GENBRIT-L Archives

Archiver > GENBRIT > 2006-01 > 1137840168


From:
Subject: Re: Most recent common ancestors
Date: 21 Jan 2006 02:42:48 -0800
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>
In-Reply-To: <1137762393.515829.90200@g47g2000cwa.googlegroups.com>


wrote:
> > What about using actual genealogy data ?
>
> Hard to prove anything with it. Consider for example the Icelandic
> genalogy database. It has pretty much the complete family trees for
> every inhavitant of that country, as far back as records exist.
>
> If I exclude recent immigrants, with no Icelandic ancestry and adopted
> people where information on biological parents is not available, I can
> make a few interesting observations.
>
> The current population is a little over 300.000. If I pick any two
> currently living people at random, I have to go back 6.5 generations on
> the average to find a common ancestor. I have never had to go back
> more than 10 generations. This means that *a* common ancestor for any
> two people in this population can be found 200-300 years ago. If I
> look for the most recent ancestor, I have to go back only 500 years to
> find one - a Catholic bishop, who had 5 or 6 children with his
> mistress.
>
> 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.

This thread: