Talk:Evolution/Archive 45

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re: wording on Natural selection

the current text 'Natural selection is a process that causes heritable traits that are helpful...' implies that natural selection is *causative* ("sulfuric acid *causes* acid burns"), which it is not. It is *consequential*, eg: as a result of mutation in some gene, individual X died during gestation. Natural selection did not cause that death, it was caused by a deleterious mutation; accordingly, the *consequence* was natural selection.

furthermore i feel it is important to stress that the distinction between individuals and populations.

Hence I would argue that my edit is valid, as you apparently missed the significance of my edit. here is the text I contributed:

'Natural selection describes the tendency of heritable traits that are helpful for the survival and reproduction of individuals to become more common in a population, and harmful traits to become more rare.'

note the removal of a) causation ascribed to NS, and (b) clarification of individual v population Mjharrison (talk) 11:22, 16 January 2008 (UTC)

Frankly, this is not particularly compelling, and is pretty tortuous reasoning. Good heavens.--Filll (talk) 13:49, 16 January 2008 (UTC)

mjharrison, your proposed wording is difficult to read. First of all, tendency? That's a weasel word of the highest order. "Helpful" is pretty much the same. A quick read seems like Natural selection may or may be something. And I'm not sure I agree with your causative statement. Natural selection does force helpful traits to increase in frequency in the population, and for harmful traits to become rare. If it doesn't do it, what does? Intelligent design? That's why we have to be clear. OrangeMarlin ^{Talk• Contributions} 15:48, 16 January 2008 (UTC)

I think he has a point (that mutation creates new traits, and natural selection filters out the bad ones, as opposed to "causing" them), but his suggested alternative is not very good. Raul654 (talk) 15:56, 16 January 2008 (UTC)

I tend to agree with Fill, and this posit seems to emphasize mutations and (hence mutationism) and limit natural selection. The Modern Synthesis emphasizes natual selection. Natural selection is the reproductive success of heritable traits. Natural selection is the process that "causes" certain heritable traits or mutations to become more common-I guess you could say "process whereby". Mutations can be persist for thousands of years in a population before natural selection acts to produce evolution-such as insecticide resistance in drosophila. The mutation didn't cause evolution-natural selection acts on mutations (variation) to produce evolution. Evolution can be a "consequence" of natural selection. GetAgrippa (talk) 15:57, 16 January 2008 (UTC)

Natural selection isn't a description of a tendency, it is a mechanism that produces this tendency. Tim Vickers (talk) 16:27, 16 January 2008 (UTC)

OK, ignoring the stylistic criticisms, which are of course purely subjective, and the notion that somehow a 3 clause sentence is "difficult to read" (!?), I'll re-address my principal concerns, which are semantic in nature (pun not intended). It is incorrect, from scientific POV, to describe NS as the _causative_ agent behind evolution. It's not. The _causative_ agent is the spontaneous mutation that occurs between generations of individuals, the _consequence_ of said mutations upon an individual or population in response to environmental stimuli is natural selection. Hence my proposed edit.

In any case, changing "the process that causes" to "the process whereby" would be an improvement. My preference for avoiding the term 'process' is part writing style, but conveys some semantic significance as well; that is that 'helpful' mutations are usually, but not always inherited/magnified within a population. Hence, 'tendency', but this is totally minor.

@GetAgrippa - your reply is littered with NS anthropomorphisms, which in a scientific article, to me, should be avoided as much as possible, and again: the causative agents of evolution are mutation and environmental circumstances, not natural selection per se.

@TimVickers, no the mechanism is spontaneous mutation. natural selection is the result. Mjharrison (talk) 18:56, 16 January 2008 (UTC)

Not sure you can get consensus for your views. But thanks anyway.--Filll (talk) 19:09, 16 January 2008 (UTC)

There seems to be a bit of confusion. Mutation produces new alleles and then natural selection causes these alleles to become more or less common. Mutation does not change allele frequencies. The mechanism that changes allele frequencies is therefore natural selection, not mutation. Tim Vickers (talk) 19:14, 16 January 2008 (UTC)

I agree with Raul654. I think there has been some sloppy over-generalizations and mischaracterizations in this discussion, but there is one point that is important: that natural selection is non-teleological. It works by process of elimination - nature is not really selecting what is good (adaptive), it is selecting what is not adaptive and getting rid of it; whatever is left is defacto adaptive. This is not easy to express clearly because Western culture is so thoroughly imbued with a language of causation and teleology. i certainly agree with everyone that whatever we write, it must be clear and direct.

To respond more directly to this argument, i think people are speaking past one another. The issue is not whether the mechanism is mutation or natural selection, both are: Mjharrison is right that mutation is a mechanism - but not a mechanism of speciation, it is a mechanism that produces variation. Tim Vickers is right that natural selection is a mechanism, of speciation.

I do think that Mjharrison is quite wrong when s/he writes, "Natural selection did not cause that death, it was caused by a deleterious mutation." It is only because natural selection acted to eliminate onrganisms with mutation x so that the frequency of allele x decreases in the population over time that we conclude that mutation x was deleterious. Mjharrison writes as if mutations either are or are not, in some intrinsic way, deleterious, when in the Darwinian model they are not, what is deleterious is contingent on the environment i.d. nature. In this I think Tim, Fill, GetAgrippa, and others are right to take issue with Mjharrison.

But I do think that there is a valid point Mjharrison is raising. The key issue is not whether or not natural selection is a mechanism, but that it is a mechanism that works in a way unlike most other mechanisms people are familiar with. I can understand why someone might even take issue with the word mechanism because natural selection does not work like literal mechanisms, by which I mean machines, or if you prefer the "mechanics" that physicists study. If we call natural selection a mechanism, and someone thinks that because we call it a mechanism it operates (causes effects) in the same way that the forces physicists study, they would be wrong. I think Mjharrison is right that we should be careful somehow to communicate to readers that natural selection is utterly unlike these other mechanisms in that it is not a force in the same way that gravity, electromagnetic fields, or the weak or strong nuclear bonds can be described as forces. (I won't even bring up the debates over whether gravity is actually a "force" and one can actually speak of gravity as a "mechanism" - my point is just that I think when most people see the word "mechanism" they have a Newtonian notion of what the word means, and this is NOT what Darwin or contemporary biologists mean.)

Mutation is a mechanism that produces variation in alleles. Natural selection is a mechanism that involves all sorts of complex environmental interactions, that directly causes the decrease in frequency of certain alleles. It has as a byproduct or indirct effect the increase in frequency of other alleles, and that may result in speciation. Slrubenstein | Talk 19:44, 16 January 2008 (UTC)

Slr, you make a ton of sense. Natural selection is a force, made up of many different components (including I suppose random bad luck), that moves the genetic mix over time. But it isn't definable. There isn't a measurement for Natural selection (e.g., 10 mega-Rubensteins of Natural Selection will cause one new trait). It can't be measure, and that's what confuses the casual or even technical reader. OrangeMarlin ^{Talk• Contributions} 23:30, 16 January 2008 (UTC)

Isn't the article pretty clear that NS is "caused" by other things (the whole "self-evident" paragraph)? Having made it clear that NS isn't a fundamental force, I think it's quite reasonable to say stuff like "natural selection causes...." Gnixon (talk) 20:12, 16 January 2008 (UTC)

Nothing I said humanizes natural selection or evolution???? MjHarrison what your are proposing sounds like Mutationism as held by Morgan and Nei. Natural selection is differential reproductive success. Mutation provides variation but doesn't cause evolution-are you implying that all mutations cause evolution? I would agree that mutations drive evolution. As I mentioned the mutation associated with insectide resistance is believed to be 80,000 years old and the evolution by natural selection (shift in gene alleles) has only occured the last 100-200 years. I think Slrubenstein is correct in our failure to communicateGetAgrippa (talk) 23:55, 16 January 2008 (UTC)

As an amateur I liked MjHarrison's shift of emphasis away from "causes" and focus on the effect working on individuals, and hence the population. Tim Vickers has mentioned the individual in the following sentence which probably suffices, and I'd suggest getting away from the "causes" thus – "Natural selection is a process in which heritable traits that are helpful for survival and reproduction become more common in a population, and harmful traits become more rare. This occurs because individuals with advantageous traits pass on more copies of these heritable traits to the next generation." The bit that's missing is the source of the traits, and "mutation" has the unfortunate implication for the layman of "hopeful monsters", dramatic changes suddenly arising and taking over. My understanding from peppered moth evolution is that no mutation is needed, the traits could always have been there, but the change in environment and resultant success of bird predation led to a change in the frequency of traits. How about preliminary sentences on the lines of "All living organisms have offspring which show minor variations. Where these variations can be passed on to future generations they are called heritable traits." followed by the sentences under discussion. ... dave souza, talk 00:23, 17 January 2008 (UTC)

But isn't any trait a result of a mutation, whether in the last generation or 1 million generations ago? OrangeMarlin ^{Talk• Contributions} 01:21, 17 January 2008 (UTC)

Epigenetic phenotypes (traits) are possible from environmental cues with no change in genotype. Some epigenetic phenotypes are heritable for several generations. Further some authors suggest this as a possible means of evolution with the trait being immortalized later by a mutation. I have provided some of those odd papers in the past. You can still argue they are epialleles and epimutations however. GetAgrippa (talk) 02:15, 17 January 2008 (UTC)

They're heritable? Are there any common examples, or is this so rare that it is almost an undue weight issue? I still contend that phenotypes require a genotype, which results from random mutations. The environmental cues may just cause a phenotype to be expressed. I'm getting a headache thinking about this. No wonder natural selection is so difficult to explain. OrangeMarlin ^{Talk• Contributions} 09:57, 17 January 2008 (UTC)

There is a significant literature about environment induced epigenetic phenotypes (that are not genotypes) in animals (from rotifers to birds to lizards to insects) and also in plants. There are some examples of heritable epigenetic states, and few link all this to evolution. All the epigenetics is proving a new realm to explore, and I think it significant because the role it appears to play in the germ line (hence evo potential). I think it is interesting because we often use phenotype as the end measure especially breeders, but population geneticist really focus on the genotype. It would be "undue" to mention this for this article. GetAgrippa (talk) 14:11, 17 January 2008 (UTC)

Agree, they are heritable, especially in plants, usually as a chromosomal imprinting. Mutations of this type are known as epialleles and are metastable. David D. (Talk) 22:01, 17 January 2008 (UTC)

Man, I'm not getting this. I'm going to have to read more, since it still sounds like the this is an even more direct "force" on the genotype, in that a mutation will eventually show up. I'm really confused, and I thought I understood this. Maybe if I drink heavily it'll break through to my brain. OrangeMarlin ^Talk•

Hey Orange here are some interesting articles concerning mutation-epimutations, and some on where the focus of evolutionary thought should be:

Godfrey KM, Lillycrop KA, Burdge GC, Gluckman PD, Hanson MA. Epigenetic mechanisms and the mismatch concept of the developmental origins of health and disease. Pediatr Res. 2007 May;61(5 Pt 2):5R-10R. Review. PMID: 17413851 [PubMed - indexed for MEDLINE]

Agrawal AA. Phenotypic plasticity in the interactions and evolution of species. Science. 2001 Oct 12;294(5541):321-6. Review. PMID: 11598291 [PubMed - indexed for MEDLINE]

Galhardo RS, Hastings PJ, Rosenberg SM. Mutation as a stress response and the regulation of evolvability. Crit Rev Biochem Mol Biol. 2007 Sep-Oct;42(5):399-435. Review. PMID: 17917874 [PubMed - indexed for MEDLINE]

Pigliucci M. Is evolvability evolvable? Nat Rev Genet. 2008 Jan;9(1):75-82. PMID: 18059367 [PubMed - indexed for MEDLINE

Pigliucci M. Do we need an extended evolutionary synthesis? Evolution Int J Org Evolution. 2007 Dec;61(12):2743-9. Epub 2007 Oct 9. PMID: 17924956 [PubMed - in process]

Hendrikse JL, Parsons TE, Hallgrímsson B. Evolvability as the proper focus of evolutionary developmental biology. Evol Dev. 2007 Jul-Aug;9(4):393-401. Review. PMID: 17651363 [PubMed - indexed for MEDLINE]

Sorry for the long list. GetAgrippa (talk) 14:02, 18 January 2008 (UTC)

Contributions 06:15, 18 January 2008 (UTC)

Epigenetics is a whole subject (and a newish one). Evolution needs to mention it but not go overboard as Evolution is already pretty long (perhaps too long). I suggest that:

The intro should mention it as one possible source of the variation on which natural selection acts.
A later section should outline epigenetics brieflyand link to Epigenetics. This section should point out that "epigenetic" in the general sense refers to any environmentally indiced change in genses (see for example The necessity of a human epigenome project, which talks mainly about cancers) but that the sense that's important for evolution is hereditable genetic change (don't know whether we should mention the Central dogma here). Philcha (talk) 14:49, 19 January 2008 (UTC)

Yes, but the first paragraph already states that mutations can produce new traits. Surely we don't need to repeat it in the next paragraph. Sheep81 (talk) 01:25, 17 January 2008 (UTC)

Good point. My concern is just that "mutations" sound to the layman rather dramatic, ape giving birth to a human etc.. In dog breeding, each generation could be selected for shorter legs and other factors, until the dachshund has been bred. Is each generation a mutation? .. dave souza, talk 22:28, 17 January 2008 (UTC)

No, mutation is the appearance of a new or non-normal allele ("value") of a gene ("variable") - I said "or non-normal" because some apparently appear repeatedly, e.g. it is generally thought that the UK's Queen Victoria did not inherit the hemophilia allele from either parent but it appeared spontaneously in her and spread throughout the royal families of Europe by intermarriage. Dog breeding is artificial selection by deliberate human action, and works by increasing the frequencies of the desired alleles in the breeding group and / or by eliminating undesired alleles (but dog breeders don't think in terms of genes, only of desirable / undesirable traits). Hope that helps.

