyway. However, our view seems to be in the minority, unfortunately. I also tried removing "various" from the first sentence for the sake of simplicity.
  • "Natural selection is given too much emphasis here for my liking (whereas drift is completely omitted)." - It is my opinion that natural selection is much more important to explain to people completely unfamiliar with evolution than drift is. It is more complex, more important and essential for understanding the diversity and history of life, and easier to explain without going into technical details and opaque genetic terminology. We can (and do) explain these two mechanisms side-by-side in the sections immediately following the lead, but I feel that we should focus on natural selection for the lead itself, if only for the sake of keeping the explanation coherent and accessible for uninformed readers.
  • "Organisms have different traits from parents even without any mutation. " - Where does the sentence mention mutation?
True, it doesn't but like Adam Cuerden I interpreted it this way. — Axel147 20:34, 13 February 2007 (UTC)
  • "Why for example is mutation refered to as a 'basic process', but natural selection a 'mechanism'?" - I have absolutely no idea. I assumed whoever organized the article in that way knew what he or she was talking about. -Silence 19:37, 13 February 2007 (UTC)
You're saying miinor random changes in the genes - this can only refer to changes in the genes themselves as individuals,, e.g. mutations, with that phrasing, but without any other context to clarify that there's other sources of variation, it's misleading. That said, Natural selection is the key mechanism - genetic drift is random changes. It shouldn't be too hard to fit in genetic drift by emphasising the random component, but I don't think any article on Evolution could justify not having a good-quality explanation of natural selection. Adam Cuerden talk 20:18, 13 February 2007 (UTC)
I agree that a good explanation of natural selection is necessary in the article but think for the lead paragraph just to mention natural selection as an important mechanism of evolution is enough. — Axel147 20:34, 13 February 2007 (UTC)
Eh, I think it works better as one paragraph than the old two paragraphs - we can't presume knowledge of natural selection, so we'd just end up explaining it twice anyway... Adam Cuerden talk 20:43, 13 February 2007 (UTC)
Er, it isn't one paragraph and I see no reason to explain it twice. It's currently re-explained in the 'mechanisms of evolution: selection' section. In my humble opinion the opening paragraph should explain evolution not natural selection. — Axel147 23:41, 13 February 2007 (UTC)

Just to broaden this ... surely there should be a "may" in here? A change in a gene does not necessarily cause a change in a trait. Candy 00:33, 14 February 2007 (UTC)

Well yes. (Putting my pedantic hat on I was wondering whether the absence of 'may' is defensible in the same way it's ok to say 'smoking causes cancer' i.e. causality is understood probabilistically: the cause does not necessairily lead to the effect in every case.) Anyway, I think you agree with me that words like 'frequency' shouldn't be too difficult for the average reader, but what's your take on the rest... — Axel147 14:08, 14 February 2007 (UTC)
Natural selection used to be in both the first and second lead paragraph, which confused me as to what you referred. However, given natural selection is the major force in most of the major observable changes of evolution on the large scale, I don't think we can, with justice to evolution, pretend it's not important enough for the lead. Adam Cuerden talk 16:14, 14 February 2007 (UTC)
Unfortunately it is not so straightforward. It may be correct to say natural selection is the major force behind adaptive evolution but not necessarily evolution per se. I quote from The Nature of Selection by Elliott Sober to illustrate this point:
'When traits differ in fitness in a finite population, there is no way to make sense of the idea that selection has been more influential than drift in producing a particular evolutionary result. ... If drift is an evolutionary force it is a force of a different color.'
The best we can do is say genetic drift is important at low population size whereas natural selection becomes increasingly important with a large population. — Axel147 19:07, 14 February 2007 (UTC)
Yes, however, at higher levels - speciation and genus divisions, natural selection becomes dominant in having caused the changes, after a certain small amount of random chance (genetic drift) started them on different paths. Major changes to body plan are always going to be natural-selection regulated, even if triggered by initial variation due, in part, to genetic drift and other random-chance factors like the founder effect. It is at this level where almost all the misunderstanding of evolution happens, and so it is quite right to explain the part most people misunderstand, while the refinements of pointing out the exact role of random chance should not be excluded (we need to add it in a bit more than it is, I think), but need not be particularly detailed, and, indeed, emphasising it too much feeds into the major misunderstandings of evolution. Adam Cuerden talk 21:02, 14 February 2007 (UTC)
Have tweaked it so that genetic drift is more explicitly implied, though the term itself is left off. Mentioned the initial source of variation, mutation, as such, left out the ways it moves between populations, like gene flow or HGT, as it's always going to have an initial source in mutation. Adam Cuerden talk 21:22, 14 February 2007 (UTC)


