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Archiver > GENEALOGY-DNA > 2003-12 > 1071003255


From: "Peter A. Kincaid" <>
Subject: Re: FW: [DNA] Probabilities of 37 markers up to 174 markers
Date: Tue, 09 Dec 2003 16:54:15 -0400
References: <002001c3be7c$89a15660$8a0aa8c0@William><002001c3be7c$89a15660$8a0aa8c0@William>
In-Reply-To: <6.0.0.22.0.20031209105014.1057e9a0@wells.org>


>The labs in establishing the markers they are using have focused on markers
>that are reliable and don't experience rapid mutation but do have some
>typically long term variance so that the resultant patterns will be
>predictable within families. That is good and certainly has served us well
>so far. What they missed was the inclusion of a few fast(er) changing
>"junk" markers to help us sort the branches of a family out from the others.


How will that help? Let's say that we have a 26th marker
which mutates once every 2 generations. Starting with
the ancestor who was a 15 (for example) 6 generations
ago then of his 7 lines who would expect 3 mutations in
each line. However, one still must remember that there
will be some lines which did not mutate or mutated only
once or twice. Let's say lines A and B mutated 3 times;
C and D mutated twice, E and F mutated once, and G did not
mutate. You could easily get.

A14 (ie. up two to 13 and back 1 to 14)
B16 (ie. to 14 and then backwards 2)
C15 (ie. to 14 or 16 and then back to 15)
D13
E14
F16
G15

You have decendants of A and E thinking they are of the
same line in addition to B and F; and C and G. Now that
will surely mess things up. Furthermore, you will also
get the odd non related 12s and 18s who mutated into
your family. Sounds like a mess to me.

My preference is to stay with the slow movers. If we
get one mutation, then we have a new line which we can
feel more comfortable that is truly a new line. It also
help to keep the non relatives out.

My food for thought!




Peter A. Kincaid
Hampton, NB, Canada

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