Re "mutations' sound to the layman rather dramatic ...", that's a fair point, which the article should clear up. Generally the more dramatic mutations will be unviable and, in placentals mammals including humans, will usually be spontaneously aborted (can't remember the incidence of this in humans but it's surprisingly high; most mothers are unaware of it because such embryos usually abort before symptoms of pregnancy appear). Viable mutations are rare and small, which is why evolution is so slow by human standards. Philcha (talk) 14:49, 19 January 2008 (UTC)

Thanks, that helps. So a mutation in Queen Victoria led to Czar Nicky's son having haemophilia, hence Rasputin and the Russian revolution ;) It's a complex idea, as the peppered moth evolution in the 20th century was to do with the frequency of a mutation / morph that had first appeared early in the 18th century, a black and white situation so to speak. Presumably the shifts in beak shapes in Darwin's finches as studied recently involve a repeated small mutations affecting control or timing of beak growth. It's actually quite hard to me to think of such a small change being a mutation, but guess so. The clarification is greatly welcomed. .. dave souza, talk 23:08, 19 January 2008 (UTC)

The beak in Darwin's finches is formed under the influence of cranial neural crest and bone morphogenetic protein but the key regulator I believe is in calmodulin gene expression, hence is indirect by cell signalling. What change produces the alteration in gene expression I don't know, but no mutation in calmodulin has been reported-just other proteins?? Even artificially manipulating calmodulin expression would alter beak morphology in predictable ways. Character displacement occurs in Darwin's finches so the beak can respond and change shape in response to competition relatively quickly-in decades. I gather this is epigenetic as the trait can wax and wane. In development, timing is everything so alterations in gene expression are just as powerful as a mutation in the gene sequence of a protein. GetAgrippa (talk) 00:27, 20 January 2008 (UTC)

Acting at the level of the individual is an opinion and dependent on who you ask as you can also get pop, deme, gene,etc. as an answer. I note the Population genetics article states population geneticists measure the distribution and shifts in alleles in a population under the influence of the four evolutionary "forces": natural selection, genetic drift, mutation and gene flow. Interesting word choice. Slrubenstein you are correct about "mechanism" it is a poor word choice because we mean it in a "how" sense. Most people associate mechanism as a "device" and cause effect sense. Force seems very descriptive and applicable. GetAgrippa (talk) 04:01, 17 January 2008 (UTC)

Mutation is wikilinked, laymen can click on it to see what it means in this context, or they can read about in the shorter Mutation section of this article. I don't think we should hold back using basic terminology because it might be misunderstood... rather we should use the terms and make sure to explain them properly. Sheep81 (talk) 02:16, 18 January 2008 (UTC)

The first paragraph also gives credit to gene transfer for the introduction of new traits, so it's not just mutation that we are citing, if that's an issue. In the case of dachschunds, genes from another, possibly only distantly-related, dog with short legs would be introduced into a particular bloodline, adding new short-leg genes to the genome in that line so that the offspring have even shorter legs. But those genes weren't the result of a mutation in that generation... they already existed, just not in that bloodline. That's basically gene transfer, right? Sheep81 (talk) 02:28, 18 January 2008 (UTC)

All this conversation does get me wondering should we add a paragraph to the mutation section on how mutations translate into change and evolution. Some mutations appear fairly direct and others influence global modulator proteins like calmodulin mutations and beak formation in Darwin's finches. We could use several examples of mutations and associated change in bacteria, birds, etc. Maybe some kind of analogy like mutations are clay and selection and drift mold the clay-poor one but you get the idea. Just an idea. I also keep reading about this concept of "evolvability". This maybe more suited for the Modern Synthesis article. GetAgrippa (talk) 14:03, 19 January 2008 (UTC)

Introduction to Evolution

I can't help but notice that this page is not riddled with allegations that you have exceeded the level of your audience. Could that be because (at your request) an Introduction to Evolution entry was created? Of course, being charged with such a task, I felt a need, no, an obsession to make it FA as to be worthy of companionship. Now as I am roasting over the fire of the FA process I can't help but be a little bit bitter. This is an FA in which the entire discussion page is a damning statement of ownership allegations. Ironic, considering my complete lack of confidence in my own knowledge and skills. I've been told with absolute confidence it will not make FA. If it doesn't it is not because of ownership or lack of constant pleas for assistance posted on this page. How hard would it be, to take a moment from your intellectual discourse; go next door and correct any problems. I am not seeking any more reasons as to why it sucks. That's too easy. I asking you to edit out any problems you see. The only constraint to the edits is to remember why it was written ... that being to target a younger, less informed audience. --Random Replicator (talk) 17:29, 19 January 2008 (UTC)

Good Golly you poor man. How many times have you changed referencing format and addressed cope-edit issues of various editors. This could go on ad infinitum (it reminds of a writing a dissertation and trying to coax a half dozen committee members to agree on style and prose). I am at a loss of the status of the article for support or oppose??? GetAgrippa (talk) 19:07, 19 January 2008 (UTC)

Just read the Intro article and I overall like it. I think some of the info would do well to be mentioned here. I would support making that article even more simple and moving some of the sections to this article-like a population genetics section. The Intro article touches on subjects (in some detail)that really should be mentioned here so that the Intro article would follow the Evo article outline but just more simple and a basic intro. I'll post my comments there too. Regards GetAgrippa (talk) 19:24, 19 January 2008 (UTC).

Intro too genetically oriented

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section.

I think the intro dives into genetics too quickly:

Darwin wrote The Origin of Species before anyone knew anything about genetics. He was trying to explain how one species develops from another. Darwin's concept was natural selection + inheritance with variation. He did not specify either the mechanism of inheritance or the causes of variation.
"One species developing from another" is how most people understand the term evolution, and why Creationists attack the concept. If the article starts too far away from "One species developing from another" it will lose readers in the first paragraph.
Other processes are involved, notably epigentic inheritance as discussed above and endosymbiosis as pointed out in an earlier Talk dscussion. Endosymbiosis is not limited to the origin of eukaryotes, for example it appears that the long pregnancies of placental mammals are possible only because of the action of retroviruses (Fox, D (1999), "Why we don't lay eggs", New Scientist); and on a slightly larger scale the guts of one termite species are a symbiosis theme park: the large amoeba Mixotricha paradoxa helps the termites to digest cellulose, and itself relies on attached symbiotic spirochaetes for movement and on endosymbiotic bacteria for important parts of its metabolism.

So I suggest the main elements of the article should be:

Evolution is the set of processes by which one species develops from another. There are 2 main sets of processes: those which produce innovations and those which prune them. N.B. at some stage knock on the head the old idea of a scala naturae with humans on the top rung.
Mechanisms which produce innovation: mutation, epigenetic inheritance, symbiosis, horizontal gene transfer.
Pruning mechanisms: natural selection, genetic drift.
Outcomes - as at present.
Evolutionary history of life - as at present.
History of evolutionary thought - as at present.
Social and cultural views - as at present.
Applications in technology - as at present.

That leaves the question of where to place most of the current genetics-based content. I suggest after "Evolutionary history of life", and / or move into other articles and cross-link. Philcha (talk) 14:54, 20 January 2008 (UTC)

Isn't this a Featured Article? I would think that it having gone through the "process" it is at a place of tweaking instead of major revisions-after all dozens of editors compromised and reached a consensus. I think you will find resistance to major revisions (even if I agree with some of your comments) after the "ordeal" of getting it to where it is at presently as a featured article. Regards GetAgrippa (talk) 15:10, 20 January 2008 (UTC)

Looking for definitions of "evolution" that are independent of this article I found:

"the sequence of events involved in the evolutionary development of a species or taxonomic group of organisms" WordNet.
""a) Change in the genetic composition of a population during successive generations, as a result of natural selection acting on the genetic variation among individuals, and resulting in the development of new species. (b) The historical development of a related group of organisms; phylogeny." Free Online Dictionary
"(a) The historical development of a biological group (as a race or species) (phylogeny) (b) A theory that the various types of animals and plants have their origin in other preexisting types and that the distinguishable differences are due to modifications in successive generations; also : the process described by this theory." Merriam-webster online.
"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)." [http://evolution.berkeley.edu/evosite/evo101/IIntro.shtml U of California Berkeley)
"In Darwinian terms a gradual change in phenotypic frequencies in a population that results in individuals with improved reproductive success." Northwestern U.
"Biological evolution ... embraces everything from slight changes in the proportion of different alleles within a population (such as those determining blood types) to the successive alterations that led from the earliest protoorganism to snails, bees, giraffes, and dandelions." Futuyma, D. J. in EVOLUTIONARY BIOLOGY, Sinauer Associates 1986
"‘Evolution’ in contemporary discussions denotes the theory of the change of organic species over time." Stanford Encyclopedia of Philosophy
"The origination of species conceived as a process of of development from earlier forms". Oxford English Dictionary.

