Re: puzzle of the negrito: isolated archaic populations

Gerold Firl (
16 Dec 1996 21:21:57 GMT

In article <>, (Dan Barnes) writes:
|> In article <58sf76$>, says...

|> >I'm wondering about your second point: why would you expect sexual
|> >selection to play a role?

|> It was just a side point really but it is known to have affected melanin levels in
|> Tazmania and the Andes.

Interesting - I've never heard of this. Can you explain exactly how
sexual selection affected melanin levels in tazmania and the andes?

|> >Right, though the relative importance of temperature regulation and
|> >mobility in tangled overgrowth is unclear to me; both seem to be
|> >significant.

|> But (esp. with the last point) difficult to test for - I would have thought.

Certainly, though perhaps useful analogs can be obtained by looking at
how other species react to rainforest adaptation. I believe that the
forest races of elephants are also smaller than their savanna cousins;
I would think that thermoregulatory constraints would be relatively
less important for an animal of that size. Mobility, and perhaps also
predator-resistance (there are no lions in the rainforest), would seem
to be more significant.

|> >The question then would be, from which ancestral
|> >population did the negrito evolve?

|> I would assume they evolved from African ancestors.

Ultimately, we all evolved from african ancestors. In the case of the
negrito, however, where did the rainforest adaptation take place? In
africa, or asia? Did the ancestors of the negrito migrate to asia as
rainforest-adapted pygmies, or are we looking at parallel evolution,
where an asian population converged on a similar bodyplan? It's a very
intriguing problem either way.

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me, and me alone, so sue us god. I won't tell Bill & Dave if you won't.
=-=-=-=-=-=-=-=-=-=-=-=-=-=---- Gerold Firl @ ..hplabs!hp-sdd!geroldf