Talk:Natural selection

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Important notice: If you wish to discuss or debate natural selection itself (as opposed to the article), you may do so at The Discussion page for Natural Selection is only for discussion on how to improve the Wikipedia article, pursuant to Wikipedia policy on talk pages. Any attempts at trolling, using this page as a soapbox, or making personal attacks, regardless of your ideological position, may be deleted at any time, as is the rule for all Wikipedia articles and talk pages.

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Good article Natural selection has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.


change ((Britain)) to ((Great Britain|Britain))

yellow tickY Partly done have changed Britain to Great Britain, but it does not need linking, as stated at WP:OVERLINKING do not link " The names of major geographic features, locations (e.g. United States, London, New York City, France, Berlin...)" - Arjayay (talk) 15:04, 15 November 2016 (UTC)

Other processes[edit]

The lead mentions that natural selection is "one of the key processes" and compares it with artificial selection. Is it intended to imply that artificial selection is the only other key process, or are there others which should be mentioned, and does the article mention what the others are if this is the case? Either it is a bit vague or I have missed the others in spite of looking for them. Also "Natural selection remains the primary explanation for adaptive evolution". This implies at least one other explanation. I assume that this excludes non-explanations. Are the other explanations mentioned in the article? It did not seem to me that they are, so either they are missing, or insufficiently obvious from the context. Or maybe I am just having a bad day... Generally an excellent article. Cheers, • • • Peter (Southwood) (talk): 13:25, 18 November 2016 (UTC)

The ambiguity, if there is any, is about whether natural selection encompasses sexual selection, or whether people are more comfortable with that as a separate process; mainly it's now included. Obviously, selection requires variation to work on, which requires mutation and recombination. Drift was once also thought important: less so in the past 20 years or so. I'll tweak the wording. Chiswick Chap (talk) 14:16, 18 November 2016 (UTC)

@Pbsouthwood: Answer is at microevolution#four processes. Artificial vs. natural vs. sexual is a downstream question, relatively speaking - the distinction is subordinate to the four microevolutionary forces. You could probably make the argument that in an artificial breeding setting, migration (called "gene flow" in that article) can be virtually eliminated, but mutation and drift are always present no matter what - cf. mutation–selection balance. Also, the influence of drift relative to selection decreases with increasing population size. For instance, a bacterial population could be so large as to be considered to be entirely governed by mutation and selection, as any mutation events lost by drift would be compensated for by recurrent mutation. Exactly what importance should be given to gene flow depends on how you define "population". HTH, Samsara 12:17, 13 January 2017 (UTC)

Thanks, everyone[edit]

Well, as you can see we've managed to get this article to GA at last. Many thanks to everyone who has contributed to the article over the years. Great work. Chiswick Chap (talk) 14:52, 29 November 2016 (UTC)


@Chiswick Chap: No strong objections to your edit, but have you made sure that it matches what the listed sources say? Thanks, Samsara 11:54, 13 January 2017 (UTC)

I paraphrased it from a source I used for the evo-devo article, I'll check it's here also. On the sexual selection image, there is surely no doubt at all that the peacock image is relevant, I'll cite it with three or four refs if need be: if you have an issue with a caption, the appropriate response is surely to edit the caption text, not to remove a good, relevant, and useful image that is certainly helpful to the sense for the first-time reader. I'll replace it now and tweak the caption: feel free to tweak further. Chiswick Chap (talk) 11:58, 13 January 2017 (UTC)
I believe there are better illustrations that the space can be used for. The peacock image seems like un-necessary puffery. An image of one peacock does not explain anything other than, "oh look, it has excessively long trains" - which the caption did not even say! Samsara 12:20, 13 January 2017 (UTC)
Nobody is puffing anything: the peacock example has been used by Darwin, Wallace, Fisher, a multitude of researchers and pretty much every textbook since, so it is certainly *the* classic example, and I'm happy to cite it as many times as is necessary, it won't be difficult. Other large and conspicuous birds with sexual dimorphism such as pheasants might have been chosen, but were not. I repeat, the cure for a less-than-perfect caption is to edit the caption. A peacock image is *exactly* the right thing here. Chiswick Chap (talk) 12:24, 13 January 2017 (UTC)
I'm trying to explain to you that citing it does not make it more useful. There are much better illustrations of the peacock that could be used if they were recreated under a free license. There is also nothing that obligates us to use the peacock just because it has been used previously. By the end of reading this article, the reader should have a good understanding of natural selection, not of the history of model organisms used. Samsara 12:33, 13 January 2017 (UTC)
Its usefulness is that it illustrates the domain, i.e. both the actual biology and the intellectual history, as citations can prove, so the bird is the right example. On which peacock image to use, that is a matter you had not raised until now, but clearly we can choose one to show the train more clearly than a flying image. I'll look one out. Chiswick Chap (talk) 12:40, 13 January 2017 (UTC)
Thanks for the edits, it's an improvement. I still think that if any illustration of the peacock should be used, it should eventually be one of the classic cutting tails, gluing tails experiment. Samsara 12:44, 13 January 2017 (UTC)
Thanks. The use of an experiment at this level sounds an odd choice to me. From Darwin and Wallace onwards, people have remarked on the selection by females, so an image of courtship and display seems exactly on the button. Chiswick Chap (talk) 13:08, 13 January 2017 (UTC)
Now you sound like you're not familiar with the experiment. It involves female choice. Samsara 13:17, 13 January 2017 (UTC)
Don't cast aspersions. I mean, Darwin et al did not see experimental results, they saw the natural results of female selection. At the top level of coverage of the topic, a single paragraph indeed, we should focus on the basic fact of sexual selection and its history, not experiments. Chiswick Chap (talk) 13:22, 13 January 2017 (UTC)
I 100% disagree with your view. An article must reflect an up to date understanding of the topic, not some 19th century perspective. Samsara 13:36, 13 January 2017 (UTC)
Nonsense, there's no 19th century perspective here. I have made clear repeatedly that there is a continuous thread of interest in the peacock's train from Darwin to the present day. Chiswick Chap (talk) 13:59, 13 January 2017 (UTC)