So definitions that focus on how one species develops from another appear at least as common as those that are based on genetics. And, as I said above, Darwin started it all by analysing how one species develops from another, before Mendel empirically deduced the existence of genes and nearly 100 years before Watson & Crick discovered DNA. FA or not, Evolution starts off with a perspective that is both historically inaccurate and too narrow (the latter because there are non-genetic mechanisms such as endosymbiosis, and non-inheritance genetic mechanisms such as horizontal gene transfer). Philcha (talk) 16:44, 20 January 2008 (UTC)

Ah, I see you make reference to the conundrum I mentioned and that is how evolution theory has been based on phenotype but pop. geneticist focus on genotype. I think most evolutionary biologist would push for a gene-centric view as pop geneticist drive the science with testable models. The strict definition deals with shifts in gene allele frequencies, and comparative genomics is an interest and considered cladistically. I agree with TimVickers also with the outcomes and mechanisms. I mentioned an article above about the focus of evolutionary biology and should the Modern Synthesis continue and where should it go. Perhaps this discussion will help address some of these concerns many editors appear uncomfortable with. GetAgrippa (talk) 19:31, 20 January 2008 (UTC)

For people who want a gentler version of evolution, we have Introduction to evolution and the Simple Wikipedia article on evolution. However, this article has a different purview.--Filll (talk) 17:31, 20 January 2008 (UTC)

This difference in viewpoints probably comes from people either looking at the mechanism (allele frequencies), or the outcomes (adaptation and speciation). This article follows current theory on mechanism, which deals almost exclusively with allele frequencies. However, I'm still not 100% happy with how the lead explains the difference between outcomes and mechanisms - Philcha has a point here. Tim Vickers (talk) 17:37, 20 January 2008 (UTC)

I've made an addition to the first paragraph that might help with this. Tim Vickers (talk) 18:17, 20 January 2008 (UTC)

Thanks, Tim Vickers. I am aware of the modern synthesis, which was developed after Mendelian genetics but before the ideas of endosymbiosis or epigenetic inheritance. Modern evolutionary synthesis does not mention either of these. Evolution should also comment on e.g. the dual effect of mass extinctions (killing some, opening the door for others; dinosaurs and mammals both benefitted from this) and the importance at some points of ecological factors "opening doors" (Cambrian explosion is a possible example). The approach I proposed is more rigorous since it distinguishes clearly between requirements (variation and pruning) and the mechanisms that meet them (variation: mutation, endosymbiosis, epigenetic inheritance, horizontal gene transfer; pruning: natural selection, genetic drift); more comprehensive, since it recognises either sources of variation; and more adaptable, because new sources of variation and new pruning mechanisms can simply be slotted in. Philcha (talk) 18:50, 20 January 2008 (UTC)

To those concepts are already in the article, with endosymbiosis being a sub-set of gene flow and a form of horizontal gene transfer:

"The intermittent mass extinctions are also important, but instead of acting as a selective force, they drastically reduce diversity in a nonspecific manner and promote bursts of rapid evolution and speciation in survivors.[123]"
"Gene transfer has also occurred between the ancestors of eukaryotic cells and prokaryotes, during the acquisition of the chloroplast and mitochondrial.[76]"
"Soon after the emergence of these first multicellular organisms, a remarkable amount of biological diversity appeared over approximately 10 million years, in an event called the Cambrian explosion. Here, the majority of types of modern animals evolved, as well as unique lineages that subsequently became extinct.[149] Various triggers for the Cambrian explosion have been proposed, including the accumulation of oxygen in the atmosphere from photosynthesis.[150]"

Epigenetics used to be in the article, but was removed since its importance in evolution is currently unclear. Tim Vickers (talk) 19:28, 20 January 2008 (UTC)

User talk:TimVickers, Thanks for the note about epigenetics. I agree with all but 2 of your other comments. The items I'm unhappy with are "...with endosymbiosis being a sub-set of gene flow and a form of horizontal gene transfer" and your use of (quote from the article) "Gene transfer has also occurred between the ancestors of eukaryotic cells and prokaryotes, during the acquisition of the chloroplast and mitochondria." There is no intrinsic connection between endosymbiosis and gene flow / transfer. Transfers from mitochondrial to nuclear DNA are documented in various metazoa, but differ from one organism to another; which suggests that the transfers happened after and were made possible by the endosymbiosis but were not involved in the acquisition of mitochondria (Rate of Gene Transfer From Mitochondria to Nucleus: Effects of Cytoplasmic Inheritance System and Intensity of Intracellular Competition; Mitochondria evolved by endosymbiosis). Although the eucaryote nucleus may have been formed as a result of gene transfer following the earlier endosymbiosis of spirochetes within anerobic sulfidogenic archaebacteria, this was also probably a later development (The last eukaryotic common ancestor (LECA): Acquisition of cytoskeletal motility from aerotolerant spirochetes in the Proterozoic Eon). Gene transfer is involved in the endosymbiosis of the retroviruses that make placental mamamls possible, but that's an intrinsic feature of retroviruses rather than of endosymbiosis. I've found nothing to suggest gene transfer between the termite Mastotermes darwiniensis and its endosymbiont Mixotricha paradoxa; I wouldn't be surprised if there was gene transfer between Mixotricha paradoxa and its endosymbionts. In the other hand there appears to have been gene transfer to aphids from their endosymbiont bacteria (Associations, mergers and acquisitions in the biological world). And there is also evidence that endosymbiont bacteria (especially spirochetes) have simply lost some genes and rely on their hosts' pre-existing equipment for some metabolic functions. In short (?), many levels of gene transfer are possible in cases of endosymbiosis because there is no intrinsic connection. Hence endosymbiosis should be treated as a source of variation separate from genetic mechanisms. Philcha (talk) 20:39, 20 January 2008 (UTC)

I contributed to the Nucleus article section on nucleus evolution and not all the theories are endosymbiotic. I don't know about retroviruses and plancental mammals as even the fish Genus Poeciliopsis have also evolved a placenta, of course parallel evolution doesn't have to have parallel mechanisms. It is interesting how organisms have incorporated parts of their environment-pigments (flamingos), toxins, structures like nematocyst (nudibranchs), etc. from ingestion or other means too. Getting off topic. sorry. GetAgrippa (talk) 21:37, 20 January 2008 (UTC)

The mitochondrial genome is part of the complement of an eukaryote's genetic material, therefore the acquisition of this organelle added novel inherited traits to eukaryotes - it caused the transfer of genes from two ancestral organisms to one progeny organism. The only alternative to classifying organelle endosymbiosis as a form of gene transfer would be having a situation where we would have to consider the mitochondria and chloroplasts as organisms, which is not correct. Where the two organisms have not formed such an intimate association, such as between plants and root mycorrhiza, these interactions are a form of co-operation - an adaptation. Tim Vickers (talk) 23:07, 20 January 2008 (UTC)

"it caused the transfer of genes from two ancestral organisms to one progeny organism" - eventually, yes. But IIRC initially there would have been 2 distinct organisms in some sort of relationship which developed into symbiosis, then co-ordinated reproduction, then inter-dependence which may have been either mediated by or followed by gene transfer. And the initial relationship probably varied: spirochetes (the ancestral microtubules in Margolis' version) will form symbiotic relationships with almost anything that will have them (the little tarts); the aerobic bacteria that were the ancestors of mitochondria probably tried to prey on / parasitise an archean buit were neutralised; the photosynthesising bacteria that became chromoplasts were probably prey of an archean but managed to resist ingestion. In all of these scenarios some sort of "accommodation" would have preceded gene transfer - except transfer by viruses, plasmids and the other means of gene-swapping that microorganisms routinely use.

In any case the proposition that endosymbiosis is separate from gene transfer does not rest solely on the evolution of eucaryotes, as illustrated by the cellulose-digesting endosymbionts of termites and the photosynthesising endosymbionts of many marine invertebrates.

As far as I can see, the idea that endosymbiosis is a sub-set of gene tranfer implies that all cases of endosymbiosis necessarily involve gene transfer at a very early stage in the relationship, and I don't see how that could be proved. Philcha (talk) 00:28, 21 January 2008 (UTC)

All cases of endosymbiosis are adaptations driven by a natural selection since they confer a selective advantage. At early time-points this would be mutualism, then a symbiotic relationship, and finally irreversible endosymbiosis. Only at the final point, where a single organism is produced and gene transfer has taken place, is any force apart from natural selection producing changes in the hereditable characteristics of the organisms involved. I feel that to argue that endosymbiosis is a cause of evolution is to mis-assign a secondary consequence (an adaptation) as a causal factor. Tim Vickers (talk) 02:00, 21 January 2008 (UTC)

I like that description of endosymbiosis a lot better. But I was arguing that endosymbiosis is a source of variation in its own right, independent of genetic mechanisms. I think whether endosymbiosis is a cause of evolution is a different question. In fact if I understand Darwin's idea correctly evolution requires two types of causal mechanisms, at least 1 source of variation and at least 1 pruning mechanism. I think one could even argue that the continued existence of mutation, the "classic" source of variation, is a consequence of natural selection, because it didn't pay organisms to increase their investment in hi-fi reproduction any further, despite the fact that mutations are more likely to be harmful than beneficial (Mutation rates: When the going gets tough, beneficial mutations get going and Two-step Process Filters Evolution Of Genes Of Human And Chimpanzee comment on the beneficial:harmful ratio). Philcha (talk) 09:43, 21 January 2008 (UTC)

Sex evolved, behaviors evolved, etc. Evolvability evolved. Here is an abstract from Nei that I am sure I have posted before because I think he is so unique (so not really for the article) but he does give one pause to re-think natural selections influence: "Charles Darwin proposed that evolution occurs primarily by natural selection, but this view has been controversial from the beginning. Two of the major opposing views have been mutationism and neutralism. Early molecular studies suggested that most amino acid substitutions in proteins are neutral or nearly neutral and the functional change of proteins occurs by a few key amino acid substitutions. This suggestion generated an intense controversy over selectionism and neutralism. This controversy is partially caused by Kimura's definition of neutrality, which was too strict (|2Ns|< or =1). If we define neutral mutations as the mutations that do not change the function of gene products appreciably, many controversies disappear because slightly deleterious and slightly advantageous mutations are engulfed by neutral mutations. The ratio of the rate of nonsynonymous nucleotide substitution to that of synonymous substitution is a useful quantity to study positive Darwinian selection operating at highly variable genetic loci, but it does not necessarily detect adaptively important codons. Previously, multigene families were thought to evolve following the model of concerted evolution, but new evidence indicates that most of them evolve by a birth-and-death process of duplicate genes. It is now clear that most phenotypic characters or genetic systems such as the adaptive immune system in vertebrates are controlled by the interaction of a number of multigene families, which are often evolutionarily related and are subject to birth-and-death evolution. Therefore, it is important to study the mechanisms of gene family interaction for understanding phenotypic evolution. Because gene duplication occurs more or less at random, phenotypic evolution contains some fortuitous elements, though the environmental factors also play an important role. The randomness of phenotypic evolution is qualitatively different from allele frequency changes by random genetic drift. However, there is some similarity between phenotypic and molecular evolution with respect to functional or environmental constraints and evolutionary rate. It appears that mutation (including gene duplication and other DNA changes) is the driving force of evolution at both the genic and the phenotypic levels." He keeps beating this band wagon and he is getting it published, so more power to him. I have to admit I have become more "Neutral" in my thinking over the years. I should add that in as much as his logic has personal appeal I realize it would be undue Weight to mention it (although one could argue NPOV). The modern synthesis hardened with natural selection as the center piece. GetAgrippa (talk) 15:44, 21 January 2008 (UTC)

Yes, mutations are still selected for. As the article currently states:

"Due to the damaging effects that mutations can have on cells, organisms have evolved mechanisms such as DNA repair to remove mutations.[21] Therefore, the optimal mutation rate for a species is a trade-off between short-term costs, such as the risk of cancer, and the long-term benefits of advantageous mutations.[25]"

Similarly, mutationism and neutralism are already discussed:

"Although natural selection is responsible for adaptation, the relative importance of the two forces of natural selection and genetic drift in driving evolutionary change in general is an area of current research in evolutionary biology.[58] These investigations were prompted by the neutral theory of molecular evolution, which proposed that most evolutionary changes are the result of the fixation of neutral mutations that do not have any immediate effects on the fitness of an organism.[59] Hence, in this model, most genetic changes in a population are the result of constant mutation pressure and genetic drift.[60]" Tim Vickers (talk) 18:20, 21 January 2008 (UTC)

Dang not the observant scientist I use to be. I need to read the article again. Just shows you how carefully crafted much of the text is. Thanks Tim!GetAgrippa (talk) 18:29, 21 January 2008 (UTC)

Can I join the fun of "argumenting logic", and natural selection, genetic drift and mutation pressure, etc ? !!! (GeorgeFThomson (talk) 05:43, 22 January 2008 (UTC))

For example: I argument that what you define as "genetic changes", caused by, natural selection, genetic drift, etc.; is to logic as, a organic robot, with adaptive power, for it's

environment, but with limits, and general symetrical and logical results. All funny results in progeny, are of course, won out, by the better results ! But there seems to be a common tool of DNA, in all beings organic, making it quite a "too specific result" !!! Modeling to receive a result is a key to the mystery of life ! Self modeling yourself to become a human is fantastic: seems to a correct definition of Darwinian Evolution ! (GeorgeFThomson (talk) 05:52, 22 January 2008 (UTC))

Interesting point of view but this is not an article on logic but biological evolution. Do you have specific issues of concern in the article you want to address that will help improve the article? At one time we addressed Wolfram's cellular automata but I think it has been removed???Regards GetAgrippa (talk) 12:57, 22 January 2008 (UTC)

Thanks. Yes I will see what I can suggest to this article. Anyway biological evolution, should be logical, as the word bio-logical (logical-bio) would suggest. And is what I mentioned partially above. Regards. (GeorgeFThomson (talk) 05:44, 23 January 2008 (UTC))

