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From: "Ken Nordtvedt" <>
Subject: Re: [DNA] Germans who carry J and G (was PLOS Genetics)
Date: Mon, 10 Dec 2007 11:41:12 -0700
References: <mailman.15444.1196880192.17915.genealogy-dna@rootsweb.com><a06240824c37f492d762f@192.168.1.47><REME20071207144722@alum.mit.edu><246baaff0712100818l6eb83adblb5a8b3049f4fc9a5@mail.gmail.com><REME20071210131241@alum.mit.edu>


----- Original Message -----
From: "John Chandler" <>
To: <>
Sent: Monday, December 10, 2007 11:12 AM
Subject: Re: [DNA] Germans who carry J and G (was PLOS Genetics)


> Paul wrote:
>> Actually Germans - and other northern Europeans - cluster separately
>> from south-eastern Europeans which shows that the amount of mixing was
>> likely to be low.
>
> To "cluster separately" in this case merely means to have different
> statistics overall. All it shows -- and all it can possibly show --
> is that mixing is not yet *complete*. To assess the degree of mixing
> solely from the DNA, we would need to take a sampling of an unadmixed
> population for comparison, but that's impossible because we don't have
> access to DNA from the distant past.
>
> John Chandler

That's an interesting prejudgment or generalization --- "that mixing is not
yet complete". While it is perhaps reasonable to look at present world
trends of transportation, immigrations, etc., and say mixing is on a roll
but not yet complete, one can look at the last 60,000 years of modern man
during its dispersals and isolations into a by and large unpopulated world
and conclude that during this era genetic differences between local
populations increased. And then the eras of agriculture,
industrialization, and health improvements initially had the simple effect
of drastically multiplying the genetically different local populations
before anything else. So until someone wants to try to quantify the
increased mixing that very recent human history may now be producing and
compare it with the accumulated "differentiations" that were produced over
50,000 years, I'd guess that mankind is still more genetically
differentiated today than it was in the time of genetic Adam and Eve.

Ken


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