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Archiver > DNA-R1B1C7 > 2008-02 > 1203522653


From: "David Ewing" <>
Subject: Re: [DNA-R1B1C7] Age of R1b1c7
Date: Wed, 20 Feb 2008 08:50:53 -0700


Colin Ferguson writes, "David, You could give Wimpy's ASD-calculator a spin.
It computes age based on variance from a set of haplotypes that copy and
paste into an Excel worksheet.
See:http://users.telenet.be/callmewimpy/dnatools.htm"<http://users.telenet.be/callmewimpy/dnatools.htm>;

Woah! This is impossibly cool! I was totally cowed, not as much by having to
learn a little math as by the prospects of the tedium of setting up the
calculation, but this calculator really does the job.

I've just barely begun fooling around with this and seeing what it does with
some data I have on a couple of Ewing families who have known common
ancestors 300 years ago and comparing the results of that to the results of
running all of our Ewing R1b1c7 data. If I change the default 25 year
generation time to what I take to be a more realistic 35 year generation
time (the actual average generation time in the first four generations of
our largest known family is 45 years), the "average haplotype population
age" of the largest (12-member) known family is 294 years and of the entire
group of R1b1c7 Ewings is 500 years. The two smaller (5 and 6-member) known
families have "average haplotype population ages" of 173 and 384 years,
respectively, using the same assumptions. Again, based on conventional
genealogy the actual MRCAs in each of these families lived 300 years ago,
round numbers.

Among the most interesting questions facing our project is what the
relationship may be between the progenitors of these three families, and
between these three and the progenitor of the entire group of R1b1c7 Ewings.
If I pool the data between the two of these families I think are most
closely related (the 12 and 6-member families), I get 440 years; if I then
add the data for the third family I get 468 years, and if I add all of our
R1b1c7 data, including those men on whom we don't have enough conventional
genealogy to speculate about their connection with the others, I get 500
years. I find this interesting and helpful, though I know I should restrain
my enthusiasm because of the ever-present matter of confidence intervals.

David Ewing

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