Talk:Overdominance

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The definition given in the intro is not completely correct. Overdominance is not necessarily related to fitness. It simply means that the heterozygote's phenotype lies outside the range of the two parental homozygotes (either above or below); this may be against the direction of fitness. In addition, a heterozygote may still be fitter than either of the two parents, even if its phenotype lies somewhere between the two parents. The definition in the intro is only correct in cases where the phenotype studied is fitness itself. --Crusio 16:39, 11 November 2007 (UTC)

Wiki Education Foundation-supported course assignment

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Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 05:57, 17 January 2022 (UTC)

Unwarranted redirect

Overdominance is not just a hypothesis to explain hybrid vigor. As explained in the current stub, it is a real phenomenon. I don't think that the redirect is correct. --Crusio (talk) 22:36, 14 September 2008 (UTC)

Questionable Example

I believe that the example cited, malarial resistance, is not in fact an example of overdominance. Malarial resistance is raised in both sickle cell trait and disease. Fitness, however, is raised in sickle cell trait, because it confers both malaria protection and no associated disease. So the sickle cell gene could be said to be overdominant for fitness, but not for malarial resistance. (see PMID: 11965279) — Preceding unsigned comment added by Wjeck (talk • contribs) 17:53, 20 December 2010 (UTC)

OOps, I now see that is clear in the article --Wjeck (talk) 17:55, 20 December 2010 (UTC)

Editing overdominance Wikipedia page

Hi everyone, I'm a student and I'm in a group project that has been assigned to edit this Wikipedia page. So far we have drafted the following for this Wikipedia page: Here --AllGasNoBreaks (talk) 01:32, 5 November 2022 (UTC)

Gillespie convention deficiency

As presented in this article, the Gillespie convention (or "Gillespie model") would suffer from the obvious deficiency that it is not applicable unless the fitness for A₁A₁ individuals differ from that for A₂A₂ ones. However, also in such situations, there may be over- or underdominance.

Consider, e. g., the Pseudacraea eurytus example in the article underdominance. It does not discuss the relative fitness of the two kinds of homozygotes, except as compared to the heterozygotes. Now, if the two homozygotes have precisely (at least up to measurability) equal fitness, then they would not be covered by the Gillespie convention (since there we would have s=0 but hs≠0, in terms of the Gillespie entities). I find this problem with the convention fairly obvious; and I therefore suspect that Gillespie was aware of it, and at least made a comment about when it was applicable (and possibly also gave an alternative form in the equality case).

I would be happy if anyone with access to Gillespie's book could check what he himself writes about this. JoergenB (talk) 17:53, 23 July 2025 (UTC)