Part of this disagreement seems to stem from a detachment of ecological processes (death and reproduction) and resulting evolutionary patterns. Various ecological processes act in a non-random ways to remove phenotypes (and indirectly genotypes) from populations. I am hesitant to reserve the term natural selection for only those occasion when there is subsequent response to selection. Doing so unnecessarily entangles selective pressures (ecological processes or events that affect reproduction and mortality in a non-random fashion) with mechanisms of inheritance (primarily genetic variability).
Imagine the case where you have two phenotypically identical populations that have different underlying genetics. If these populations have different heritabilites, application of the identical selective pressures could lead to dramatically different outcomes. In this scenario only the responses to selective pressures would differ. It would seem inconsistent to me to retro-actively claim that natural selection was only operating in the one case where there was a response. Rather, natural selection was only effective in producing evolutionarily relevant change in one case. James J. Roper wrote: > > Natural selection doesn't "cull" but rather it "favors." And > selecting "for" something is very different than selecting "against" > something. Favoring a trait leads to adaptation. That is, those with > a trait leave more descendents. Even so, it is not that simple. At > any rate, John Endler does a wonderful job of clearing things up with > "Natural Selection in the Wild" and I highly recommend it for anyone > who has not read it, and, don't forget, "The Extended Phenotype" by > Dawkins, that should also be required reading. Perhaps I should have not said the dreaded g-word so casually. Empirically speaking natural selection seems most effective operating within a population. However, theoretically speaking, there is no reason to think it can't operate on higher scale entities. Though we may both wish it to be true, we are unlikely able to commit this matter to the grave quite yet. > Besides, natural selection works with individuals, not populations... -- ************************************************************ Norris Z. Muth Department of Ecology and Evolution State University of New York at Stony Brook 650 Life Sciences Building Stony Brook, NY 11794-5245 [EMAIL PROTECTED] http://life.bio.sunysb.edu/~nmuth http://life.bio.sunysb.edu/ee/pigliuccilab/ ************************************************************
