Talk:Genetic drift

To Do

• Generalize example to differing initial frequencies
• Generalize example to combined selection/drift
• Formula for probability of drift
• Formula for expected (magnitude) of drift
• Role in extinction, fixation, substitution
• Probability of substitution
• Balance between mutation influx and extinction/substitution
• Neutral evolution
• Drift -> divergence -> finds new points where selection exists
• Gene duplication -> more drift -> new function
• Loss of unused traits (example: sight in dark cave)
• Diffusion models of genetic drift

Article review

It has been a while since this article was reviewed, so I took a look and noticed lots of uncited statements, including entire paragraphs. Should this article go to WP:GAR? Z1720 (talk) 03:12, 22 March 2026 (UTC)

The article looks good to me. Genome42 (talk) 20:10, 22 March 2026 (UTC)

• @Genome42: Are you willing to address article concerns? Good articles should adhere to the good article criteria, and I think this article needs to resolve the uncited statements per criterion 2b. Z1720 (talk) 03:35, 28 March 2026 (UTC)

  I’ve changed my mind. I now think that the article does not merit good article status but not for the reason you stated. I think it contains misinformation and leaves out some important facts about random genetic drift.

But returning to your specific objection, can you give me a specific example of statements that need a citation and what kind of citation you would like to see? Genome42 (talk) 12:21, 28 March 2026 (UTC)

• @Genome42: I added citation needed templates to the article. After taking another skim, I also think the lead will need to be expanded if the article remains the current length, as there are major aspects of the article missing from it. Z1720 (talk) 20:10, 28 March 2026 (UTC)

  • @Z1729:: The standard requirement for citations states that, "All content that could reasonably be challenged ... must be cited."

  You have bombed the article with numerous citation needed insertions but I fail to see how some of the facts you question could be "reasonably challenged." They all seem like standard textbook stuff to me.

  Are you knowledgeable about this subject? Could you give me some examples of "reasonable challenges" that you think are being ignored? Please pick any one of your citation needed examples and explain the reasonable challenge.

  Also, the introduction to a lengthy article should just set the stage by introducing the topic and the gist of what the article is about. We don't need to insert a precis of every topic covered in the body of the article. Genome42 (talk) 20:45, 28 March 2026 (UTC)

• @Genome42: Sorry that I did not get this ping. "Standard textbook stuff" still needs to be cited on Wikipedia per WP:V, as it can be challenged. An editor does not have to be knowledgeable in a subject in order to challenge a claim. In fact, I believe it is better if they are not knowledgeable, as they can point out places where subject matter experts might overlook because they fill in the gaps automatically. As for the lead, it should be "a summary of its most important contents." (WP:LEAD.) I do not think this version of the lead accomplishes this. Z1720 (talk) 02:17, 7 April 2026 (UTC)

  I love it when Wikipedia editors tell us that their lack of knowledge makes them an expert. Genome42 (talk) 04:11, 7 April 2026 (UTC)

GA Reassessment

Lead

@Genome42 you removed the mention of population bottleneck and founder effect from the lead. Given that there is a whole section on them, and leads summarize the body, can we work to make a one sentence summary you feel is accurate? CaptainEek ^{Edits Ho Cap'n!}⚓ 17:46, 11 May 2026 (UTC)

There are two separate issues here.

1. There's a growing tendency to expand the leads to science articles by mentioning everything that appears in the main body of text. We should try and resist that trend because it defeats the purpose of an introduction.

2. Bottlenecks and founder effects are not, strictly speaking, examples of random genetic drift. They are unique one-off events that alter the allele frequencies of a new small population. They are often grouped with random genetic drift because they give rise to non-adaptive changes but they aren't an integral part of standard population genetics.

Random genetic drift is usually described as a slow ongoing process that gradually changes allele frequencies. It's effect can be drastically affected by bottlenecks and founder effects and that's what should be described in the main body of the revised article. It doesn't merit a mention in the introduction to an article on random genetic drift. Genome42 (talk) 19:14, 11 May 2026 (UTC)

As to 1: As a frequent writer of leads, a lead is not an introduction. WP:LEADFOLLOWSBODY. The lead begins with a definition and then summarizes the article. A person should be able to have a general overview of the article from the lead alone, and then they can read the article for further detail.

As to 2: so I think you're saying the body is incorrect? Do you suggest the material shouldn't be covered here? What in particular is the article getting wrong? CaptainEek ^{Edits Ho Cap'n!}⚓ 19:59, 11 May 2026 (UTC)

Allele

It's important to remember that genetic drift is a change in the frequency of alleles due to chance. An allele is any variant in the genome. Alleles can be found in genes, in regulatory sequences, in origins of replication, in centromeres, in telomeres, and in junk DNA. Alleles are not confined to genes - this is a common misconception.

Much of the work involving genetic drift has to do with constructing phylogenetic trees based on changes in allele frequencies in different species. We now use whole genome sequences to construct those trees so in complex organisms (e.g. animals) the vast majority of those allele are neutral and most are located outside of genes. Genome42 (talk) 14:09, 13 May 2026 (UTC)

I think we're on the same page about that? Is there a particular change you suggest anywhere? I know I changed the lead to "genetic variant" rather than "genome variant", because genome variant implies whole genome. While while genomes are relevant in drift, I don't think we can say that drift is always about a whole genome. If you still feel it's inaccurate we could just link to allele, or we could say "genetic or genomic variants" CaptainEek ^{Edits Ho Cap'n!}⚓ 15:15, 13 May 2026 (UTC)

A gene variant is a variant within a gene so that change was misleading. A genome variant is a variant anywhere in the genome. I don't what you mean by "genetic variant." Just "allele" would be better but the idea was to emphasize that ALL alleles were subject to drift and not just gene alleles. Genome42 (talk) 19:40, 14 May 2026 (UTC)

Just allele is fine by me so I've changed it. CaptainEek ^{Edits Ho Cap'n!}⚓ 20:09, 14 May 2026 (UTC)