No, I don't think you have got this right. It is wrong suggest random factors play a role in the beginning and then natural selection takes over afterwards. Each and every selection 'event' has a random component. It is true that 'major changes to body are always going to be subject to natural selection'. This is true wherever there are fitness differences, but it does not mean the fittest option is always going to win out. Chance (drift) acts simultaneously with natural selection at all stages. — Axel147 00:04, 15 February 2007 (UTC)

I am quite aware of this: That's why I've carefully emphasised that it's only a general trend in every sentence of the Natural selection description. 01:24, 15 February 2007 (UTC)

Predictive powers?

The synopsis talks about the predictive power of the evolution theory. Mandelian inheritance and now genes explain the inheritance of phenotypic traits. For all its merits, I can't see what is the predictive power of the evolution theory.

In a time where evolution theory is violentlyy criticized, this is particulary stupid to claim as real imaginary properties of that theory.

Spayrard 18:46, 14 February 2007 (UTC)

Evolution is visible within human timeframes among species that reproduce very rapidly (minutes to hours). For example, if you create a new antibiotic that works great with existing strains of a particular bacteria, evolution predicts that new strains of the bacteria will evolve which are resistant to the drug. We can see this prediction come true within a human lifetime.
As another example, evolution also successfuly predicts that if you find fossils of two similar species that date to a particular era, you're likely to find fossils of an older species that is similar to both of the two newer species.
As another example, evolution also successfully predicts that you're unlikely to find fossils of a newer species among fossils of various species that went extinct longer ago.
It's completely meaningful to talk about the predictive power of evolution. MrRedact 19:27, 14 February 2007 (UTC)
Tiktaalik .... :) .. dave souza, talk 20:01, 14 February 2007 (UTC)


I would prefer to say it is falsifiable in the sense given by Popper.Predictive power sounds to strong. What is predicted is strong enough to be falsifiable but otherwise pretty weak. Anyway the article must justify to claim. One should be able to search the article for the expression predictive power and find justification of that claim. The examples given by MrRedact show perfectly the theory is falsifiable. Someone must be able to search for the work predictive power

. Spayrard 16:13, 17 February 2007 (UTC)

The article predictive power defines it mostly as falsifiability. I assume it meant something stronger like something well defined will happen at well defined place and well defined time. So I rest my case on this point even if I would prefer the word falsifiability. I maintain the claim has to be justified within the article and easily searcheable. Spayrard 16:21, 17 February 2007 (UTC)
The word falsifiability would be inappropriate here because falsifiability is a necessary prerequisite for a scientific theory; therefore to say that evolution is "falsifiable" (or, worse yet, "very falsifiable") would be entirely redundant. It would be like saying "Evolution is parsimonious" or "Evolution is methodologically naturalistic". That evolution has predictive power conveys the fact that it is falsifiable clearly, but more importantly notes that evolution's predictions are extremely fundamental and wide-spanning, and thus have more "power" for predicting phenomena than the overwhelming majority of scientific theories. In other words, evolution's predictive power is not merely its falsifiability, but its utility for making predictions (like "bacteria will tend to develop antibacterial immunities if exposed to them long enough"). -Silence 16:34, 17 February 2007 (UTC)
I think that evolution has plenty of predictive power and makes lots of predictions (although some might be called postdictions). Prediction is different than falsifiability, although clearly related.--Filll 17:49, 17 February 2007 (UTC)
The predictive power of evolution is directly linked to research in molecular genetics, bacterial growth studies, immunology, and on and on (do a quick Google Scholar search and see for yourself - these fields are brimming with exciting research). Aside from the common ancestor axiom of the theory, the other axioms of evolution - if you take a careful moment to consider them from the standpoint of science (not as someone taking a position in a debate) - clearly have great merit in current and future hard scientific research. Major alterations of this section of this article would therefore not make sense. Astrobayes 21:17, 19 February 2007 (UTC)

