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Archiver > GENEALOGY-DNA > 2006-10 > 1160320015


From: Vincent Vizachero <>
Subject: Re: [DNA] Genetic "proof" and numbers of ancestors
Date: Sun, 8 Oct 2006 10:06:55 -0500
References: <000801c6ead9$28bf3420$6401a8c0@HP>
In-Reply-To: <000801c6ead9$28bf3420$6401a8c0@HP>


On Oct 8, 2006, at 7:56 AM, Diana Gale Matthiesen wrote:

> You can use DNA testing to support your pedigree "beyond a
> reasonable doubt,"
> but that proof can never be absolute.

Thankfully, this concept should come naturally to any experienced
genealogist. Anyone who has learned that birth, marriage, military,
census, death, and probate records can never provide absolute proof
of the relationship they purport to demonstrate will have no trouble
with the notion that the same is true of DNA.

One advantage of DNA evidence over other types of evidence is that
the degree of uncertainty around conclusions reached from DNA
evidence is estimable. This is generally not true with paper trails.

Another advantage of DNA evidence is that a well designed test might
establish that some alternative plausible hypotheses are not
supported. If an ancestor John Smith was erroneously told that his
father was Andrew Smith, that error will show up on all the available
paper records if he and his family believed it or chose to perpetuate
it. No amount of conventional cross-checking will raise any doubts
about the relationship.

A well-designed DNA test, on the other hand, might establish that
John's father was not Andrew Smith, nor Andrew's brother Robert, but
rather Andrew's neighbor Thomas Wilson. As Diana points out, this
will require a number of tests (presumably at least a few for each
line of descent) but it is possible.

Vince

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