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Archiver > GENEALOGY-DNA > 2001-07 > 0996419482


From: "Earl Beaty" <>
Subject: [DNA] Population statistics
Date: Sun, 29 Jul 2001 09:11:22 -0600
References: <ff.97ccecc.288f446c@aol.com>


Ann,

I have now read "The Seven Daughters" and found in quite entertaining. Some
of the issues are now much clearer, but there are some puzzlements. One
concerns some of the statistical considerations you mentioned. You listed
the fraction of the current population which descended from each of the
daughters. There is a large range, and I believe you said your main concern
was whether these results could be interpreted as indicating that some were
genetically superior to others. That strikes me as a difficult question to
answer, partly because these 7 women lived at very different times. Below
is your table to which I have added the era in which each lived.

> -45000 Ursula 11%
> -25000 Xenia 1%
> -20000 Helena 47%
> -17000 Velda 5%
> -17000 Tara 9%
> -15000 Katrine 6%
> -10000 Jasmine 17%

Ursuala lived 25000 years before Jasmine, which is time for exponential
growth to have produced a huge head start in the population derby. Of
course, Jasmine had a maternal ancestor living at the same time as Ursula.
The elder Jasmine had the same opportunity for exponential growth of
descendants, but only one female line survived through the first 25000
years. Then, relatively recently her female line of descendants exploded.
In this case an explanation is offered. Jasmine's friends invented
agriculture, a technical advance which greatly benefited it's practitioners.

A consideration is that life in those early times (before -10000) must have
been very precarious, and that the exponential growth of population must
have had a very small exponent. The situation suggests that in -10000
Europe had a small population which has since grown very rapidly. Which
clan grew faster was a matter of how well the seeds were planted.

I would appreciate comments on this. I am having a hard time getting
wrapped around the idea that human mtDNA should be clumped in the way
reported. I would have been confident that mutations of Eve's mtDNA would
be spread uniformly through the earth's population. What is the force
causing the clumps?

Thanks,
--Earl Beaty

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