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Archiver > DNA-R1B1C7 > 2009-04 > 1240387540


From: John Mclaughlin <>
Subject: Re: [R-M222] Byrne TMRCA Estimates
Date: Wed, 22 Apr 2009 03:05:40 -0500
References: <d19.3d757d9f.371fe16f@aol.com><000001c9c314$34d8b770$9e8a2650$@com>
In-Reply-To: <000001c9c314$34d8b770$9e8a2650$@com>


<I'd say 295 is a bit more than a handful. Also, I have 22 Ewings and 25
Cowans. They have 708 off-modal matches. You have 20 Ewings and 35
Cowans so you should find far more than the 708 off-modal matches that I
found.

I am counting all matches at a given marker as one match.

As far as I am concerned this:

391 = 10 (2 Cowan 9 Ewing) 2 X 9 18

is one match. It is one mismatching modal M222 marker.

I went through the spreadsheet and added them up line by line. It was a
pain in the butt and something I guarantee I will not do again but I
wanted to see where you were coming from with your 708 off modal matches.

<I'll go through my workings today and produce a table similar to the
above for comparison. At a quick glance though, I see you've left out
DYS491 from the above table although you do refer to it below, where you say

Where is marker 491 to be found? If you're talking about 449 you're
right. I did somehow leave that out of the table. That's the main one
where the two intersect.

Here's a corrected table:

391 = 10 (2 Cowan 9 Ewing)
449 = 31 (22 Cowan, 20 Ewing)
439 = 11 (2 Cowan 1 Ewing)
19 = 15 (1 Cowan, 21 Ewing)
YCAIIb = 22 (2 Cowan, 2 Ewing)
576 = 17 (1 Cowan, 2 Ewing)
570 = 16 (1 Cowan, 1 Ewing)
570 = 18 (2 Cowann, 1 Ewing)
CDYa = 35 (1 Cowan, 3 Ewing)
CDYa = 36 (2 Cowan, 1 Ewing)
CDYa = 37 (16 Cowan, 14 Ewing)
CDYb = 38 (1 Cowan, 17 Ewing)


<You say that other surnames match DYS449 = 31. Sure. Those matches are
included in my figures.

You said you were just comparing Cowans and Ewings.

<The point is that Cowans have far more such matches
with Ewings than the other family groupings. I don't think you can
dismiss that as not being of zero significance.

I don't know if they do or not. I'd have to compare each by hand.
But I don't think this is the point. I think you're looking for a way
to sub divide M222 into sub-clades with this approach and I don't think
it will work. Many of these off modal matches are probably just
parallel mutations and don't mean anything. Especially when one group
only has 2 or 3 out of twenty samples.

< Do you therefore exclude the slower moving markers too?

I'm not excluding any markers except possibly CDYab. But I put that in
the tables too so nothing is excluded.

<Carry on with this
reasoning and you'll logically end up comparing nothing with nothing and
conclude that all conclusions are inconclusive.

Since this is not my line of reasoning I have no concerns about possible
conclusions. Thanks for the warning though.



John












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