I am concerned about what you would define, or should define as "new traits" or "traits, and the limits or not of these "traits". It cannot be "limitless traits" ! Understanding well what, is micro and macro mutation, definitions, as far as I think I know. How can this article be improoved, to be more specific, on "traits", and what Science accepts ! (GeorgeFThomson (talk) 05:50, 23 January 2008 (UTC))

Number two question. Is a degree of more complex traits, from a species today, needed to proove biological Evolution. Or increase in complexity "traits" is not necessary ! I speak both spanish and english, so some misspelling might occur. By the way I do not defende religion. But I am a fervent searcher of "truths" whoever has them !!! (GeorgeFThomson (talk) 06:01, 23 January 2008 (UTC))

1. There are no such things as "micro" or "macro" mutations; just mutations. I don't understand the rest of your question. 2. No, an increase in complexity of traits isn't necessary. thx1138 (talk) 06:49, 23 January 2008 (UTC)

The second question assumes that evolution is directional but it is not, and organismal traits can become less complex too. David D. (Talk) 06:53, 23 January 2008 (UTC)

Well George I can tell you what "Science" accepts and it wasn't my papers. I had two submissions denied-never got that Science article before I retired. Hee, hee, hee. George does bring up an interesting point-not all traits are mutable and this is confirmed by regions of sequence conserved 100% in chordates, sequence dedicated to certain embryological processes are conserved, etc. Mutations are random but not random where they occur as there are hot spots found in all genomes sequenced to date. GetAgrippa (talk) 15:57, 23 January 2008 (UTC)

Thanks. So does the definition of bio-logical Evolution, need a better explanation, of the scope of "hereditary traits" ? Or are the "traits" possible, to prove, we developed, from such boundaries of "traits", as apes ? I am not defending here "intelligent design". But we do have to be clearer, in what is the "true" possible extent or scope of "biological evolution today" ! Or we are just "generalizing definitions" that is a logical mistake ! Just like talking in ignorance , or "ignoring the problem " ! (GeorgeFThomson (talk) 17:11, 23 January 2008 (UTC))

Just wait. I know TimVickers will point out that this is addressed somewhere in the article. I think he has it indelibly imprinted into his memory banks. Just wait a few decades Tim that memory will fade. Time Waits for No One. Mick Jagger-"Its Only Rock and Roll". Hee, hee,hee. GetAgrippa (talk) 17:16, 23 January 2008 (UTC)

Well complexity is addressed: "A common misconception is that evolution is "progressive," but natural selection has no long-term goal and does not necessarily produce greater complexity.[80] Although complex species have evolved, this occurs as a side effect of the overall number of organisms increasing, and simple forms of life remain more common.[81]" but I would be interested in seeing what reliable sources there are that define hereditary traits more clearly. Tim Vickers (talk) 17:44, 23 January 2008 (UTC)

Weird. I was just reading this Science article that brings up some interesting issues: Gratten J, Wilson AJ, McRae AF, Beraldi D, Visscher PM, Pemberton JM, Slate J. A localized negative genetic correlation constrains microevolution of coat color in wild sheep.Science. 2008 Jan 18;319(5861):318-20. PMID: 18202287 [PubMed - in process]GetAgrippa (talk) 18:13, 23 January 2008 (UTC)

These articles are also interesting:Darwinian Evolution Can Follow Only Very Few Mutational Paths to Fitter Proteins Daniel M. Weinreich, Nigel F. Delaney, Mark A. DePristo, and Daniel L. HartlScience 7 April 2006 312: 111-114 [DOI: 10.1126/science.1123539] (in Reports) Conserved Genetic Basis of a Quantitative Plumage Trait Involved in Mate Choice Nicholas I. Mundy, Nichola S. Badcock, Tom Hart, Kim Scribner, Kirstin Janssen, and Nicola J. Nadeau Science 19 March 2004 303: 1870-1873 [DOI: 10.1126/science.1093834] (in Reports). J, Zhu J, Williams RW.Mapping the genetic architecture of complex traits in experimental populations. Bioinformatics. 2007 Jun 15;23(12):1527-36. Epub 2007 Apr 25. PMID: 17459962 [PubMed - indexed for Holland JB.Genetic architecture of complex traits in plants. Curr Opin Plant Biol. 2007 Apr;10(2):156-61. Epub 2007 Feb 8. Review. PMID: 17291822 [PubMed - indexed for MEDLINE]There is a significant body of literature on E. coli about mutations and mutation rates and cost-benefits in evolution that I am sure that Tim is familiar with.GetAgrippa (talk) 18:18, 23 January 2008 (UTC)

Ok. I suppose you are not going to explain more the "traits" of the intro ! I just am convinced that the definition of bio-illogical evolution, you are using, is too general and not specific enough, to really explain what is "limited adaptability" of a species, and what are herederity aquired "traits" ! (GeorgeFThomson (talk) 21:35, 23 January 2008 (UTC))

Phenotypes, what else? David D. (Talk) 21:48, 23 January 2008 (UTC)

It might help me understand your argument if you could point to some reliable sources that make the same point as you do. Tim Vickers (talk) 21:46, 23 January 2008 (UTC)

My reliable sources are pure sciences like Biology and molecular Biology ! And my new argumentation of pure (all degree of logic/illogic) logic, not published yet, but common sense logic ! (GeorgeFThomson (talk) 22:23, 23 January 2008 (UTC))

Roger. I take it you are saying, phenotypes (aquires, shape, conduct, etc), similar to "traits", and genotypes, is more to do with genetics, and DNA. Although undoubtedly, they are interconected. (GeorgeFThomson (talk) 22:29, 23 January 2008 (UTC))

I just insist the definition you have of bio-logical Evolution, used here in Wikipedia, is "too general" and "not specific enough" ! (GeorgeFThomson (talk) 22:29, 23 January 2008 (UTC))

Well thank you, George, that is most illuminating. Tim Vickers (talk) 22:31, 23 January 2008 (UTC)

Also I find it hard for Science to say enfatically: Humans evolved, sex evolved, etc... Instead of saying, we believe so far, as a Theory, this or that. (24.86.57.61 (talk) 22:40, 23 January 2008 (UTC)) (GeorgeFThomson (talk) 22:41, 23 January 2008 (UTC))

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Need to redefine scope and focus of article?

The article's title is simply "Evolution", not "Theory of Evolution". When used without qualification "evolution" has 2 meanings: a theory about how one species develops from another, etc.; and the history of such developments in life on Earth. The intro should state both meanings of the standalone word "evolution".

It should then state the scope of the article, i.e. whether it covers the theory or the history or both.

In a previous discussion "Intro too genetically oriented" (now archived - it was getting a bit out of hand), I suggested that the article was too oriented towards genetics:

It ignores the fact that Darwin was concerned with "The Origin of Species" and genetics wasn't known in his time. It's also an incorrectly narrow point of view: paleontologists study evolution but to them genetics is just a tool (molecular phylogeny), not the core subject - and paleontologists with no specific training in genetics have contributed to the theory of evolution, e.g . Punctuated equilibrium; the same goes for ethologists, whose development of theories about co-operative and altruistic behaviour has owed more ot games theory than to genetics.
It dives into genetics without outlining the basic logic of Darwin's theory, which requires at least 1 source of variation and at least 1 pruning mechanism.
It largely ignores sources of variation other than mutations within 1 species - endosymbiosis is the IMO the most important of these, as it was responsible for eucaryotic cells; and it is not just an example of gene flow (see discussion under ""Intro too genetically oriented").

On looking through the article a bit more I find:

The first mention of meiosis has a cross-link but no explanation. IIRC there's a style guideline that says articles should be as free-standing as possible, and the failure to explain meiosis is violates that.
The "Heredity" section fails to mention that suntan and sunburn are not inherited (i.e. omits the famous "Central Dogma"). Another style guide instructs editors to state the obvious because it may not be obvious to newcomers to the subject.
A lot of the genetics assumes sexual reproduction, despite the fact that asexual microorganisms account for the majority of the history of life on earth and most estimates say they outweigh multi-celled organisms at present.
A lot of the genetics appears to be there for its own sake rather than to help explain either the theory of evolution or the evolutionary history of life on Earth, e.g. most of the sections "Mutation" and "Recombination". —Preceding unsigned comment added by Philcha (talk • contribs) 15:08, 24 January 2008 (UTC)

I think you need to reread the article. It does specifically say suntan is not inherited. The article is on biological evolution and not specifically Darwinian evolution-it really just needs to be a historical reference as the article should emphasize the present status since the Synthesis. Actually now ethologist and neuroethologist are examining the cellular and genetic basis of specific human behaviors and the mutations responsible for varied behaviors in humans. I know the article mentions your concern about asexual rep. and microbes also. The article is not about the Central Dogma nor is evolution limited or restricted by the convention. The audience needs to understand Heritable, Mutation, and Recombinations, and this is pretty much basic stuff in every evolution text and encyclopedia. Regards GetAgrippa (talk) 16:10, 24 January 2008 (UTC).

evollution

evolution is too complicated ... —Preceding unsigned comment added by 169.203.213.91 (talk) 21:23, 12 December 2007 (UTC)

However, dropping the 'l' makes it simpler... Tomandlu (talk) 13:14, 13 December 2007 (UTC)

Introduction to evolution is written to be simpler. Tim Vickers (talk) 21:37, 12 December 2007 (UTC)

It is an extremely complex science; perhaps why so many are quick to reject it over Intelligent Design. It does not take a lot of brains to understand that "God Did It". The Introduction to Evolution article hopefully serves as a good transition between the more detailed version here and the much simplier version in Simple Wikipedia. Plus ... it made Good Article Status!--Random Replicator (talk) 13:12, 13 December 2007 (UTC)

Actually, it's rather simple. Now understanding the theory of evolution through natural selection is a different topic altogether.--Svetovid (talk) 19:02, 15 December 2007 (UTC)

The basic ideas are pretty simple. However, like any other subject, when you start investigating in more detail you rapidly run into a lot of complicated details. -- Writtenonsand (talk) 18:25, 2 January 2008 (UTC)

Pure Logic is back, and joint quest. Evolution is to Design, as What was first: the unicell, or DNA, that is a "too long information device", or Carbon, Hidrogen, Oxigen, etc. ! Wow ! Seems simple, and it is not ¡!¡!¡!

User: George F. Thomson. I forgot my sign in password. —Preceding unsigned comment added by 24.86.41.111 (talk) 19:09, 18 January 2008 (UTC)

...wow. Sheep81 (talk) 19:14, 18 January 2008 (UTC)

Pure Logic is back, and joint quest. Evolution is to Design, as What was first: the unicell, or DNA, that is a "too long information device", or Carbon, Hidrogen, Oxigen, etc. ! Wow ! Seems simple, and it is not ¡!¡!¡! Please do not erase, but "eat" this bit of nice scientific cheese ! ! ! It is me ! ! ! Kind regards to all ! (GeorgeFThomson (talk) 19:51, 18 January 2008 (UTC))

I'm not understand what you are trying to say. Are you stating that Evolution is Design?--Dumaka (talk) 20:36, 28 January 2008 (UTC)

debate section needed badly

The controversy of the Carbon 14 dating- examples like the Mammoth that had body parts that were dated using carbon 14 dating method which determined the Mammoth must of had a leg 50,000 years older than the rest of the animal.

The petrified trees controversy should be listed- petrified trees are found laying vertical through "eras".

Dr.Dino.com is a good place to find many of the arguments. Currently Dr. Hovin will pay $250,000 dollars if someone can prove evolution, and he will pay $200 to teachers or scientists to debate him. —Preceding unsigned comment added by Bajatmerc (talk • contribs)

There is no such mammoth: IIRC, it was a story fabricated by Kent Hovind (whose "prize" is bogus, as those who have tried to claim it have discovered). And there isn't a problem with polystrate fossils either (see TalkOrigins). And in case you hadn't heard, Hovind is in prison, and will be there for the next decade, so it isn't exactly easy for him to take part in debates nowadays. But this is NOT the place to debate evolution. --Robert Stevens (talk) 21:25, 3 January 2008 (UTC)

The claim that the leg was 50,000 years older than the rest does not seem quite right since C14 analyses are only effective going back 50,000 years and increasingly questionable to 70,000 years after which C14 dating is of no use. Petrified trees were found laying vertical through eras? So what? The tree fell and was slowly covered up. 72.153.100.125 (talk) 00:36, 26 January 2008 (UTC)

I did some searching and http://www.theconservativevoice.com/article/22457.html explains that he was suppose to be exempt from the taxes. It goes on to state more about his case however, I don't think this is the real issue here. Please give me a link to the part of TalkOrigins that you believe to be pertinent. —Preceding unsigned comment added by Bajatmerc (talk • contribs) 21:42, 3 January 2008 (UTC)

Some people believe that Carbon 14 dating does not work. Evidently you believe it works. However, both sides should be represented regardless of your personal bias.

