Archiver > GENEALOGY-DNA > 2010-02 > 1265406683

From: Wilcox Lisa <>
Subject: Re: [DNA] new world of SNPs in R1b
Date: Fri, 5 Feb 2010 13:51:23 -0800
References: <AF40B41CD3C746CCAED5F0E77B4E904D@PC>
In-Reply-To: <AF40B41CD3C746CCAED5F0E77B4E904D@PC>

Hi Andrew--

Thanks for the summary!

On Feb 5, 2010, at 12:40 PM, Lancaster-Boon wrote:

> ...The main help so far (but this will change) is that the new SNPs
> are getting
> recent enough that they can sometimes tell us that two people who
> look like
> they MIGHT be related, are NOT.

OK, so it sounds as though the SNPs in question are:
1) recently identified, and
2) the mutations themselves occurred fewer generations back than some
previously identified.

I just want to make sure I'm not completely addled. ;-)

> In other words some of the new SNPs are so recent that they can tell
> two
> people apart whose normal "STR" DNA signature (the ones we normally
> use) can
> not give a clear decision... It makes no difference in cases where
> two have only a few mutations between
> them on 37 or 67 markers. It makes no difference for people who are
> not
> close at all. It is more important for identifying distant
> relatives, or in
> fact for doing the opposite, for telling you who is not one.

So, if you have a very close or exact match between two Rib haplotypes
at, say, 37 markers, a significant mismatch between them in the newer
SNPs would indicate, at the very least, no recent connection?

> ...They look at the TMRCA numbers, which are EXTREMELY rough
> numbers, think that the
> TMRCA number was the point of the exercise, and then give up and
> tell their
> relatives not to bother.

Yes, I've seen that in the surname project with which I'm involved.
With the best will in the world, it can be difficult for project
directors to communicate the nuances. It doesn't help that so many
base their expectations on what they absorb from crime-scene television.

> ...This is where the paper trails and the DNA trails really start to
> map each other out and have a
> "conversation" in front of you.

I love this expression! I look forward to the day I can have the
experience. ;-)


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