"Macro" and "micro"

I am surprised that the article uses the terms "micro evolution" and "macro evolution." I thought those were invented by people who seek to discredit the theory. Are there any accredited biologists who use the terms? A reference would be welcome. Jive Dadson 05:56, 15 February 2007 (UTC)

Yes they are used by biologists, but not always in a consistent fashion or meaning the same thing. One well respected example textbook that uses the terms is Carroll's Patterns and Processes of Vertebrate Evolution. JoshuaZ 06:04, 15 February 2007 (UTC)

Archiving proposal

This Talk page is now up to 223 Kb, which is huge. How about I archive items 1 through 19 ('Phenotypic plasticity' through 'FA removed'). See Table of Contents for the numbering. That will leave items 20 through 35 in place, some of them very long, but many are still quite active topics. If you have concerns about this move, please respond. EdJohnston 19:16, 15 February 2007 (UTC)

Small change to intro paragraph

I would like to edit one sentence for clarity: "Given enough time, this passive process result in varied adaptations to changing environmental conditions." would, I think, read better as "Over time, this process results in varied adaptations to changing environmental conditions." 66.192.94.185 21:09, 15 February 2007 (UTC)

I also have a suggestion. I agree that "Minor random changes" does produce speciation, but this ignores aneuploidy and ploidy where gene and chromosome dosage appears to play a role. Given the emphasis on polymorphisms later it seems reasonable to mention duplication events. While the genetic change at even given locus is random the loci are not random. Every genome sequenced to date indicates that evolution occurs in hot spots and some of the genome is immune to any changes. Ernst Mayr never believed that Kimura was correct with Neutral molecular evolution and in his last book before his death never even breached the subject (but that is POV). Also environmental induced mutagenesis is well recognized, so no changes without environmental stress or change. I'd just say "Random changes" because not all changes are minor. Of course there are examples of minor changes with speciation, but for NPOV I don't think you can say that with impunity. GetAgrippa 14:54, 16 February 2007 (UTC)
Hmm. I've never liked either of those sentences anyway. Go for it. Adam Cuerden talk 00:38, 17 February 2007 (UTC)
Gave it a go. Minor tweaks. Does it read better?? I thought the anonymous suggestion was good so I added it too. Anyways the article is really tight and the intro is a good synopsis for a quick read. I think adding on to the history section was a good suggestion by Silence. The whole article is much more manageable. GetAgrippa 03:20, 17 February 2007 (UTC)
"Minor changes" is limiting. "Alterations" in gene would include epigenetic change which is not a direct change in the gene but methylation or RNA directed gene silencing. GetAgrippa 04:00, 17 February 2007 (UTC)
Thanks for adding my anon suggestion (I have a username now :-). Now it looks much better, but I noticed a typo in the second sentence: "Minor random changes in the genes that encode these traits, produces new traits..." The subject is plural ('changes') but the verb ('produces') isn't. I would fix that myself but I can't find the edit button.SheffieldSteel 03:52, 17 February 2007 (UTC)

I think another good suggestion that was gaining momentum was removing the Misunderstandings section and addressing each topic as needed in the text. I thought that was a good idea too. GetAgrippa 03:24, 17 February 2007 (UTC)

On minor changes vs. alterations: I find alterations to be far more confusing: It's just too broad of a term. I think we're probably best to bring in the other major methods of adding new traits - gene duplication, etc, later, and just be careful not to say that anything is an exclusive cause. (Mind you, this is probably moot since the bit about speciation is now clearly written to have a disjunct with what's before.) Adam Cuerden talk 00:27, 18 February 2007 (UTC)

  1. ^ Stephen J. Gould (1997-06-12). "Darwinian Fundamentalism". New York Review of Books. Retrieved 2006-08-01.
  2. ^ Paleontologist Stephen Jay Gould once summarized this as "variation proposes and selection disposes". Stephen J. Gould (1997-06-12). "Darwinian Fundamentalism". New York Review of Books. Retrieved 2006-08-01.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Talk:Evolution/Archive_32&oldid=390311992"