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Archiver > GENEALOGY-DNA > 2011-12 > 1322846121


From: David Faux <>
Subject: Re: [DNA] No matching segments
Date: Fri, 2 Dec 2011 09:15:21 -0800
References: <mailman.285.1322812844.24128.genealogy-dna@rootsweb.com><D322CFEE-9362-4387-8C0C-935136DC887B@charter.net>
In-Reply-To: <D322CFEE-9362-4387-8C0C-935136DC887B@charter.net>


Well it would be very very unusual (really only theoretically possible)
that someone would share zero with a first cousin. I have never known of
this occuring. It would be a red flag for a NPE.

I share 14% plus (versus the 12.5% expected) with my first cousin. In my
study of 31 of us all related via descent from Adam Young (Johann Adam
Jung) b. 1717 Schoharie NY d. 1790 Haldimand County Ontario Canada,
everyone "behaves" within predicted bounds. There are of course some
oddities. My uncle does not match his third cousin at all (zero), which
happens about 10% of the time. However I match this same fellow who is my
third cousin once removed at 0.90%, 4 segments, 66 cM. My first cousin
matches him only on the X chromosome, one segment, 15 cM.

I match my grandmother's second cousin (my second cousin twice removed) at
1.17% on 7 segments (and he is only a half second cousin to my
Grandmother). This is on the high side, but we have 6th cousins, sharing
at 40 cM, whose MRCA is the above Adam Young - and a whole lot of 6th
cousins who do not match each other.

To repeat, any zero match found in someone who is a second cousin once
removed or higher brings to the fore the rather high likelihood that the
two of you are not biologically related.

David K. Faux.

On Fri, Dec 2, 2011 at 4:59 AM, John Lerch <> wrote:

> Mary Alice,
> You totally miss the point. There is a chance (albeit a very small
> one) that you have ZERO matching segments with a TRUE BIOLOGICAL
> SIBLING.
> Over on the Genetic Genealogy Forum, David Faux has a proven (by
> comparing DNA to the relevant proven matching persons) cousin (1st
> cousin I think) to whom he has ZERO matches!!! So it does happen--
> Just because you have no matching segments doesn't mean you're (not
> "your" as in both your posts) not related.
>


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