Archiver > GENEALOGY-DNA > 2001-07 > 0995493373

From: Alan Savin <>
Subject: Re: [DNA] A DNA genealogical mystery
Date: Wed, 18 Jul 2001 21:56:13 +0000
In-Reply-To: <005501c10f0e$f3da18c0$222bebd0@oemcomputer>

Dear Mary,

I find this a fascinating story and a good demonstration of the potential
of DNA for genealogical research.

Firstly as to your statement that two people with a perfect match would
normally have the same surname. Perhaps you have been misled into thinking
this, as on this list, people with the same surname are looking for a match
to start with. This question and other related ones have been looked at by
some of the leading geneticists in the world and their conclusion is: this
is not a straight forward question to answer. To start with how common in
the RELEVANT population, is the haplotype we are referring to? I feel we do
not have enough data to even answer this initial question. The best guess
as to how many loci are needed for a unique surname haplotype is now 50

Regarding the timing of the event, genetically any dating is still
dependant upon several variables and is an "average" figure. Not all 12/12
matches will have the same "average" timing for the earliest common male
ancestor. I am not convinced by the statistical methods used by geneticists
when we are talking of the time frames genealogists work in.

It is this type of questioning that we "genetic genealogists" on this list
should start to seriously consider, for this field to now advance. I have
only just scratched the surface of the issues here but the good news is
that in the future we will be in a much better position to answer these

Any other comments from the list?


>I have an intriguing DNA-related genealogical mystery involving
>Allisons and
>Leightons who lived in the Barrington, NH area in the last quarter of
>the 1700's. It involves DNA analysis results and I'm wondering if some
>of the members of this mailing list who are so much more knowledgeable
>about DNA research than I would be willing to make a speculation about
>whether an Allison/Leighton connection occurred 220 years ago or at some
>other unknown earlier time in history.
>A male cousin of mine whose last name is Allison and a man whose last
>name is Leighton recently had their Y-chromosome DNA tested for
>genealogical purposes by the same DNA testing company (Family Tree DNA).
>They don't know each other, but they have been informed by FTDNA that
>their DNA matches
>perfectly, which means that they have a common male ancestor. Normally
>two people with a perfect match would have the same surname, of course.
>Mr. Leighton sent this interesting "family story" which may explain how
>his DNA matches my cousin's DNA:
>"In 1780 an infant boy was left on someone's porch, probably in
>Barrington, NH. One family story is that as it was "late on" in the
>evening, he was given the name Robert Laton. Another story was that he
>was left on the doorstep of a Deacon Leighton and his barren wife.
>Other rumors were that the old deacon was his biological dad!"
>My theory is that the baby's biological father was an Allison who
>descended from the same male Allison ancestor that my cousin and I
>descend from. The baby was accepted and raised (adopted?) by the
>Leightons and was given their surname which would account for the two
>men with different surnames having the same DNA markers.
>I'm assuming that the baby was born to an unwed woman. Mr. Allison was
>probably "out of the picture" by the time the baby was left on the
>Leighton's doorstep. An out-of-wedlock birth in the 1700s would have
>been a great social stigma for the young woman. She couldn't raise the
>child herself. She probably thought the deacon and his wife could make
>a good home for the baby.
>In order to determine if my theory has any validity, I needed to find
>out if any Allisons lived in or around Barrington, NH. in 1779 and
>1780. An Abraham Allis signed The Association Test for Barrington, NH
>in 1776. I have learned that there was an Abraham Allison listed in
>the 1790 Barrington census. This could have been the same person. I
>have also been informed by a Barrington researcher that there were
>several Ellis and Ellison families in Barrington at that time. Ellison
>is a common variant spelling of Allison in early records.
>The Allison/Leighton connection could have occurred in NH in 1780. Of
>course, it could have occurred at a much earlier time in history also.
>I will appreciate all comments. Does a 100% match indicate the
>likelihood of a fairly "recent" nonpaternity event (i.e. 1780)? Could
>the nonpaternity event have occurred much earlier than that and still
>both men could have a perfect match?
>Mary Allison Yonan
>Search over 1 Billion names at!

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