Archiver > GENEALOGY-DNA > 2010-12 > 1292178379

From: Vincent Vizachero <>
Subject: Re: [DNA] NW European R1b from Iberia?
Date: Sun, 12 Dec 2010 13:26:19 -0500
References: <><><><00ab01cb9a25$c733a870$c2482dae@Ken1>
In-Reply-To: <00ab01cb9a25$c733a870$c2482dae@Ken1>

On Dec 12, 2010, at 12:55 PM, Ken Nordtvedt wrote:

> [[ You are being excessively pessimistic and blowing out of proportion
> differences of so called "true clades" from paragroups. P312* is as
> much a
> single group as is L21, etc.

I'm not sure how you'd define "single group", but it is not "as much"
a clade as R-L21 is. R-P312* is, by definition, a remainder set.

It may be that you are thinking that all R-P312* has a MRCA more
recent than the MRCA of R-P312, and that does remain a possibility.
But it is by no means assured, and as Mike observed, the structure of
R-P312* could and quite likely does vary depending on geography. So
comparing the variance of R-P312* across Europe does not achieve the
same function as comparing the variance of R-P312 across Europe.

> As long as you draw trees to visualize what assorted branch lines
> you are
> conceivably summing over (and therefore averaging) in each
> application, the
> meaning (and any limitations thereof) of intraclade variances and
> interclade
> variances involving paragroups can be stated.

That's true only if the trees you can draw are accurate. Based on the
small number of STRs available to us today, such trees are not at all
accurate within R1b1b2 - and especially not within R-L11 - given the
"bushy" nature of this portion of the tree. I maintain that STR-
based phylogenies CAN be useful and accurate, but they are not always
thus. R-P312 is one place where they are not.


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