DNA-R1B1C7-L Archives

Archiver > DNA-R1B1C7 > 2009-04 > 1240502110


From: "Sandy Paterson" <>
Subject: Re: [R-M222] Byrne TMRCA Estimates
Date: Thu, 23 Apr 2009 16:55:10 +0100
References: <e0d2d2870904230758i31eeedfam72009bff30f30cfd@mail.gmail.com>
In-Reply-To: <e0d2d2870904230758i31eeedfam72009bff30f30cfd@mail.gmail.com>


Hi David

The method set out in my posting at 15:43 on 16 Apr 2009 was never intended
to be the answer to all questions. It is merely a starting point to
indentify family groupings that seem to be close to each other. For example,
the 'closeness to Ewings' table :


Cowan6.272
McGonagill6.187
McLaughlin4.299
Dunbar3.156
Daugherty2.970
McCord2.419
Burns1.914

suggests that Cowan may be close. A closer look identified DYS449 and CDYa
as the two main causes of this, with the other markers almost irrelevant.
The next step was to look more closely at how significant the two markers
are, in particular examining the frequency with which both are matched :

DYS449=31 AND CDYa=37 Both present

Ewing14/22.6364
Cowan15/25.6000
Other M222+15/380.0395
Total44/427.1030

In terms of significance we are now way off the Richer scale,
notwithstanding the general disdain for the relevance of fast-moving markers
- the combination is very rare indeed, yet both Ewing and Cowan have high
observed frequencies.

The next step is to attempt to estimate the TMRCA for Ewing/Cowan. Since all
of M222+ are thought to have had a common ancestor in the past 1500 years or
so, that must be true of Ewing/Cowan too. So now we postulate a haplotype
from which both must have sprung. The obvious one would be the M222+ modal
but with DYS449=31 and CDYa=37.

Now the fun starts.

I've decided to approach this by adapting the method explained in my
postings on 11 Jan, 14 Jan and 15 Jan under the heading Genetic
Distance/Diversity. Much head scratching at the moment but I may have some
estimates by early next week.


Sandy


















-----Original Message-----
From:
[mailto:] On Behalf Of David Ewing
Sent: 23 April 2009 15:59
To:
Subject: Re: [R-M222] Byrne TMRCA Estimates

I, too, am not certain that the ancestral value among Ewings was not DYS391
= 10, and for me this would justify considering two alternative Ewing
modals, one with DYS391 = 10 and the other with DYS391 = 11. Still, I think
that comparing percentages of off-modal matches between individual
haplotypes is an exercise in futility, because as John says, it will make
too much of parallel mutations.

Have a look at this comparison table of modals for the various Ewing Groups,
including those NOT in M222+:
http://dl.getdropbox.com/u/431003/ModalComparisonTable.pdf
Notice that Group 4a matches the Ewing modal at DYS19 = 15. I have had
project participants flash on that and think that this must suggest a
relationship between the Ewings in Groups 1 & 2 with those in 4a, but Groups
1 & 2 (and 3, as well) are all in R:M222, but those in 4a are not. This is
just a parallel mutation and it is just a bother.
R1b1c7 Research and Links:

http://clanmaclochlainn.com/R1b1c7/
-------------------------------
To unsubscribe from the list, please send an email to
with the word 'unsubscribe' without the
quotes in the subject and the body of the message

This thread: