GENEALOGY-DNA-L Archives
Archiver > GENEALOGY-DNA > 2011-02 > 1296739856
From: Jim Bartlett <>
Subject: Re: [DNA] TMRCA of 3 families in a new subclade
Date: Thu, 03 Feb 2011 08:30:56 -0500
References: <1109918832.406200.1296682819129.JavaMail.root@sz0058a.westchester.pa.mail.comcast.net><005c01cbc32a$7d3f8a30$c2482dae@Ken1><001501cbc37b$343344c0$9c99ce40$@dgmweb.net>
In-Reply-To: <001501cbc37b$343344c0$9c99ce40$@dgmweb.net>
Diana
I read your article. I believe the problem with TMRCA is that even with the most precise data, the resulting curve is still not the spike at one generation that everyone would like to see. It looks more like a low hill on a long road, and the height is relatively the same over a wide range. As a genealogist, I'd probably better spend my time looking at migration patterns, the neighbors, paging through old record books, etc.
The reason the math gives us this flat curve is because a mutation can occur between me and my Dad, or hold off for many, many generations without any changes in 67 markers. This variation in biology of the Y, can't be pinned down to one or two generations with better math.
Our ability to pinpoint a TMRCA generation will get better (he said hopefully) when we get enough of the genome tested, and work out the algorithms to triangulate that data between two individuals.
For now we agree: TMRCA is not a good tool for genealogists, in most cases.
Jim - Sent from my iPhone - FaceTime!
On Feb 3, 2011, at 3:20 AM, "Diana Gale Matthiesen" <> wrote:
>>
> Which is another way of saying what I've been saying for years: TMRCA
> is not useful in genealogical time frames, at least not in the
> detailed way (with the precision) people want it to be. I discuss the
> reasons and give an example on this page:
>
> http://dgmweb.net/DNA/y-dna-projects/TMRCA.html
>
> Diana
>
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| Re: [DNA] TMRCA of 3 families in a new subclade by Jim Bartlett <> |