Archiver > GENEALOGY-DNA > 2010-03 > 1268945469

From: "Ken Nordtvedt" <>
Subject: Re: [DNA] Age of R1b Cohane
Date: Thu, 18 Mar 2010 14:51:09 -0600
References: <><>

----- Original Message -----
From: "SVass" <>

And of course, I should have used the qualifying modifier "minimum" so my
sentence should have read:
> Minimum Coalescence Age of A&B is 2650 years.
> Anyway, as the ht-35 groups are early clusters, they should be relatively
> near the origin of M269 in both space and time.
> sam

That's a problem with mixing interclade node ages with the separate clade
TMRCAs or coalescence ages.

There is no a-priori reason the separate clade TMRCAs and coalescence ages
should hug the interclade node ages. Quite often the tree structure
connecting different clades consists of just two single branch lines going
back from the separate clade MRCAs to the interclade node.

Case in point, although admittedly chosen to be particularly dramatic.

I1 TMRCA is about 4500 years. I2a3-Western TMRCA is about 2500 years.
Interclade node age between them is over 20,000 years ago.

On the other hand for the relatively young clades, I think we found the P312
TMRCA hugging close to the interclade age between P312 and S21 at about 4000
years. But that's because we are now working in the middle of the bushy
part of the tree.

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