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Archiver > GENEALOGY-DNA > 2002-02 > 1012964001


From:
Subject: Re: [DNA] Low Cost Paternity Tests
Date: Tue, 5 Feb 2002 21:53:22 EST


In a message dated 02/05/02 5:26:37 PM Pacific Standard Time,
writes:


> Hmm this wouldn't tell you the halotype (or whatever
> it is that connects you with an area and or surname)
> would it?

No, paternity tests use markers on the non-sex chromosomes (autosomes, if you
can stand another new word!). Most of your chromosomes come in pairs, one
from your father and one from your mother. You will sometimes hear the word
"diploid" from the Greek word for double.

For paternity tests, you would have two values for every marker (unless your
mother and father just happened to have the same value). If your mother has
one of the values, then your father must have the other. Of course, your
father has two values of his own, and it's a 50-50 proposition whether he
passes on the marker he received from his father or the marker he received
from his mother. This means paternity testing with father-mother-child is
pretty much of a sure thing, but more distant relationships such as
grandparents and siblings get into probabilities.

The word haplotype comes from the Greek word for single, so it implies values
which come from one chromosome. (I think it sounds a little like "half," so
that's the way I remember it.) The Y chromosome and mitochondrial DNA aren't
paired, so you automatically get haplotypes with tests on them.

There's some tutorial material on paternity testing if you'd like to delve
into this further:

http://www.biology.arizona.edu/human_bio/activities/blackett2/overview.html



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