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Archiver > DNA-R1B1C7 > 2010-07 > 1280051363


From: "Sandy Paterson" <>
Subject: Re: [R-M222] Roll Call
Date: Sun, 25 Jul 2010 10:49:23 +0100
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In-Reply-To: <4C4BB448.3050007@aol.com>


John

>
I find this question interesting in terms of DNA. Which is also why I
posted some background on McLaughlins and Dohertys recently. What
should we expect to see in different lines sharing a common ancestor
dating to about 1200-1300 AD? Or even later? How large a genetic
distance is possible? How important are shared off modal markers? How
many must be shared to constitute a valid match? I have lots of
questions and no answers.
>

I've written software that attempts to answer these questions using Monte
Carlo simulation. I haven't used the software for a while though and will
need to re-familiarise myself with it. In the meantime I'll answer as best I
can from memory.

As you know, my main interest lies in Lamont genealogy. It is hypothesised
that there was a Duinsleibhe in the line who was born around 1100AD, so I
was interested in what sort of range of gd's and number of off=modal matches
one would expect in people descended from a common ancestor in 1100AD. You
can adjust the GD answers slightly downward and the number of off-modal
matches very slightly upward for a common ancestor around 1200-1300AD.

I found that gd's were distributed around a mean of (I think) 11 or 12. Most
of them fell within the range 8-15 (maybe 80% of them) but there were some
maverick values outside of this range.

For off-modal matches (and I'm straining my memory now), a small number (but
not as small as I would have expected) had zero, a larger number had 1, and
I came to the tentative conclusion that 2 or more were worth taking
seriously.

In the context of your McLaughlin/Doherty interests, I think the smaller
range of GD's amongst McLaughlins is a-typical and that the Dohertys are
more typical. This could be explained by a partial bottle-neck in
McLaughlin, but fortunately, one that preserved some common off-modal
matches with Doherty.

I'll see what I can do in terms of picking up where I left off with the
software. If I manage to do that, it will be easy to re-run the exercise
using a shorter timespan should you be interested.


Sandy






-----Original Message-----
From:
[mailto:] On Behalf Of John Mclaughlin
Sent: 25 July 2010 04:49
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Subject: Re: [R-M222] Roll Call


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