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From:
Subject: Re: [DNA] Steve Olson Article
Date: Sat, 21 Dec 2002 16:32:42 EST


In a message dated 12/21/02 1:11:56 AM Pacific Standard Time,
writes:

> I fail to comprehend the mathematics of the comment that every European may
> descend from almost everyone who ever lived in Europe before 1400 .This
> notwithstanding,my interest is not so much in the claim that one may
> descend
> from as many as 30 million people before this date, but in the supposition
> that
> people moved around Europe as much as the writer indicates.

Steve Olson has more extensive comments on this in his book "Mapping Human
History" and in an article "The Royal We" in the Atlantic Monthly May 2002:

http://www.theatlantic.com/issues/2002/05/olson.htm

He refers to a technical paper by a Yale statistician Joseph Chang:

http://www.stat.yale.edu/~jtc5/pubs/Ancestors.pdf

Now I haven't studied all of Chang's arguments and equations, but he does
mention repeatedly that his model assumes random mating in the population
(say all of Europe). I agree with you that most marriages take place within
smaller subsets of the total population (whether for geographical or cultural
reasons), so I don't think the assumption holds true.

However, Steve Olson has said that even rare exceptions, when someone marries
outside the smaller group, would create enough links to the population at
large so that eventually everyone is tied together. I suppose a computer
program could model how much random mating is required to accomplish this,
but Olson's claims go against my intuition, too!

Ann Turner
GENEALOGY-DNA List Administrator
>http://lists.rootsweb.com/index/other/Miscellaneous/GENEALOGY-DNA.html
DNA preservation kits: >http://www.dnafiler.com



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