Talk:Evolution/Genetic drift

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Moved from Talk:Evolution --Brion 23:16 Jan 19, 2003 (UTC)

Genetic Drift

I deleted a paranthetical characterizing genetic drift as "random." I think the use of this word is misleading. It is correct that drift is random in the sense that it is non-teleological (although the same could be said for natural selection -- it is functional but not because of any greater purpose). But "random" also suggests "arbitrary" and "patternless," when genetic drift is a statistically understandable process. Slrubenstein

I have been going over "drift" and realize I may be wrong about drift and randomness. So I would appreciate it if someone could incorporate into the article more discussion of this/clarification. What is the role of sampling error here? Also, could someone acurately describe the founder effect here? I think the crucial thing is that this article give a clear account of the other processes involved in evolution besides natural selection... Slrubenstein

I think that it is easy to understand what is meant by "random" in this context, but you are right that the wording isn't very precise. Would "stochastic" be better? Maybe we should forget that and get to the real point; in situations of "genetic drift", the cause of selection is not related to anything that is inherited. adam

The second paragraph on "genetic drift" is very misleading, and suggests that Stephen Jay Gould doesn't believe in evolution at all (which in fact, he's a strong proponent of). David Myers

Hi SLR - I don't think it's so misleading as to require removal. SJG DID believe that natural selection was overrated, and that genetic drift is important... actually I don't really see what the problem with the paragraph is in general. I think it just says what Gould said - natural selection can't adequately explain the development of many traits. Graft

well, okay -- it is easy to revert. But it really needs substantial changes and I propose just re-writing it. Drift is a kind of sampling error and is in no way inconsistent with natural selection; the importance of drift depends heavily on the size of the population and can't be treated as an independent variable. And DM's comment is correct: the passage made Gould look like an anti-evolutionist. In fact, Gould's books are FULL of articles explaining how weird physical features may have been selected for. In fact, I think the SJG example is a poor one: all students of evolution understand that natural selection does not explain everything and that drift is important. Gould is not a tall unique or even extreme in this regard. It is true that he has distinguished himself from others in some ways (e.g. through the theory of punctuated equilibrium, and his notion that evolution acts on species and not just individuals, or even genes) -- but this in my opinion is just not the place to single Gould out. Slrubenstein