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Re: Genetic Reversals



In a message dated 95-12-20 10:14:21 EST, Thomas_R_HOLTZ@umail.umd.edu (th81)
writes:

>I think you are talking about Dollo's Law, but that is pregenetic (i.e., was
>developed long before genetics was understood).
>
>However, genetics has shown that Dollo was incorrect.  The genome retains
>for a very, very, very long period of time the sequence (or at least parts
>of the sequence) for features long since vanished in the phenotype.
>
>

Usually, during vestigialization the genes for encoding the particular body
part are suppressed by other genes, not eliminated from the genome. The point
of Dollo's Law is that when a body part is lost through vestigialization,
natural selection has ceased to work on it, and it is very unlikely to return
spontaneously.