My "personal bias" is towards those who are right and away from those who are wrong. But my "bias" is not relevant. Go to the top of this page and click on the "Evolution FAQ" link, which will explain Wikipedia policy on this issue.

BTW, Hovind had a long history of deliberate tax evasion (with outstanding warrants for his arrest in several states over a period of years). That's why he got hit so hard. --Robert Stevens (talk) 21:56, 3 January 2008 (UTC)

GSlicer (t • c) 22:07, 3 January 2008 (UTC)

We have articles here on various aspects of the creation-evolution controversy, like Objections to evolution and Misconceptions about evolution, however we do not cover all the parts of the controversy (I hate to call it a debate) as fully as TalkOrigins or TalkReason or other related sites. The nonsense about carbon 14 dating is just that; nonsense. The National Institute of Science and Technology has a laboratory that is involved in calibrating and comparing these dating methods. Check out their website; there are no problems. There are literally 100s if not 1000s of dating techniques, not all involving radioactive decay, such as dendochronology (counting tree rings), counting layers of mud at the bottom of oceans, lakes, sediment from rivers, snow layers in Antactica and Greenland, growth layers in coral (going back well over 100 million years), magnetization stripes in sediments and ocean basalts, and so on and so forth. And guess what? All these and other dating methods agree with each other. No discrepancies. No conspiracies. It is all BS invented by crooks to trick you out of your money which they use to support their "ministries". Hovind is a liar and a crook in several different ways. An evil evil man.

By the way, there is a prize offered by the Amazing Randi for 1 million dollars which any creationist who can prove their claims can win. Of course, in years and years, none have ever made their case. The existence of a prize proves very little. The Flat Earth Society had a prize they offered to anyone who could prove that the earth was not flat, and they never gave the prize out to anyone. They also never lost a debate, ever, even when debating the most illustrious scientists from Oxford, Cambridge and the Royal Society. So prizes and debates don't really prove much.--Filll (talk) 22:54, 3 January 2008 (UTC)

Introduction to Evolution

A section that was quite sophisticated for Introduction to Evolution seems appropriate to this article. Hope it is OK. Cheers! Wassupwestcoast (talk) 17:44, 24 January 2008 (UTC)

Thanks, I moved it to after the Heredity section and am condensing it a bit. Tim Vickers (talk) 18:15, 24 January 2008 (UTC)

Or is it better in variation? David D. (Talk) 18:27, 24 January 2008 (UTC)

Thanks Wassupwestcoast! I had suggested much the same. The Intro to Evo article has a number of really good contributions. GetAgrippa (talk) 18:47, 24 January 2008 (UTC)

A section on Barriers to Speciation from Introduction to Evolution was also too sophisticated for that article but might be more appropriate here. Cheers! Wassupwestcoast (talk) 20:09, 26 January 2008 (UTC)

Since it's a Featured Article, the AfD seems likely to fail. However, one point which came up in the stress of FA nomination clarified Darwin's continuing belief in inheritance of acquired characteristics, later known as Lamarckism or Neo-Lamarckism when it was opposed by Weissmann's findings and a strict application of natural selection, confusingly called Darwinism or Neo-Darwinism. The historical section here seemed rather muddled on this point, so I've revised it, adding a couple of refs and commenting out one which presumably was incorrect. .. dave souza, talk 21:15, 29 January 2008 (UTC)

PageNumbers

Mayr, Ernst (1970), Populations, Species, and Evolution, Cambridge, MA: Belknap Press of Harvard University Press, ISBN 0674690109

Does anyone have this book that could look up the specific pages where he references speciation in cichlids? --Random Replicator (talk) 18:11, 27 January 2008 (UTC)

Why not condense the more recent literature the last thirty years. Well maybe not-there is 89 references related to speciation in cichlids. Maybe there is a recent review article. Regards GetAgrippa (talk) 00:48, 28 January 2008 (UTC)

This book is in the library at my uni, but it's a public holiday here today so naturally I'm slacking off at home :) I'll be back at uni tomorrow and I can look it up for you then if you still need it. Ben (talk) 01:07, 28 January 2008 (UTC)

I am going to suggest that we put this article up for deletion, so this is not really necessary. I have been convinced that it is unneeded and unwanted. Thanks.--Filll (talk) 04:14, 28 January 2008 (UTC)

Ok, I went through the book and I found where he references the cichlids, but it seems only the first part of the paragraph in the Intro to evolution article is Mayr's (that I could see anyway). I added a new reference with the page number to the Intro article in the first part of the paragraph. As for the second part, Mayr does reference a paper by Greenwood: The Cichlid Fishes of Lake Nabugabo published in the Bulletin of the British Museum - Natural History (12:315-357). We may need to go hunting for it in that paper. Unfortunately, I don't have access to this one though, sorry. Ben (talk) 01:34, 30 January 2008 (UTC)

Introduction looks wrong

"In biology, evolution is a change in the inherited traits of a population from one generation to the next. This process causes organisms to change over time." Eh, organisms don't change over time, excluding acquired characters which aren't evolution, but a succession of organisms successively have different traits so that eventually they can become so different from their ancestors as to be a new species. The Introduction to evolution introduction is much more accurate on this point. .. dave souza, talk 21:24, 29 January 2008 (UTC)

organisms --> species? Sheep81 (talk) 21:33, 29 January 2008 (UTC)

Isnt it organisms--->populations of organisms?--Filll (talk) 15:05, 30 January 2008 (UTC)

New HGT section

Someone added a new section on horizontal gene transfer. It's redundant with information later in the article and complete unsourced. Thoughts? Sheep81 (talk) 21:36, 29 January 2008 (UTC)

You are correct it is redundant from Gene flow section. Perhaps we should just remove it and see if the editor wants to justify the edit. GetAgrippa (talk) 14:29, 30 January 2008 (UTC)

Soay sheep

Can the recent discussion on the evolution of the above be mentioned - a suitable reference is [1]. Jackiespeel (talk) 18:27, 29 January 2008 (UTC)

That is a nice article and a nice result confirming evolution. I would suggest that we include it in evidence of natural selection and include the peer-reviewed publication as a citation as well. Thank you for that. Beautiful result.--Filll (talk) 20:08, 29 January 2008 (UTC)

Looks good – is this an example of natural selection undoing artificial selection? ...... dave souza, talk 21:24, 29 January 2008 (UTC)

Here is the Science article about the soay sheep (a better reference):Gratten J, Wilson AJ, McRae AF, Beraldi D, Visscher PM, Pemberton JM, Slate J. A localized negative genetic correlation constrains microevolution of coat color in wild sheep.Science. 2008 Jan 18;319(5861):318-20. PMID: 18202287 [PubMed - in process].

Here is another earlier related article about another trait-horns:Robinson MR, Pilkington JG, Clutton-Brock TH, Pemberton JM, Kruuk LE.Live fast, die young: trade-offs between fitness components and sexually antagonistic selection on weaponry in Soay sheep.Evolution Int J Org Evolution. 2006 Oct;60(10):2168-81. PMID: 17133873 [PubMed - indexed for MEDLINE] Regards GetAgrippa (talk) 15:00, 30 January 2008 (UTC)

Another good idea Fill-"Evidence of Natural Selection" would make an excellent addendum to the evolution related articles. Just example after example of good models of evolution and natural selection. Stickleback fish, Darwin's finches, Soay Sheep, various insects, reptiles, mammals, and microbes. I note people often express that evolution is a theoretical science because they are naive of the vast number of examples and literature that demonstrates the evidence of natural selection. I am sure it would be criticized as not being an organized article but a list of examples, but I think it would be an excellent resource. I also agree with your sentiments concerning "introductory" articles. I have always tried to emphasize "basic and advanced" but it is the same idea. GetAgrippa (talk) 14:15, 31 January 2008 (UTC)

Directional Evolution - Malthusian Relativity

Lars Witting has proposed a mechanism whereby evolution can be directional with respect to increasing size and complexity over time. This theory is in contradiction to the mainstream view outlined in the Outcomes section:

A common misconception is that evolution is "progressive," but natural selection has no long-term goal and does not necessarily produce greater complexity.[86] Although complex species have evolved, this occurs as a side effect of the overall number of organisms increasing, and simple forms of life remain more common.[87]

I think it is important that this hypothesis should be at least mentioned in the article. A summary of the theory plus downloadable PDFs of his book (Witting, L. 1997. A General Theory of Evolution: By selection by density dependent competitive interactions) can be found on his website: http://www.peregrine.dk/wit.html. His publications don't seem to have attracted much scientific attention, but the theory is well argued and I think should be included here. --Graminophile (talk) 19:31, 31 January 2008 (UTC)

I think you just hit on the problem there: "His publications don't seem to have attracted much scientific attention." Wikipedia reports on what the scientific consensus is, we don't determine it. Until the scientific community starts to pay attention to this, it's not our place to do so. --Infophile ^{(Talk) (Contribs)} 19:34, 31 January 2008 (UTC)

I agree with Infophile, please read our policy on undue weight. Tim Vickers (talk) 19:36, 31 January 2008 (UTC)

If he has his work in some WP:RS we can examine it, but even then it would probably be more appropriate for evolution of complexity, which is linked from this article. You might also be interested in the historical theory of orthogenesis.-Filll (talk) 19:38, 31 January 2008 (UTC)

Re WP:RS - See the website for a list of scientific papers. E.g. this paper in "Journal of Theoretical Biology": Major life-history transitions by deterministic directional natural selection

Re Orthogenesis - read the summary of the theory here. Orthogenesis is concerned with mystical forces and as such is nonsense. Witting's theory is rooted firmly in population biology. I'm not proposing the Evolution article should be totally rewritten, merely that this merits a brief mention with reference in the appropriate paragraph. --Graminophile (talk) 19:59, 31 January 2008 (UTC)

That Journal of Theoretical Biology paper might be notable enough to be mentioned in evolution of complexity, but this appears to be the work of one man who has not gained much attention in the field. Not really important enough for the top-level article - compared to Darwin, Mendel, Dawkins or Gould. Tim Vickers (talk) 20:07, 31 January 2008 (UTC)

Read WP:UNDUE if you have a chance. It states that tiny-minority views (which this is) shouldn't be mentioned at all. --Infophile ^{(Talk) (Contribs)} 20:21, 31 January 2008 (UTC)

There are a number of published theories and ideas concerning evolution-like neophenogenesis. I agree the undue weight clause is applicable. The undue weight argument is good, but apparently not good enough to rid us of an article like the Duesberg's hypothesis article concerning AIDS. GetAgrippa (talk) 20:37, 31 January 2008 (UTC)

I take the point about undue weight. However, I find it somewhat ironic that Tim mentions Dawkins in the light of this paper by Dawkins & Krebs. See the section on "Intraspecific symmetric arms races" starting on p. 68. For instance:

Imagine a species in which large size is an advantage in male-male competition but not an advantage from any other point of view. It is entirely reasonable that competition will favour males that are slightly larger than the current population mode, whatever the current mode may be (Simpson 1953). This is a recipe for progressive evolution of the kind that we expect from an arms race.

Essentially, the concept is identical to that proposed by Witting. Cope's rule is also relevant, in that a progressive size increase has been observed in many lineages but without a mechanism to explain it. So, although Witting's work itself is fairly obscure, the idea of inherent directionality in evolution is not (i.e. as a bona fide scientific theory). So, I think at least a short reference to this idea (even if not Witting himself) should be in the main article. --Graminophile (talk) 22:58, 31 January 2008 (UTC)

I missed out Cope's rule since this is the center of much dispute, eg PMID 16701331 and there is still a lot of skepticism as to if this is a genuine effect, or just a result of sampling error. Again, these more specialised and less well-known ideas could go well in the specialised article on evolution of complexity, but are not well-enough established to go in the main article. Tim Vickers (talk) 23:19, 31 January 2008 (UTC)

Remember a number of laws and rules have fallen out of vogue. Dollo's law, Williston's law, but I believe Cope's rule still has some merit. Gould spoke of it in Structure of Evolutionary Theory although he suggest its just a trend. GetAgrippa (talk) 02:05, 1 February 2008 (UTC)

Biased

This discussion has been closed. Please do not modify it.

