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From: Denis Beauregard <>
Subject: Re: Most recent common ancestors
Date: Sat, 21 Jan 2006 11:29:19 -0500
References: <1137338990.456458.231910@f14g2000cwb.googlegroups.com> <mo4ms15t5bs77ev0ds8bhs690882gdmb15@4ax.com> <dqf5c5$rl4$1@newsg1.svr.pol.co.uk> <dqff7p$afe$1@eeyore.INS.cwru.edu> <1137418196.188867.258490@g43g2000cwa.googlegroups.com> <dqgcjb$bt0$1@eeyore.INS.cwru.edu> <b3gns1hvb0f8a24rt35mambfro31q1co61@4ax.com> <1137762393.515829.90200@g47g2000cwa.googlegroups.com> <1137840168.896953.201470@g47g2000cwa.googlegroups.com>


Le 21 Jan 2006 02:42:48 -0800, écrivait dans
soc.genealogy.medieval:

>>
>> While this is slightly interesting, it is also fairly irrelevant for
>> this discussion - here as elsewhere genalogical records simply do not
>> go back far enough to actually prove anything about the original
>> subject.
>
>Not at all - I think you are much too modest in your claims. The fact
>that the common ancestor for a population of 300,000 (roughly 2^18)
>lived 500 years ago (roughly 18 generations) is a very interesting data
>point.

Exactly my thoughts.

Another point: Quebec, with roughly 6 millions of descendants of the
French colony founded in 1608, is close to saturation in 400 years.
So, that 500 years to saturated completely a sizeable local population
with a common ancestor can be a point to consider. If you need 500
years for the most recend common ancestor in a somewhat local and
monolithic colony (same language, same religion, relatively small
area), then you need a lot more so that any living person of that
time be an ancestor of every living persons. It could be 700 or
even 1000 years.

You add to that the fact that large migrations were not common. You
have the barbars at the end of the Roman empire, for example, the
crusades, the expansion of the Muslim lands, the invasion of the
New World. I found that about half of Quebec immigrants had
descendants after 200 years. I don't know if this is a constant,
but if it is, after about 700 years, 1 person out of 10 would
have a descendant. For 2000 years, it would be 1 person out
of 1000 if we don't account for the saturation and population's
growth. So, you must have a sizeable migration if you want to
have a common ancestor to many persons from remote places.


Denis

--
0 Denis Beauregard -
/\/ Les Français d'Amérique - www.francogene.com/genealogie-quebec/
|\ French in North America before 1716 - www.francogene.com/quebec-genealogy/
/ | Mes associations de généalogie: www.SGCF.com/ (soc. gén. can.-fr.)
oo oo www.genealogie.org/club/sglj/index2.html (soc. de gén. de La Jemmerais)

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