Soapy Sam
Posts: 659
Joined: Jan. 2012
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| Quote (eigenstate @ Feb. 16 2012,16:13) |
Maybe it helps to put it this way. The process, in principle, is non-tautological. But in practice, whatever survives we label as "most fit". In that sense, constrained to the dynamics of fitness as the outworking of differential survival via variable heritable traits, we do apply a tautology, or at least we say that whatever survived is the most fit. |
Well, we shouldn't label whatever survives as 'most fit', in principle or in practice. Even if we had a population of functionally identical entities (but could label the types), we would see differential survival, due to sampling alone. No individual need be inherently any fitter, nor any allele offer any boost to its bearers, for this differential to arise. Natural selection applies as a bias within this fundamental process - differential survival causally linked to the effects of alternative alleles upon mean fitness of carriers.
It remains possible that the least fit allele becomes fixed - if we ran a series of replicates, it would happen in fewer than 1/N of them (the neutral probability), but in the single replicates that we run in the 'real world', there is plenty of opportunity for fixation against the selective 'wind'. On the average and over the long run, populations adapt, because you can't buck the odds for ever - alleles contributing more to fitness will prevail. But any one individual just survived, and any gains made by a particular allele may likewise be uninformative about whether it was 'truly' beneficial to the individuals that bore it (ie it raised mean fitness relative to rivals). There are many who argue that neutrality should be the null hypothesis.
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SoapySam is a pathetic asswiper. Joe G
BTW, when you make little jabs like “I thought basic logic was one thing UDers could handle,” you come off looking especially silly when you turn out to be wrong. - Barry Arrington
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