The following discussion has been closed. Please do not modify it.

this article is biased if i ever read it. iT doesn't present the problems within the evolutionary theory, and it certainly doesn't display creationism as a credible science. It needs some creationistic perspective. —Preceding unsigned comment added by 208.102.188.29 (talk) 01:12, 1 February 2008 (UTC)

The Evolution FAQ adresses this. Ben (talk) 05:19, 1 February 2008 (UTC)

It doesn't represent creationism as a credible science? Thank goodness for that! Creationism is not credible science. It needs a creationist perspective? I don't think so.Cliff (talk) 09:24, 1 February 2008 (UTC)

Additionally, which creationism? Creationism isn't a monolith of thought; how many noticeably different formulations are found in Christianity alone, let alone every other religion that has an origin story? Are we supposed to buy that one of these creationisms works when all of them appear quite clearly to not fall under the purview of science? J. Spencer (talk) 14:58, 1 February 2008 (UTC)

This article is not about that. Look at creation-evolution controversy or creationism or creation science to get started. However, well in excess of 99.9% of all scientists in relevant fields do not accept creationism as science, and therefore by the rules of Wikipedia we are not allowed to either. Thanks.--Filll (talk) 15:22, 1 February 2008 (UTC)

An interesting creative commons image

A helix of popular science books on evolution, genetics and related topics... http://www.flickr.com/photos/seriykotik/228087914/ It's got a creative commons licence, but we'd have to be *really* creative to find a use for it on wikipedia. Any ideas? Edhubbard (talk) 20:35, 2 February 2008 (UTC)

Evolution/Creationism images up for deletion

The following images are up for deletion: Image:Leonard Darwin.jpg, Image:Causes of evolution.jpg, Image:Design inference.jpg, Image:Blind Watchmaker.jpg. As the original uploader is inactive, I thought somebody who knows the image-copyright process might like to take a look to see if they're worth saving. Hrafn^Talk_Stalk 02:19, 14 February 2008 (UTC)

whitespacing

Is there consensus on WP about whether extra whitespace should be used to space out articles for image flow? I tend to think the extra whitespace looks horrible, but that's me. Implict in this question: should we remove the extra whitespace used in this article? Kellen^T 14:01, 16 February 2008 (UTC)

Software for the simulation of evolution

Hello! I just finished a little software tool that allows you to simulate (veeeery much simplified of course) evolution. I think it is a good example to see how evolution works. Could anyone please add it to the external links list? http://www.villalachouette.de/william/krims/simplEvolution.zip

All the best, --84.142.215.88 (talk) 14:52, 18 February 2008 (UTC)

As interesting as this is, I am not sure this article is the place for this. I am not sure which article if any would be relevant for this. We probably should have an article about numerical simulation of evolution, but I suspect we do not. Comments?--Filll (talk) 15:03, 18 February 2008 (UTC)

Hi! I think this article would be the right place. The software provides simply a basic practical application for aaaaaalllll the theory about evolution. I think some people that use wikipedia don't enjoy theory that much (e.g. school kids). They want to understand something as cheap and as fast as possible (like me btw). These people like simple practical examples. I like simple practical examples too (although i also like theory). Wikipedia has the advantage to include things like software tools in the article. Printed literature does not have this opportunity, so this is one of the main advantages that wikipedia should always be aware of. William --84.142.215.88 (talk) 16:27, 18 February 2008 (UTC)

Actually at one point there were three evolution computer simulators. I personally thought all of them were uninteresting and poor examples. Why not give real examples rather than some computer generated example? I think that would have much more impact and application. Give a real example of speciation, the environmental cause for natural selection, and the genetic shift in gene alleles associated with the trait or phenotype. Watching a computer simulation is like playing Pacman to me. Also I don't think the layperson would have gotten much from the previous simulators but this maybe improved. GetAgrippa (talk) 17:00, 18 February 2008 (UTC)

I think it would be great to have an article like Numerical simulation of evolution and to then link to these simulators there.--Filll (talk) 17:13, 18 February 2008 (UTC)

Why not expand it to numerical simulators and models so we could include Wolfram's cellular automata, and other proposed mathematical models of evolution. I still like Fill's idea of an article of examples of Natural selection. GetAgrippa (talk) 00:06, 19 February 2008 (UTC)

Cellular automata don't really model evolution by natural selection. Artificial life systems such as Tierra are probably more what's being looked for. --FOo (talk) 00:51, 19 February 2008 (UTC)

Absolutely!Wolfram rants natural selection is not needed. I'm not particularly fond of his work-I was joking about him-long story! But evolution modeling is a worthy subject and a topic I have mentioned before, and I like Fill's idea about a Nat Sel article. The computer simulators seems a topic worthy of an article. GetAgrippa (talk) 03:32, 19 February 2008 (UTC)

Questionable sources

Hi everybody, a proposal is being made to ease the current restrictions on the use of questionable sources (which might include self-published creationist websites) in the verifiability policy. I think editors here might have a useful viewpoint on this proposal. See Wikipedia_talk:Verifiability#Restricting questionable sources to articles about themselves. Tim Vickers (talk) 20:53, 19 February 2008 (UTC)

"Theory"?

Well, I guess Wikipedia doesn't hold evolution to be a theory. Nothing like good old-fashioned bias! Oh wait...there's a "fact vs. theory" page that tries to justify it...I guess that page makes it ok to ignore that it's a theory, since a bunch of untrained, random, self-qualified individuals said so. Good thing people are waking up to Wikipedia's agenda-ridden stranglehold on internet "truth." —Preceding unsigned comment added by 64.252.187.93 (talk) 05:14, 21 February 2008 (UTC)

Thank you for your considered comments. I am sure you will find everything you need here. Snalwibma (talk) 08:24, 21 February 2008 (UTC)

The random untrained individuals you are worrying about include dozens of PhDs and Professors. And evolution is both a fact and a theory, as noted by dozens if not hundreds of reliable sources including the National Academy of Sciences. If you have a problem, contact the NAS with your complaint and try to get them to change their definition, not us. We just report their statements.--Filll (talk) 16:46, 21 February 2008 (UTC)

"Good thing people are waking up to Wikipedia's agenda-ridden stranglehold on internet "truth."" I find that statement hilarious. This article is the results of consensus between evolutionary biologists, scientists, and laypersons-all contributions are welcome with appropriate justification and references. Nobody is just making it up and personal opinions are not welcome-no matter the opinion. It is a science article plain and simple, and the editors in good faith have tried to create an excellent encyclopedic article. The idea is to educate people not saturate them with personal opinions-nothing against your opinion. GetAgrippa (talk) 17:50, 21 February 2008 (UTC)

Talk thread apparently deleted: "Need to redefine scope and focus of article?"

On 24 January 2008 I last contributed to a thread "Need to redefine scope and focus of article?", in which I questioned the article's extreme depedence on genetics (after all Darwin knew no genetics). That thread is no longer visible on this page or in the most recent archive. Whoever did the archiving needs to sort this out. Philcha (talk) 09:14, 21 February 2008 (UTC)

Why? This article is about biological evolution-not Darwinian evolution. Even Darwin's view of natural selection has a vague resemblance to todays definition. It would be an injustice not to emphasize a genetics based view since the definition of evolution is genetic and pop geneticist modeling is central to modern evolutionary biology. I guess we can present a strawman argument that inheritance is passed by gemmules as Darwin believed and give the creationist a bone to chew on. I am not surprised by the archiving but it must have been an accident to erase your post. GetAgrippa (talk) 14:55, 21 February 2008 (UTC)

What you are looking for is in articles here on history, like History of evolutionary thought. This article is about current science, not the history.--Filll (talk) 16:47, 21 February 2008 (UTC)

I fixed the archive issue, the current archive wasn't linked in the box. Tim Vickers (talk) 17:35, 21 February 2008 (UTC)

Thanks! Philcha (talk) 13:33, 28 February 2008 (UTC)

Sockpuppet vandalism

With the recent increase in disruption, administrators seeing one of these sockpuppets vandalising the page should fully-protect the article and then report the account to a checkuser for an IP block and a sweep to find and block the other accounts that the vandal will have created. Tim Vickers (talk) 17:44, 29 February 2008 (UTC)

Removal of horizontal gene transfer section

Hi there, I've removed this section since it duplicated the material in the final paragraph of the gene flow section. Since the page is currently protected editing is limited, but if anybody objects to this just say so here and I'll revert myself. Tim Vickers (talk) 20:13, 29 February 2008 (UTC)

Article now back to semi-protected. Tim Vickers (talk) 22:41, 29 February 2008 (UTC)

I'm not happy about the removal of "Horizontal gene transfer", although I can't be as specific as I'd like about why without further study. The "Gene flow" section currently is approx. 80% about sexually-reproducing organisms, mainly animals. Horizontal transfer among single-celled organisms is a completely different matter, IIRC: it's routine, and by no means limited to within "species", e.g. antibiotic resistance (whatever "species" means for asexual organisms); there are more mechanisms (viruses; plasmids; "equal" exchange of genes between 2 individuals, not always of the same "species"; gene donation, usually fatal to the donor, but the recipient quickly re-shuffles the genes and divides) - and that's what I dimly recall off the top (possibly from something by Lynn Margulis), and without getting into endosymbiosis and its consequences; and without getting into Williamson's Larvae and Evolution (horizontal gene transfer between very different sexually-reproducing metazoa). I fear that this may turn out to be another case of the article's taking too narrow a perspective; unfortunately I don't have time to research the issues right now because someone's asked me to have a go at something else and it requires a big change of perspective from what prompted them to ask (i.e. a lot of research). PS: have you noticed this post is already longer than the one surviving para about horizontal gene transfer? Philcha (talk) 23:48, 29 February 2008 (UTC)

Controversy

Don't know how this works too well. However, there is a glaring mistake in the first part of this article. It says that the scientific community universally accepts the theory of evolution. That is not true. There are many Christian scientists that do not believe in the evolutionary theory of man. Universal means everybody or practically everybody and that is clearly not the truth when it comes to the universal acceptance of the theory of evolution by the scientific community. This should be changed, at least, to include the word almost. However, that would not even be a fair evaluation of the current differences of opinion in the scientific community regarding this subject. Please edit accordingly. Thank you Oceanberg6 (talk) 00:53, 23 January 2008 (UTC)

See Section 1 and Section 2 of the FAQ Tim Vickers (talk) 02:59, 23 January 2008 (UTC)

Well over 99% of earth and life scientists support evolution. That is universal even by your definition stated above. Sheep81 (talk) 05:58, 23 January 2008 (UTC)

No, no. Universal would be "all" unless used in a metaphorical sense (are there exceptions to the universal laws of physics). Just like the universal joint in my car. Hee, hee. Just couldn't help myself. GetAgrippa (talk) 17:06, 23 January 2008 (UTC)

While you are right in a very strict sense, 99% agreement should be called "universal". If not, we had to say things like "Most scientists think, that the earth is not flat", instead of "The scientific community universally accepts the theory of the earth beeing round". 84.177.219.106 (talk) 21:57, 12 February 2008 (UTC)

Of those who signed the petition A Scientific Dissent from Darwinism, about 100 of them are biologists in the US (not all active, some retired etc). There are more than 1.2 million biologists in the US. So if you use this as a measure, those who did not sign the petition represent more than 99.992 percent of the biologists in the US. Is this universal? I do not know, but it is a huge majority. See Level of support for evolution.--Filll (talk) 18:00, 23 January 2008 (UTC)

Not to mention Project Steve. Sheep81 (talk) 19:54, 23 January 2008 (UTC)

Fill I am sure you have examined the issue per continent to get a global feel. The majority on every continent also accept evolution?? Even the majority of faithful believe in theistic evolution. Seems every way you look at it, it is universally accepted. Wikipedia states undue Weight can abrogate the mention of a minority view. GetAgrippa (talk) 20:09, 23 January 2008 (UTC)

