Hello List,
We have final results (markers 38-67) returned for #N9852, the original, first
member of the CARRICO project, who descends from James T. CARRICO & Joanna
KEITH, of Charles Co., MD, and Washington Co., KY:
http://dgmweb.net/genealogy/DNA/Carrico/CarricoDNA-results.shtml#J2
He is now a 66/67 match with #62917, who descends from James CARRICO & Elizabeth
CLEMENT of Charles Co., MD; and he is a 65/67 match with the descendant of Abel
CARRICO & Nancy Ann KENT of Charles Co., MD, and Grayson Co., VA. These are
very close matches, and they establish without a doubt that these individuals
descend from a near common ancestor. If all we wished to prove is that these
CARRICOs descend from the same progenitor (presumed to be Peter CARRICOE, the
1674 immigrant to Maryland), then we've accomplished that goal. However, the
tightness of these matches also poses a problem...
If we would like this DNA testing to resolve issues with regard to identifying
(separating) the descendants of different sons of the progenitor, these very
close results suggest that 67 markers will likely not be enough to accomplish
the needed separation. Not that we should expect all lines to be distinct
because it is outside the realm of probability that each son or grandson of the
progenitor would conveniently have a different mutation. Mutations simply don't
happen that often. What we can hope is that each descendant tested possesses
some mutation, literally "along the line" (if not in the son, then the grandson
or great-grandson), that will distinguish him from other descendants; and we do
have that situation in the project at this point. While our three testees match
65/67 or 66/67, they do not match 67/67. Each of these three members still has
a unique haplotype at 67 markers.
What we can do to increase the separation of project members is to test more
markers, beyond the standard 67. FTDNA has some "advanced" STR tests (ones
they
acquired when FTDNA purchased German company, DNA-Fingerprint), which can be
taken. Plus there are some additionsal STR markers tested by other companies.
I will compile and post a list of these markers for those who want to "max out"
their testing. We can also expect that additional useful tests will become
available in the future. I qualify this with the word, "useful," because while
there are many markers that can be tested, most of them are simply not variable
enough to be useful in "genealogical time," that is, in the past ten or twenty
generations. The difficulty in the quest for more markers is finding ones that
are variable enough to be useful with such a relatively few generations.
Diana