"focus - this is only for major sites which offer wide, objective coverage of the topic"[edit]

I don't understand the explanation for dropping two references: "focus - this is only for major sites which offer wide, objective coverage of the topic". I don't want to get into a edit war, so I'm not reverting the change, and I hope that the editor will take the opportunity to explain here, where there is more space. TomS TDotO (talk) 17:32, 14 January 2017 (UTC)

Sure. The article is fully cited, and furthermore has that luxury, a further reading section of major sources which are not cited in the text. Having further papers that are neither cited nor major enough to qualify as further reading might be thought somewhat over the top, but it's reasonable to provide links not to papers but to major sites which offer wide, objective coverage of the topic. It isn't reasonable that all kinds of other papers and websites should also be included: Wikipedia is Not a Directory, and the article requires focus in every section including this one. If a source says something important that isn't already said in the text, then it should be summarized in the text and cited as an inline reference. Chiswick Chap (talk) 17:54, 14 January 2017 (UTC)

Lead statement suggests selection/evolution at the wrong level?[edit]

The lead statement for the article is: "Natural selection is the differential survival and reproduction of individuals due to differences in phenotype." This suggests that natural selection occurs at the level of the individual, which is fundamentally incorrect per Dawkins, Richard (1976) The Selfish Gene. Selection should occur at the level of the replicator, the base unit of selection (genes, memes, etc). A more correct statement would be: "Natural selection is the differential survival and reproduction of replicators due to differences in phenotypic expression."

Dawkins continues to elaborate on this concept within The Extended Phenotype, where he discusses in depth the phenotypic expression of genes at a distance and other actions that occur outside the level of an individual. (This was written by ) (talk) 21:59, 31 January 2017 (UTC) -SA

Thank you, but I'm not sure that's what we should do. Firstly that's Dawkins's view, which by no means all biologists agree with. Secondly, the actual unit of reproduction is an individual. Thirdly, the proposed statement could not be understood by a general reader coming fresh to the subject: the start of a lead is not the place for maximum "correctness", at the expense of intelligibility, and one sentence can only convey a small part of a large subject. Chiswick Chap (talk) 20:42, 31 January 2017 (UTC)
The existing article discusses the debate over the unit of selection within Types of Selection and provides additional information in the link to Units of Selection. In any case, wouldn't the replicator still be what is selected, and the definition of that replicator as the gene or individual be the subject of that debate? Depending on how one defines the term "individual", it may or may not be a unit of reproduction. For instance, many species rely on mitochondria or other prokaryotic cells, but whether or not they are a part of the individual depends largely upon how individual is defined. Since individuals in many species can, in fact, be divided, the term is difficult to apply at the level of the organism in a technical sense. I'm not a biologist, and I understand keeping the lead simple enough that it can be understood by anyone visiting the page, but it seems as though it has been simplified to the point of being incorrect. (talk) 21:59, 31 January 2017 (UTC) -SA
It's right. See UC Berkeley's Understanding Evolution site which starts with an even simpler treatment (and goes much further on some of the related pages). It definitely talks about individuals, as well as the population they're in. Chiswick Chap (talk) 22:24, 31 January 2017 (UTC)
Interesting - I suppose it's largely about interpretation. I read that page as directly opposing the individual as the unit of selection: "The more advantageous trait (phenotypic expression of genes), brown coloration, which allows the beetle (individual) to have more offspring, becomes more common in the population (gene pool). If this process continues, eventually, all individuals in the population will be brown (alleles are reduced by selection pressure)." So the genes that produce the phenotypic expression of brown coloration would be selected against those that produce green coloration, such that they become more common within the gene pool. The individual is simply discussed as a medium through which the phenotype is expressed, not a unit of selection. -SA
Clearly things can be thought about from different points of view. However, the treatment here describes the topic in terms of individuals, population, phenotype and genes, both in the lead and in the text, as it should. The lead wisely avoids talking about "units of selection", and I didn't speak of it here either. Goodbye. Chiswick Chap (talk) 06:50, 1 February 2017 (UTC)

Agree with Chiswick Chap. "Natural selection acts on the individual" is a catch-cry used to counter the notion of Group selection. Also, what is killed or prevented from reproducing by being less well adapted is the individual, and thus it is the sum of its genetic endowment that is being acted upon, not individual genetic loci. Sminthopsis84 (talk) 06:31, 5 February 2017 (UTC)