Archiver > GENEALOGY-DNA > 2010-02 > 1265402421

From: "Lancaster-Boon" <>
Subject: [DNA] new world of SNPs in R1b
Date: Fri, 5 Feb 2010 21:40:21 +0100

Dear Lisa

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.

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.

This is possibly more important than many people realize. The testing
companies tend to promote optimistic TMRCA calculations as if genealogists
will be able to use those as precise numbers. In the long run this is
hurting all of genetic genealogy because it leads to people having the wrong
idea about the strong points and weak points of using DNA in genealogy. 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.

We should all spread the word constantly that the first results in a new
project are almost never very useful. It is most important to slowly build
up a reasonably large number of results in order to try to triangulate a
real family tree by working out which people are closely related, and then
within each such grouping to work out which sub-groups are closer. (This is
also a type of job where the advanced markers can be used very well, but
again this is not being sold or explained properly.) 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.

For projects that have been slowly building up their data, trying to work
out of which of the "grey zone" possible matches are real is often a big
issue. This is step one in the process referred to above.

Best Regards

From: Wilcox Lisa <>
Subject: Re: [DNA] new world of SNPs in R1b
Date: Fri, 5 Feb 2010 11:53:07 -0800
References: <077C15557F514BC292036855FBFE388B@PC>
In-Reply-To: <077C15557F514BC292036855FBFE388B@PC>

On Feb 5, 2010, at 11:25 AM, Lancaster-Boon wrote:

> ... the new world of SNPs in R1b.

Would someone be willing to summarize this for a layperson? How does
it impact those of us pursuing "recent" genealogy?

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