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Archiver > GENEALOGY-DNA > 2004-01 > 1073075981


From: "Rik Vigeland" <>
Subject: RE: [DNA] Question for you scientists!
Date: Fri, 2 Jan 2004 12:39:41 -0800
In-Reply-To: <3FF5C853.000001.01856@computer>


The simple answer is, when you have two X chromosomes,
they swap bits of information back and forth. And
actually, ALL your matched chromosomes do this. It's
only when you have an X and a Y that there is no
swapping.

In other words, the X chromosomes you got are no longer
identifiable as "Mom's" and "Dad's". That's why there
is the Mitochondrial DNA test, because that comes ONLY
from Mom. Y comes only from Dad. Anything else gets
mixed over the generations. Testing an X can't tell you
which of your grandparents it came from; if you're a woman
it came from ALL of them.

Rik Vigeland
Canby, Oregon

>-----Original Message-----
>From: Debby Peare [mailto:]
>Sent: Friday, January 02, 2004 11:37 AM
>To:
>Subject: [DNA] Question for you scientists!
>
>
>
>I've been watching the discussion of
>the different tests and results of the
>DNA "Y" chromosone for awhile now.
>And, I think it's great! :-) But why aren't
>there any tests for the "X" chromosone?
>
>Males are "XY"...the "X" from Mom,
>the "Y" from Dad. And it's the "Y"
>that is tested.
>Well, females are "XX"...first "X"
>from Mom, second "X" from Dad.
>So, tell me, why can't that second X
>be tested as it has to be different from
>Mom's X, or you'd be a clone of Mom!!
>And, why aren't any tests being done with
>the first "X"....Mom's contribution?
>Seems to me that Mom has SOMETHING
>to do with the offspring's DNA ethnicity,
>and makeup, doesn't she?
>Looks like maybe we're being a wee bit
>chauvinistic in research here, aren't we?
>
>Warm regards from Maine,
>Debby Peare
>
>

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