Re: Adaptationism's Lessons (was Re: Evolution, "adaptation")

Paul Gallagher (
15 Sep 1996 17:28:26 -0400

>What I think the Williams/Dawkins concept of adaptation requires is that,
>>if there is a selection bias for a unit of hereditary change (including
>>cultural units), *then* it must be an adaptation by definition, and what

One minor point, but one I think we all could agree on, is that it isn't
possible always to speak of the fitness of an allele (a unit of
hereditary change). A classic example is the hemoglobin S gene. Homozygosity
for a particular allele of that gene causes sickle cell anemia.
Heterozygosity, with one allele of the normal type, confers a fitness
benefit: resistance to malaria. Since the heterozygous condition is more
fit, we can't really speak of the fitness of individual alleles. By
William's definition, the sickle cell allele would be considered an