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Archiver > GENEALOGY-DNA > 2005-12 > 1135160272


From: "John McEwan" <>
Subject: RE: [DNA] Dal Riata Modal Haplogroup
Date: Wed, 21 Dec 2005 23:17:52 +1300
In-Reply-To: <BKEPIIDHHKEPCMDIEBKBIEDCCNAA.andrew.en.inge@skynet.be>


Dear Andrew

A slow reply


>John: The R1bSTR47Scots cluster, obviously came from Europe at some
stage
>after the LGM, when and by what route is the question. [...] At its
>simplest it "evolved" in Britain.
>
>So when you say it came from Europe are you suggesting that "it" was
not >yet the Scots cluster at the time?

I do not know. There are two possibilities. It developed in a location
(say southern England) and then expanded and spread for some reason like
early adoption of agriculture by carriers of the haplotype causing an
relative increase in their population relative to other haplotypes. The
second is it developed elsewhere and was imported and
expanded/displaced/replaced existing inhabitents. How can we test this?
Well having a decent sample of haplotypes across all geographic regions
(esp geographic regions of Ireland France, Belguim ....) and then
testing the diversity of the haplotypes in this cluster from each region
would help. If diversity was greatest in a region then it probably
developed there and so on. Now if the group could be defined by a SNP
this would ease classification of individuals as well.

>I hope I mentioned somewhere that I am convinced about
>the significance of *the cluster*, and you have played a role in
convincing
>me. But for the people looking at this from a genealogical or clan
history
>point of view there is a another question: could there have been
scattered
>convergence amongst *individual* families (both in the Scots homeland
and
>outside)? In other words, could some of the particular seeming Scots
>families descend from a different part of the R1b family tree? To me
that
>seems possible.

It is possible the question is whether it is probable. While we can do
simulations to estimate the likelihood, based on the responses from the
list there are only two ways out of the dilemma for the sceptics. The
first involves identifying a SNP that broadly matches the cluster. The
second is that individuals test so many STRs that even sceptics accept
that convergence is unlikely between the groups. How many STRs you ask?
My guess is between 70 and 100 STRs are required to ensure that >95
percent of R1bSTR47Scots individuals are classified correctly within R1b

>So do you think there is yet enough evidence to say that Colla Uais or
any
>similar figure such as Fergus mac Erc was of the Scots lineage? This is
not
>a saracastic question by the way. Just looking around the web as an
>outsider it does not seem that there is even an agreed upon family tree
for >Colla Uais?

I have not examined the evidence in exhaustive detail, others have.
Therefore I cannot make a statement either way. What I have concerns
about is the implied inference that if anybody has a haplotype close to
the "Colla Uais" modal (which is nearly identical to the R1bSTR47Scots
modal) and inhabit that cluster of haplotypes then they are descended
from Colla Uais. The pattern of distribution, surnames involved,
frequency and age and diversity of the haplotype make this rather
unlikely.

In fact if I was being really provocative I could suggest the reason
Colla Uais modal is close to the R1bSTR47Scots modal, is because if you
take a bunch of people from a locality with common surnames and common
haplogroup/subclade they probably reflect a very deep ancestral pattern
in the region. Therefore perhaps not surprisingly the "desired" ancestor
of the group appears to have the modal haplotype for that
region/cluster. The ancestor may have even had a similar haplotype, but
the modal of a geographically much more widely dispersed group???

This situation is less likely to occur when the haplotype is relatively
rare and the introduction rather limited in time e.g. Somerled.

Rephrased my question is how do you distinguish individuals with a
similar haplotype and the same surname(s) but not descended from Colla,
from those that are when the haplotype is already frequent in the
ancestral population? You can't and as a consequence the calculated
modal for the ancestor will tend to drift to the modal of the wider
cluster.

Cheers

John McEwan


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