GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2003-11 > 1068266325
From: Charles <>
Subject: [DNA] 25/25 marker Y-DNA test results match example with very different looking surnames -- some possibilities
Date: Fri, 07 Nov 2003 23:38:51 -0500
An example for discussion purposes:
Mr. Zimmerman has been notified by FamilyTreeDNA's computer system that
he has an exact 25/25 Y chromosome match with a Mr. Carpenter. Mr.
Zimmerman is relatively new in researching his family name and knows
little about it's origins. The question is ... is this genealogically
worth pursuing. Should he contact Mr. Carpenter or vice versa. Here are
some of the possible explanations for the Y-DNA match to consider.
1. Mr. Zimmerman and Mr. Carpenter share a common male ancestor which
predates the use of surnames. The Y chromosome on all 25 markers has
remained stable and unchanged on all the 25 markers tested for many
hundreds of years. This is certainly possible. A question for the
statisticians here. What are the odds of this happening for two direct
male line descendants of a common male ancestor who lived 1000 years
ago, assuming 20 years per generation? What are the odds of a change not
occurring in the direct male descendant lines over a time period of 1000
2. Mr. Zimmerman and Mr. Carpenter share the same Y chromosome markers
because over the last 1000 years their respective ancestors who
originally had 5 differences in their Y chromosome markers have mutated
in such a way that their Y chromosome haplotypes converged to the same
set of Y markers. This could happen. Which leads to another question for
the statisticians here. With what we know about the mutation process
over time, is it possible to compute the odds of this happening?
3. Mr. Zimmerman or Mr. Carpenter have an unknown/undisclosed adoption
in one of their direct male lines such that their Y chromosome
haplotypes match exactly, while their legal surnames do not. As an
example let us say that 5 generations ago a Zimmerman boy was adopted by
the Carpenter family and legally given the Carpenter surname.
4. Mr. Zimmerman or Mr. Carpenter have an unknown/undisclosed case of
infidelity during the Civil War period in the U.S.A., when many men were
away from home for lengthy amounts of time, such that the father of one
of the males in one of their direct lines is not biologically the absent
husband of the spouse, but said absent husband of the spouse was legally
recorded as the father. As an example let us say that Mr. Zimmerman was
away for few months during the battle of Gettysburg and subsequent
actions and upon returning discovered his wife was expecting via a
liaison with someone, who happened to be a Mr. Carpenter. Upon Mr.
Zimmerman's return, seeking to avoid scandal, the whole affair was
covered up and Mr. Zimmerman raised the child as his own.
5. Mr. Zimmerman's branch of the German immigrant family who arrived in
the colonies 250 years ago maintained the german version of their
surname, Zimmerman, but another direct male descendant branch of one of
the immigrants sons began using the English translated version of the
Anyone have any more scenarios to throw in the stew pot?