On Fri, 14 May 1999, Nieft / Secola wrote:

> Do you mean that there is no evidence for mutations, or is it the random
> part that is unsupported?

Neither.  I mean that there is no evidence that mutations are the
source of variation within a species.

> It may be that what are considered mutations are really the activation of
> previously "dormant" genes.

Indeed.

> Perhaps selective pressures are acting on less
> of an actual mutation, than a "mining of the baggage" already contained in
> the DNA.

That's a distinct possibility.

> Neotony is one example. The ability for, say, lactose digestion simply
> remains--the genetic basis for it is not "switched off".

Lactose digestion may or may not be an instance of neoteny, given
the ambiguity of that term.  If the ability to digest lactose
efficiently is not lost in a fraction of the population, and
there is selection pressure in favor of that characteristic, then
it will probably increase in the population.  No mutation is
required to explain this.

Todd Moody
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