> I can't say that I agree with you here. I had always thought of
> "...any change in the relative frequencies of alleles in the gene
> pool of a population" as being a result of evolution. A measure
> indicating that, by some mechanism or another, evolution has
> occurred, but not itself a mechanism. Or, IOW, various mechanisms
> such as natural selection, genetic drift or whatever result in
> the changes in allele frequencies so that these changes are the
> result of evolution rather than a mechanism.
I see your point. However, whereas I agree with what you are saying, I
believe that on a fundamental level common descent is caused by changes in
allele frequencies. The chain of logic would go like this: common descent
is caused by changes in alleles frequencies which are in turn caused by
mutation, natural selection, genetic drift, etc. Think of it like this: all
the mechanisms you named could be proven wrong, yet the best explanation for
how common descent occurs would still be some form of allele frequency change.
Kevin L. O'Brien