The issue is not whether a majority of the population accept the evidence, the issue is if the scientific community is convinced - it is. Tim Vickers (talk) 20:13, 23 January 2008 (UTC)

We can probably agree that "universal among scientists" isn't the best way to put it, since that would be falsified by a single sociologist who doesn't accept evolution. How can we phrase it to convey that there's no serious debate among the experts, without speaking in absolutes? Gnixon (talk) 20:54, 23 January 2008 (UTC)

Having a lot of friends who majored in ~~drinking~~sociology in college, I question whether that counts as "science". Heh. :)

Using a word like "essentially" or something like that in front of "universal" communicates the fact that there a couple holdouts while still getting across that the overwhelmingly massive majority of scientists of all stripes accept evolution. Sheep81 (talk) 21:23, 23 January 2008 (UTC)

Taking what Tim said a step further, the point isn't even whether essentially all scientists accept evolution---who cares what a chemist thinks?---the point is that the community of experts-on-the-matter is convinced. If we can fix that unwieldy, anthropomorphising statement, then we're done. Gnixon (talk) 22:45, 23 January 2008 (UTC)

Exactly. Who cares what a chemist (or physicist for that matter) thinks. CabalCounterIntelligenceUnit (talk) 01:09, 24 January 2008 (UTC)

Physicists, chemists, astronomers and geologists are still scientists capable of rationally analyzing scientific data and evaluating the conclusions of others. All of these disciplines (especially chemistry, good God!) also have bearing on the life sciences so their input is invaluable. I doubt you will find much support outside of this talk page for the position that non-biologists' opinions aren't relevant in this matter! Sheep81 (talk) 01:17, 24 January 2008 (UTC)

I agree that other scientists are probably better equipped than non-scientists to judge the validity of a theory, but an encyclopedia hardly needs to appeal to them unless the credibility of biologists is suspect. I would go further than you did and say that many people outside of science are "capable of rationally analyzing scientific data and evaluating the conclusions of others." Of course some chemists, physicists, astronomers, and geologists are experts on matters relevant to evolution, and I imagine certain kinds of biologists could have a good career without knowing squat about evolution. I figured you'd give me enough credit that I could leave out all the qualifications while making my point. :) Gnixon (talk) 05:34, 24 January 2008 (UTC)

Um there are more physicists and chemists who support creationism than biologists and geologists, who are in the sciences that deal with evolution regularly. However, you are welcome to edit Conservapedia.--Filll (talk) 01:36, 24 January 2008 (UTC)

Who are you talking to here?? Sheep81 (talk) 01:38, 24 January 2008 (UTC)

So, anyway, is there a better way to say it? Gnixon (talk) 05:38, 24 January 2008 (UTC)

IMO you have yet to establish why it needs to be changed. What's the motivation for the change? Is it inaccurate? Is it misleading? The sentence is not "appealing" to anyone, it's a simple statement of fact. What is wrong with saying that there is near-universal acceptance within the scientific community? Why limit the sentence to just life scientists when the more inclusive statement is also true? Put another way, who cares who cares what a chemist thinks? Sheep81 (talk) 06:28, 24 January 2008 (UTC)

Okay, sorry if it seemed like I was trying to cut off discussion about the sentence. "Essentially universal" is certainly true within today's scientific community. But to me, the important thing is that biologists stopped debating whether evolution happened soon after Darwin.

If we want to go beyond that, we need to ask what it adds. Was there "essentially universal" acceptance of evolution among physicists "soon" after Darwin? I doubt we could find a source to answer that question, and to me, it's beside the point---they weren't the experts. Even today there are surely more creationists among chemists and physicists than among biologists, so if you want to add chemists and physicists, you have to make a less strong statement about universality.

There's just not a good way (or a need) to include broader classes without weakening the statement or adding extra clauses. To give an extreme example, we could truthfully say that "the majority of people in the developed world accept evolution," but the truth of the matter doesn't depend on a vote. It's stronger and more to the point to simply say that biologists stopped arguing about it after Darwin. (edit conflict with Philcha) Gnixon (talk) 13:43, 24 January 2008 (UTC)

Calm down, everybody. The intro says "essentially universal acceptance". IMO "essentially" is very close to weasel words because it tries to claim that acceptance is as good as universal without quantifying - especially since "soon led to ..." is also unspecific. If we could find a recent poll somewhere, that would be ideal. Failing that, I suggest "overwhelming acceptance" - that gives the right impression and would still be accurate if as many as 10% of qualified and practising scientists rejected evolution (although the actual % of rejectionists is probably much lower). Philcha (talk) 13:37, 24 January 2008 (UTC)

I just don't think we need to open the door to the question of precisely how well evolution is accepted among population X, especially not in the lead. What matters is that the community of experts (biologists) stopped arguing about it in the 1860s. Gnixon (talk) 13:47, 24 January 2008 (UTC)

Guys, this is about the language of the article. If anyone wants to open a page to debate evolution I would gladly join you, but this is about the article. I just want to say that logically, yes logically, universal means ALL. If there is even one dissenter in the scientific community, then the use of the word "universal" would be logically false. 2-17-08 —Preceding unsigned comment added by 98.195.196.19 (talk) 15:18, 17 February 2008 (UTC)

References

I think that when one makes a controversial statement like "essentially universal acceptance" it should be linked and/or referenced. The thing is, because of assorted propaganda by creationists and public relations campaigns, the average person thinks that maybe 30 % or more of scientists disagree with evolution. The average person thinks about the petition A Scientific Dissent from Darwinism or the movie Expelled: No Intelligence Allowed and thinks that the claim of "essentially universal acceptance" must be wrong, or a lie. If you make a sort of outrageous statement like that, you better be able to back it up. We do this in all the other articles of this sort.--Filll (talk) 15:28, 24 January 2008 (UTC)

Worth noting not ALL (100%) scientists believe the earth is round. Not all (100%) are convinced the stars you see are not christmas lights put there by the CIA. Not ALL (100%) scientists believe crystal worshipping is dumb. There are wingnuts in every profession, including science. This does not make the "round earth" theory or stars we see at night controversial nor does it prove crystals have any innate powers. Suggesting there is controversy within the scientific community over evolution is a creationist tactict used to instill doubt amongst those who do not know better. THAT is the controversy, the lying, cheating creationists and intelligent design proponents who misrepresent science and evolution. So this "controvery" is simply manufactured propaganda used for the purpose of creating doubt where there is none so they can eventually slip their religious ideas in the back door. Nice try, no cigar. Angry Christian (talk) 00:40, 25 January 2008 (UTC)

Well we have a whole article (Level of support for evolution) dealing with this. That article states there is over 99% acceptance among scientists. So if the issue is a citation, there should be some in that article we can copy and paste over here. Sheep81 (talk) 06:07, 25 January 2008 (UTC)

I agree with Filll's comment that claims about the scientific acceptance of the theory of evolution should be linked and/or referenced. I spent some time googling for polls / surveys of scientists, and found nothing - allegedly Gallup held a poll in 1996 but I could not find details of the questions or results. The best I've found:

"Today evolution is the unifying force in modern biology; it ties together fields as disparate as genetics, microbiology and palaeontology. It is an elegant and convincing explanation for the staggering diversity of Earth's five million or more living species" Special report on evolution (Jan 2008)
Statement on the Teaching of Evolution, AAAS (2006)
Statements from Scientific and Scholarly Organizations, National Center for Science Education
IAP statement on the teaching of evolution, Interacademy Panel (June 2006)

I'll add items 2-4 as refs. Philcha (talk) 12:31, 25 January 2008 (UTC)

Wait a minute, guys. Do we really want to use this lead to drive home the point about evolution being accepted by scientists? I now see three separate references to "evolution accepted soon after Darwin". Wouldn't just one do the job? Do any of them support "soon"? This seems to be opening a big can of worms, and I predict it will lead to a lot of conversation on this page that largely distracts us from describing evolution. Let's just say something simple and uncontroversial and move on. P.S., new scientist ref is great for last sentence of lead. Gnixon (talk) 16:56, 25 January 2008 (UTC)

1st ref is an AAAS statement from 1922, the earliest I could find. If anyone can find an earlier one, please use that.

Re number of refs, my experience of other articles is that more than 1 is needed to support phrases like "overwhelmingly accepted". Philcha (talk) 18:16, 25 January 2008 (UTC)

How about folding them into one footnote? How many references does Solar System need in order to say that the Earth revolves around the Sun? (Probably none, because the issue has been settled for eons.) Wouldn't it seem silly if Solar System said "There is essentially universal acceptance among scientists of the Copernican model of the Solar System." Gnixon (talk) 18:42, 25 January 2008 (UTC)

Your first reference is brilliant, Phil. Thanks for finding it! Sheep81 (talk) 03:19, 26 January 2008 (UTC)

I should have responded earlier to Gnixon's suggestion that the refs for "overwhelming support" should be folded them into one footnote - my apologies. I kept them separate because 2 of them are used elsewhere, so folding them would result in multiple citations of the same documents within the footnotes. Is there any way in which multiple footnotes can refer to the same citation? Philcha (talk) 09:01, 21 February 2008 (UTC)

Hi. Would it be helpful for the general understanding of all to include what appears to me to be a good latin mottoexplaining somehow more what Evolution of Life means to Evolutionists ? : VITA ORIUNDUS SUBSTANCIA FORTUITO : Life originates by chance from substance or mater. (Latin expression by : George F. Thomson, c.2008). Kind Regards. GeorgeFThomson (talk) 16:29, 11 March 2008 (UTC)

..................................................................................................

Chromosome number changes

I'm not in a habit of breaking Wikipedia policy, but I have a question to which I have not been able to find an answer. This seems like a good place to ask. I believe I have a good understanding of how evolution works, but I have not yet seen how evolution explains the difference in the number of chromosomes between organisms. Humans have 46; but some species have over a hundred, and it is (as best I have found) always an even number. Could someone direct me to an overview of how this process works? It might make a worthy addition to this article (or the chromosome article) if it has not been explained there yet. Thanks. ~ S0CO^{(talk|contribs)} 23:00, 3 March 2008 (UTC)

Why it is that some species have up to 100 chromosomes, I don't know. Why it is that all species (or at least, all sexual species) have an even number of chromosomes is easy; they inherit one of each chromosome from their parents, so humans actually have 23 pairs. 22 pairs of autosomes and a pair of sex chromosomes: the X and Y chromosomes. For a nice accessible clear discussion of why humans have 23 pairs of chromosomes instead of 24 (as our primate ancestors do) see the PBS special on the Dover trial here. See in particular "Chapter 6". Edhubbard (talk) 23:23, 3 March 2008 (UTC)

(ps: as a general rule, science is good at answering "how" questions, but "why" questions are a little harder, or even really part of philosophy.) Edhubbard (talk) 23:25, 3 March 2008 (UTC)

Do a google search on "onion test" for more information about amount of DNA and organization etc in different organisms.--Filll (talk) 23:48, 3 March 2008 (UTC)

I posted your question on the science ref desk (Wikipedia:Reference_desk/Science#Chromosome_number_changes). Possibly you'll get some good answers there. David D. (Talk) 00:22, 4 March 2008 (UTC)

To the original poster: You may have been labouring under the same misconception that I was (and which confused the hell out of me). A different number of chromosomes does not prevent breeding. Therefore a change of chromosome numbers in a single individual does not isolate that individual. You might take a look at: Chromosome 2 (human) - bottom line, the number of chromosomes is probably the least significant part of DNA (you might compare it to having a one-volume copy of Lord of the Rings, to having 3 volumes - the content doesn't change). Tomandlu (talk) 12:57, 11 March 2008 (UTC)

RfC on Talk:David Snoke

There is a RfC on this talkpage at Talk:David Snoke#RfC: Does Desai & Fisher (2007) and Desai et al (2007) support Behe & Snoke (2004)? As the papers involve issues of evolutionary mechanisms, I thought that some editors here might wish to venture an opinion. Hrafn^Talk_Stalk 16:02, 11 March 2008 (UTC)

Latin motto

Hi. Would it be helpful for the general understanding of all to include what appears to me to be a good latin motto explaining somehow more what Evolution of Life means to Evolutionists ? :

VITA PRIMORDIUM ORIUNDUS SUBSTANCIA MINIMUS FORTUITO : Life originates arising by small chance from substance or mater. (Latin expression by : George F. Thomson, c.2008). Kind Regards. GeorgeFThomson (talk) 16:31, 11 March 2008 (UTC)

This does not strike me as particularly accurate for the modern scientific theory of evolution, or particularly useful for this article. Comments?-_Filll (talk) 16:10, 12 March 2008 (UTC)

Second sentence

The intro currently starts with these two sentences.

