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Archiver > GENEALOGY-DNA > 2005-06 > 1118177094


From: (John Chandler)
Subject: Re: [DNA] DNAPrint strikes again!
Date: Tue, 7 Jun 2005 16:44:54 -0400 (EDT)
References: <1394-42A5190E-334@storefull-3138.bay.webtv.net>
In-Reply-To: <1394-42A5190E-334@storefull-3138.bay.webtv.net>(Circles54@webtv.net)


Allen wrote:
> I may be dense, but how can a person have a negative percentage
> contribution from a source? I've blinked my eyes at this several times,
> so I have to ask. It seems that you would be saying the contribution is
> less than none.

The point is that the reference populations in the DNAprint test are
not sources, but rather mathematical constructs that are hoped to be
good approximations to sources. As it happens, most of the markers
used are far from saturated in the reference populations. In other
words, an allele that points toward population A may still be present
at only the 70% level in population A -- or even less. That means
there are lots of individuals who are "super-A" by virtue of having
two copies of that allele. Combine several such markers, and you get
someone who is distinctly more than 100% A (and therefore less than 0%
something else).

John Chandler


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