Re: DISCOVER/Neanderthal/Homo Sap.
Philip Reno (preno@Phoenix.kent.edu)
15 Sep 1995 20:47:58 GMT
Bearcat (bcat@netcom.com) wrote:
: Harry Erwin (herwin@gmu.edu) wrote:
: [was early H.s.s. darkskinned]
: : saying something about skin pigment. Skin color is very sensitive to the
: : amount of sunlight. It appears to go from very light to quite dark in no
: : more than 3000-4000 years, given the evidence from India.
: Thanks.
: Is the reverse true as well? Do we go from dark to light in a similar
: time-frame, and if so, why?
: - Bearcat
I have heard that it may be more "difficult" for dark skin to evolve
than it is for light skin. Too little exposure to sunlight for a dark
skinned person will result in Vit-D deficiancy that will lead to rickets.
As a childhood disease this will greatly effect one's reproductive
success.
Too much sunlight on a light skinned individual will lead to burning,
which though annoying is not life threatening. Skin cancer may
develop later in life, but that won't effect one's reproductive
success. There is the disease that results from too much Vit-D, but I
don't know who common that is. I heard that it usually occurs with
the ingestion of carnivor livers.
Is there any studies on the difference in skin pigmentation on
American Indians living in temporate and tropical regions. Those
populations in the tropic don't seem to have re-evolved dark skin in
the last few thousand years.
Also, it may be the case that the skin clor of southern East Indians,
may be a good model for Cro-Magnon skin pigmentation.
Any thoughts?
Phil
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