In biology, evolution is the changes seen in the inherited traits of a population from one generation to the next. These changes cause populations of organisms to alter over time.

I suggest the second sentence be changed, because the concept of a population altering is too vague. I mean, any time any member of the population dies or a new one is born, the population alters. That's not evolution, and would definitely not be if the newborn were a genetic clone of the newly deceased. What is evolution is the change in distribution of the traits in the population. That's why I suggest the second sentence be changed to:

These changes cause the distribution of traits within a given population of organisms to alter over time.

Comments? Suggestions? Questions? --Unflappable (talk) 22:49, 11 March 2008 (UTC)

Hi there, welcome to the evolution article. Your suggestion is quite correct, but perhaps a bit too technical for the beginner (think in terms of "high-school science" level). I obviously want to say "phenotypes", but that is also too technical for the introduction. What about "Evolution therefore causes the characteristics of these populations to alter over time." Tim Vickers (talk) 23:05, 11 March 2008 (UTC)

Comment from the peanut gallery: There is the Introduction to evolution article for the faint of heart. I think "distribution of traits" is at about the right level for the crowd this article should aim for: high school and up. Just my own thoughts on the matter. Silly rabbit (talk) 23:19, 11 March 2008 (UTC)

How about "These changes cause the distribution of genetic characteristics within a given population of organisms to alter over time." But I'd also be happy with "distribution of traits" as I think the second sentence is a bit vague. Sting au Buzz Me... 23:28, 11 March 2008 (UTC)

Since we have Introduction to evolution and even the Simple Wikipedia article on evolution, there is little reason to be imprecise here if need be. I say, even if it is a bit complicated, write it the way you think is appropriate.--Filll (talk) 23:32, 11 March 2008 (UTC)

Actually scratch my suggestion. On rereading the first sentence it is covered there (inherited traits of a population). So best to leave the second sentence as it is. Sting au Buzz Me... 23:41, 11 March 2008 (UTC)

Hi. By "leave the second sentence as it is", do you mean as it currently is in the article, or as I have proposed to change it above? Thanks! --Unflappable (talk) 23:51, 11 March 2008 (UTC)

I mean leave it as currently in the article. Otherwise we would just be repeating what is said in first sentence but using different words. Sting au Buzz Me... 00:01, 12 March 2008 (UTC)

Hmm. Yes, the specification of traits meaning heritable traits is in the first sentence, but not that what changes over time is the distribution of these traits in the population. Do you not agree that "cause populations to alter" is so vague as to be meaningless? How about combining the current first two sentences into one, and adding, well, the following?

In biology, evolution is alteration in the distribution of inherited traits of a population over time. These changes are relatively minor from one generation to the next, but accumulate with each subsequent generation and can eventually cause substantial and even radical changes given a sufficient number of generations.

I think it's important to capture right away the fundamental concept of relatively small changes between immediate generations potentially (and arguably inevitably) leading to enormous changes given enough subsequent generations. After all, isn't that what evolution is? Perhaps it's best to evaluate in the context of the entire intro paragraph:

In biology, evolution is alteration in the distribution of inherited traits of a population over time. These changes are relatively minor from one generation to the next, but accumulate with each subsequent generation and can eventually cause substantial and even radical changes given a sufficient number of generations. Inherited traits come from the genes that are passed on to offspring during reproduction. Mutations in genes can produce new or altered traits, resulting in the appearance of heritable differences between organisms. Such new traits also come from the transfer of genes between populations, as in migration, or between species, in horizontal gene transfer. Evolution occurs when these heritable differences become more common or rare in a population, either non-randomly through natural selection or randomly through genetic drift.

Better? --Unflappable (talk) 00:46, 12 March 2008 (UTC)

Looks pretty good to me, although "distribution" has a more common geographic meaning in normal speech, than the statistical sense you're using here. I think "changes in" is simpler and covers all the possibilities. Tim Vickers (talk) 04:54, 12 March 2008 (UTC)

But are changes in the traits themselves required for evolution? Or is alteration in the distribution of those traits enough? For example, if an isolated population moves from hotter/sunnier climates to colder/darker climates and the genes for lighter pigment become more and more predominant with each generation, is that change in the traits themselves, or just change in the distribution of the traits? Isn't it the latter, and that's evolution? I think the article should be clear on this point. --Unflappable (talk) 16:21, 12 March 2008 (UTC)

I would consider both a change in the frequency of existing traits in a population (such as from genetic drift), or the appearance of a new trait in a population (such as from horizontal gene transfer), as forms of evolution, so I think it is too narrow to simply define evolution as a change in trait distribution. As I understand it, any change in the traits of a population over time is evolution. Tim Vickers (talk) 16:44, 12 March 2008 (UTC)

First of all, it's not so much that "traits" change as it is that genes mutate. If the mutation of a gene leads to the expression of a "trait" that gives an individual with that mutated gene an advantage (in terms of producing viable off-spring, compared to those individuals without the mutation), then the percentage of the population (of individuals) carrying that mutated gene will increase from one generation to the next (as long as it remains advantageous!).

So, to answer your question(s): first there is a change in a gene, which causes a change in a trait, which if relatively advantageous in terms of producing viable off-spring leads to a change in distribution of that gene/trait. When you say "...become[s] more and more predominant..." you are yourself answering your own question: that could only mean "a change in the distribution..." -- unless you are wondering if perhaps somehow the same trait is occurring de novo -- ie. from a unique mutation each time -- for each individual in the population that expresses it! If so, then: no, that's not usually how it works...

Again: first a change in a gene → leads to a change in a trait → leads gradually to a change in the distribution of the changed gene and the changed trait (since the former leads to the latter) within a population.

—Wikiscient— 16:51, 12 March 2008 (UTC)

It doesn't have to be a mutation starting this off (though it often is). It could instead be a change in nature which causes a preexisting trait to become more favorable, and then those organisms who exhibit it are selected for. Of course, mutations do play a role in the larger sense, but they aren't critical for every instance of evolution. --Infophile ^{(Talk) (Contribs)} 16:59, 12 March 2008 (UTC)

Yes, right, true. In a (simplified) sense, though, all differences in genotype are the result of "mutation" (if you want to include under that term, for simplicity's sake, "recombination," too), which are then differentially "selected" according to ever-changing environmental circumstances... —Wikiscient— 17:10, 12 March 2008 (UTC)

Wikiscient, okay, a change in genes leads to a change in traits. I think this takes us to the question I pose in the next section. Put another way, is the only way trait changes (from which natural selection selects) result is from changes in genes (mutations)? I mean, can't a child develop a new trait given some new combination of genes acquired from his parents? Perhaps a new trait that even his siblings may or may not have? And can't that new trait be advantageous and heritable? Since traits often depend on combinations of genes, do the genes themselves have to change (mutate) in order for traits to change, or can they just combine differently to produce new, advantageous (in terms of natural selection) and heritable traits, without actual mutation of any genes? Actually, I now see Infophile has already answered this. Okay, then, I think the article could be more clear on this point. I, for one, would appreciate it. --Unflappable (talk) 17:04, 12 March 2008 (UTC)

Yes! (See below). —Wikiscient— 17:12, 12 March 2008 (UTC)

Third paragraph - natural selection contrasted with genetic drift.. why?

The third paragraph currently is:

Natural selection is a process by which heritable traits that are helpful for survival and reproduction become more common in a population, while harmful traits become more rare. This occurs because individuals with advantageous traits reproduce more successfully, so that more in the next generation inherit these traits.^[1]^[2] Over many generations, adaptations occur through a combination of successive, small, random changes in traits, and natural selection of those variants best-suited for their environment.^[3] In contrast, genetic drift produces random changes in the frequency of traits in a population. Genetic drift arises from the role chance plays in whether a given individual will survive and reproduce.

I understand that natural selection is commonly contrasted (see last two sentences of quoted paragraph above) with "random" genetic drift, but I don't understand why. That is, doesn't natural selection operate on variation caused by random genetic drift just as much as it operates on variation caused by mutation? --Unflappable (talk) 19:18, 12 March 2008 (UTC)

No, genetic drift is not a source of variation, as the article explains, genetic drift is a force that produces changes in allele frequencies, just like the various forms of selection. Tim Vickers (talk) 19:24, 12 March 2008 (UTC)

But don't you vary genetically from your parents? Isn't that variance heritable, potentially advantageous, and yet not due to mutation? Isn't creating breeds of dogs all about artificially selecting and isolating populations with certain traits that are the result of variances caused by genetic drift? --Unflappable (talk) 19:48, 12 March 2008 (UTC)

In answer to your questions: (1) not as much as I'd like (2) no (3) no.

First, you are misusing the concept of "variation." Second, everything you say about drift is true for selection as well, which only proves that they are comparable, parallel, or complementary forces. More specifically: You are saying that drift acts on a population to cause a change in gene frequencies; that is true, but the same could be said for natural selection - it too acts on a population to change (meaning, with the effect of changing) gene frequencies. Drift and selection both act on heritable traits. Dog breeders artificially select individuals from populations whose gene frequencies have been influenced by genetric drift ... and by natural selection. To sum it up: the actual gene frequencies that any force - breeding, natural selection, drift, ets. act on are themselves the result of processes like drift and selection acting on a population. But the fact that some genes, really alleles, are different from other genes (alleles) is because of mutation, that is what we mean by variation. Slrubenstein | Talk 20:07, 12 March 2008 (UTC)

Hmm. I understood that one allele was different from its twin because one comes from the father and the other comes from the mother, and they are not always the same.

By the way, genetic variation redirects to genetic diversity and the opening sentence of the sexual reproduction article is: "Sexual reproduction is a union that results in increasing genetic diversity of the offspring". That's the concept of "variation" (genetic variation a.k.a. genetic diversity) I'm using; how am I misusing it?

To summarize: The fundamental concept of evolution that normal sexual reproduction introduces genetic variation at each generation, and natural selection acts on this variation, is not conveyed in this article. --Unflappable (talk) 23:21, 12 March 2008 (UTC)

In regard to the above assertion, "genetic drift is not a source of variation", and the above clarification on the meaning of variation, I found this here:

Mendelian Genetics can only account for a majority of the genetic variations in species seen on earth. Other sources of Genetic Variation include Chromosomes Crossing over, Mutations, and Genetic Drift.

Sorry to be such a pest, but I find some of this article to be confusing, vague and perhaps incorrect. In particular, the idea that genetic variation clearly produced by normal sexual reproduction (e.g., everything that is unique about you) is somehow immune from natural selection, which the article implies, does not make sense to me. --Unflappable (talk) 20:10, 12 March 2008 (UTC)

Of course Popper is quite applicable to this concept as well. Have you ever read any of his work? Tim Vickers (talk) 20:15, 12 March 2008 (UTC)

No, I haven't read Popper. Hopefully that's not required to make sense of this article! --Unflappable (talk) 21:53, 12 March 2008 (UTC)

^ Cite error: The named reference Futuyma was invoked but never defined (see the help page).
^ Lande R, Arnold SJ (1983). "The measurement of selection on correlated characters". Evolution. 37: 1210–26}. doi:10.2307/2408842.
^ Ayala FJ (2007). "Darwin's greatest discovery: design without designer". Proc. Natl. Acad. Sci. U.S.A. 104 Suppl 1: 8567–73. PMID 17494753.

[Futuyma-1] Cite error: The named reference Futuyma was invoked but never defined (see the help page).

[Lande-2] Lande R, Arnold SJ (1983). "The measurement of selection on correlated characters". Evolution. 37: 1210–26}. doi:10.2307/2408842.

[Ayala-3] Ayala FJ (2007). "Darwin's greatest discovery: design without designer". Proc. Natl. Acad. Sci. U.S.A. 104 Suppl 1: 8567–73. PMID 17494753.

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