Victoria,
Genealogical DNA is more complicated than sometimes
represented. Before taking such tests, I suggest
careful study via several websites offering tests,
talking with others who are involved (especially if
anyone with your name is so involved) and carefully
thinking through what you goals are.
Genealogical DNA CANNOT PROVE father-son or
brother-brother or sister-sister, etc. relationship.
In his respect, it IS NOT like DNA as depicted in the
movies and on TV or even real court cases in which
actual samples of the DNA of the involved persons is
available.
When doing genealogical DNA, samples of the DNA of our
ancestors are not usually available. There is the rare
case (like Thomas Jefferson) in which samples have
been found, but even then the best that the tests
could do was to prove that some Jefferson male who was
"available" (i.e., living nearby at the time) was the
parent of a Hemings child (if I correctly understand
the findings, and I think I do).
Genealogical DNA CAN link some currently living
individuals to the family to which they belong using
the Y-chromosome. Still, it cannot tell any particular
man WHICH individual ancestor he descends from,
although multiple tests from lines of cousins can
often refine a probable ID, supplemented with
traditional "paper genealogies."
When dealing with Y-chromosome DNA, one is ALWAYS
dealing with someone's "unbroken male line," the issue
is whose -- i.e., is it really (in my case) a CHANDLER
line or at some point in the past did I belong to
another surname only to have it changed to Chandler in
one of several ways that can happen.
The best way to verify a SURNAME DNA LINE is to test
multiple cousins. Begin with a known 2nd cousin; there
is a good chance there is a perfect match between any
two such men, although it is not impossible that there
will be small anomalies called "mutations." The more
distant the cousins, the more likely there will be
mutations, but the baseline should be there. But, for
this purpose 25 or more test markers (also called
"alleles") is HIGHLY recommended.
But, there is NO GUARANTEE that the line will trace to
ANY PARTICULAR ancestor. If someone claims to have
done so, he/she is overstating what DNA alone can do
-- it must be used in partnership with "paper
genealogies."
Joseph Barron Chandler, Jr.
Administrator
Chandler DNA Project @ <www.ftdna.com>.
--- Victoria Robinson <[log in to unmask]> wrote:
> I've been interested in DNA testing for some time.
> In fact, I will be doing
> my own in the coming weeks. I do have one question
> about when such tests
> are compared to determine whether individuals are
> descended from the same
> projenator[sp?](such as Louis Gates and potential
> cousins in last week's
> African American Lives). My question:
>
> How can one be certain that the individuals being
> used as the baseline have
> an unbroken line to that ancestor? Or does this
> approach rely on the
> concept that biological legitimacy follows legal or
> presumed paternity?
>
> I was just wondering.
>
> <html><div><P><STRONG>Victoria Robinson</STRONG>
> <BR><FONT
> color=#993399><EM>Ancestors sought: Gant,
> Potts, Goss, Wynn, Robinson,
> Kitchens, Edwards, Chambers, Dancer, Simmons, Jack,
> etc, etc,
> etc</EM></FONT></P>
> <P>"The danger to political dissent is acute where
> the Government attempts
> to act under so vague a concept as the power to
> protect 'domestic
> security.' Given the difficulty of defining
> the domestic security
> interest, the danger of abuse in acting to protect
> that interest becomes
> apparent." <BR><EM>-- U.S. Supreme Court,
> 1972</EM></P></div></html>
>
>
>
>
> >
> >Date: Sat, 4 Feb 2006 05:36:01 -0800
> >From: qvarizona <[log in to unmask]>
> >Subject: Re: DNA Article In USA Today
> >
> >Until very recently, which genealogist would ever
> have suspected that it
> >might be possible to prove/disprove family history
> via a simple
> >cheek-scrape? Fascinating... and scary, too. Do
> you suppose we'll all
> >need to take a quick course in how to read DNA
> results?
> >
> > Joanne
>
> To subscribe, change options, or unsubscribe, please
> see the instructions
> at http://listlva.lib.va.us/archives/va-hist.html
>
To subscribe, change options, or unsubscribe, please see the instructions
at http://listlva.lib.va.us/archives/va-hist.html
|
