GENBRIT-L Archives

Archiver > GENBRIT > 2006-01 > 1137420530


From: "Rob" <>
Subject: Re: Most recent common ancestors
Date: Mon, 16 Jan 2006 14:08:50 -0000
References: <1137338990.456458.231910@f14g2000cwb.googlegroups.com> <mo4ms15t5bs77ev0ds8bhs690882gdmb15@4ax.com> <dqf5c5$rl4$1@newsg1.svr.pol.co.uk> <dqff7p$afe$1@eeyore.INS.cwru.edu>


"Todd A. Farmerie" <> wrote in message
news:dqff7p$afe$1@eeyore.INS.cwru.edu...
> They do not show that he was a descendant, they show that he belonged to
> the same maternal lineage.
Actually no it shows they had the same paternal lineage because they didn't
carry out MtA sequencing as far as I know. After all the Y chromosome is
the only one that doesn't become altered birth after birth.

> Anyhow this misses the point. As has already been pointed out, virtually
> all North American 'natives' probably also descend from post-Columbus
> Euros, even if only through a single
> great-great-great-great-great-great-(etc)-grandfather. The fact that they
> are members of tribes that predate Columbus does not negate this. In other
> words, there is nothing to stop the schoolteacher in question from being
> descended from BOTH the Cheddar man AND Ghengis Khan.

Thats very argumentative with little or no evidenc eto back it up. It is
based on a weak set of guidlines.
>
> That being said, I also find the model flawed, but because it ignores
> inbreeding and isolated populations. Inbreeding was extensive, not so
> much on the level of first-cousin marriage, although that did happen, but
> in terms of most rural villages, where after a couple of hundred years
> with minimal migration they were all descended from the same people and no
> marriage within the community expanded the genetic heritage in the
> slightest. It also means that once a fresh lineage is introduced, it too
> becomes saturating within a couple hundred years. The key, then, is
> isolation, and there are populations so isolated that it is unlikely they
> have acquired European ancestry, and certainly all of Europe has not
> acquired descent from them. In short, such statistical approaches require
> dramatic over-simplification to produce results, but these same
> simplifications that make the analysis possible likewise doom the results
> to represent nothing more than a statistical exercise.
>
> taf

Couldn't agree more. Yet again the simplification of how the data is read

Rob


This thread: