RE: paleonet peppered moth, out of Africa (only a question forcuriosty, all others please delete)

[Leigh Van Valen <leigh@xxxxxxxxxxxx>]

William Durham (I think) has considered this problem from the 
perspective of a lightening of skin color being advantageous in areas 
where sunlight is in sparse enough to make vitamin D a resource often 
in short supply.  He notes that 'eskimos' have an abundant 
alternative source of vitamin D in their diet of fish and 
(fish-eating) seals.
  -Leigh

>Hi all,
>
>I have a possible answer to Peter's question:
>
>-----Original Message-----
>From: paleonet-owner@nhm.ac.uk On Behalf Of Peter Paul Smolka
>Sent: Thursday, May 05, 2005 5:48 PM
>To: paleonet@nhm.ac.uk
>Subject: Re: paleonet peppered moth, out of Africa (only a question for
>curiosty, all others please delete)
>
><snipped>
>
>It is often said that Europeans got pale for reasons of paleoclimatic
>conditions in the Pleistocene/Holocene.
>
>On the other hand (here the question): The Asians (Siberians,
>Indians (in the sense of North America) and Inuit ("Eskimos")
>experienced similar conditions (also ice margins and thus precipitation,
>lack of insolation in North America).
>
>As the insolation was most likely comparable: Why didn t they get pale?
>
>And: Why did they get a different skin and some (see research the Wella
>company had to do) different hairs?
>
>Did they for example get earlier or later as we out of Africa?
><snipped>
>
>-----End Original Message-----
>
>
>To even ask the question this way is to assume that all people, everywhere,
>will always change in the same direction given roughly similar environments.
>However, species are made up of many different populations, and each
>population will experience different random mutations.
>
>I would think that mutations for low melanin levels just happened to occur
>and successfully persist in a population of people living in Europe.  Hence,
>the relatively melanin-deficient skin of many Europeans is just a little
>historical quirk, an odd little change that "just happened to happen" in one
>population.  It is *not* a trait that *has* to happen in any high-latitude
>group.
>
>Of course, this is just my hypothesis -- anyone know of evidence to support
>or refute it?
>
>Peg Yacobucci
>Associate Professor
>Bowling Green State University
>Department of Geology
>190 Overman Hall
>Bowling Green, OH  43403
>(419) 372-7982