There are those who tell me it can't be done, but I think it may be possible to explain why tiny amounts of inbreeding can be important.

Most people tend to think in terms of blending inheritance - and in the short run, that's a good approximation. Consider a population that's descended from Nigerians and Swedes (half and half) - two generations ago. Thinking of them as half-Swedish and half-Nigerian is a pretty good approximation. You can determine the frequencies of different gene variants just by averaging the frequencies of the two ancestral populations.

Now drop that mixed population in an isolated, sunny tropical island and wait a few thousand years. They'll be just as dark as Africans, _all_ of tehm: if you look at the genes that determine skin color, they'll be entirely African. Looking at those genes, you'd think they had no Swedish ancestry at all. If you look at other genes they still might look 50-50. The genes for light skin cllor produced fewer copies than the dark-skin genes - over time they went away, because they only really work in cloudy high-latitude countries.

if you do the math, you find that the human race would have a reasonable chance of picking up useful gene variants from the Neanderthals
with a _single_ interspcies mating: given time and an advantage of a few percent, a single copy of a gene can increase in frequency until nearly everybody has it.

Posted by: gcochran on November 10, 2006 2:38 PM

I don't see why gc thinks that the introgression was due to Neander-men raping Cro-Magwomen.

Couldn't it have been the other way around? Could such a big head have come out of a relatively small Cro-mag birth canal?

Also, I sense that the Cro-mags would have been more likely to kill the offspring, but that's just my pro-Cro prejudices speaking.

(I asked this on gnxp too)

Posted by: diana on November 11, 2006 10:40 AM

I have read countless sites about Neanderthals..seen all the documentaries and read countless reports..I have seen tools, weapons, clothing, extensive list of bones found in caves..burials, fires..BUT
Over the course of a hundred thousand years and countless anthropomorphic docudrearies..There is mention of "primitive humans" and every mention seems to suggest that "man" is small and backward..
BUT somewhere in that forestis the 100% genetically modern, artistically gifted and extremeley clever Cro Magnon..and here is a population of Animals..the neanderthals..who may be useful in many ways..Man turns everything to his own purposes
Anytime I read about a cave where there is a fire..where there are tools and bodies of neanderthals..always within the cast of man's time frame..I see that shadow flickering..but the "science" types seem to want Neanderthals "pure"..possibly to prove the theory that they were "human."
Think about the fact that here is a modern man..average height 6'4..a bit more robust than todays average but with the same exact temperment. What would be the relationship between that Man and those animals..I don't think man would see those apes as sex objects but I think there is some domesticated animal relationship being ignored...

Posted by: MM on November 22, 2006 2:33 AM






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