Archiver > GENEALOGY-DNA > 2005-06 > 1119982045

From: Doug McDonald <>
Subject: Re: [DNA] Who is the ancestor??????
Date: Tue, 28 Jun 2005 13:07:25 -0500
References: <>
In-Reply-To: <>

> In a message dated 6/28/2005 1:33:43 PM Eastern Standard Time,
> writes:
> #456 #570 #CDY b TIME:
> 1. 15 20 36 1893-1967
> 2. 16 20 35 1830-1890
> 3. 16 20 36 1792-1835
> 4. 16 21 35 1777-1852
> Julia,
> I'm sorry; what is known: these have common surnames, without any known
> documented relationship. Not much to go on; it appears #4 is a mutation of #2,
> and #1 is a mutation of #3. Do we need more participants to answer who the
> ancestor was?
> Larry

I assume those are the oldest known ancestor, not the person tested. As
I said before, in reality we have to assume that what you really mean is
that these are FTDNA 37 marker sets that otherwise match perfectly.
Also, as I said before, we can guess pretty well what a purported
common ancestor would have as haplotype: 16, 20, 36. Given only what I
knew before, you could expect the most probable time for a common
ancestor for all four would be 8 (Actually 7.7) generations. That is, on
average 8 generations would have passed in all four lines if they arose
from 4 brothers. It would be farther back to the overall common
ancestor if you have two sons of the common overall ancestor, and those
lines later branched. The overall most probable length of the whole
tree is just 4*7.7 = 31 generations.

Now, in this post, you have given us some more info .... that they don't
connect back at least to 1860-ish. That's 4 or 5 generations. I don't
have the exact calculation done, but just looking at graphs, that would
push the overall, for all four, most probable common ancestor back
to about 10 or maybe 11 generations ago.

The DNA says that you certainly should be rummaging around in old
paper for a connection.

Especially if the name is not Smith.

Doug McDonald

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