GENEALOGY-DNA-L Archives

Archiver > GENEALOGY-DNA > 2007-09 > 1188641789


From: <>
Subject: Re: [DNA] Haplogroup I in Europe
Date: Sat, 1 Sep 2007 06:16:29 -0400
References: <ceb.19833613.3409ec4e@aol.com><004d01c7ec20$044e7df0$6400a8c0@Ken1><00e301c7ec41$45b70480$6401a8c0@Richard>
In-Reply-To: <00e301c7ec41$45b70480$6401a8c0@Richard>


"Genetic drift" is an entirely appropriate term, so there's no need to change it
and certainly no reason to discard it because it describes a phenomenon seen in
population genetics. In large populations, the effect is virtually nil, but as
you surmise, the effect is highly significant in small populations (e.g.,
bottlenecks and founder effects).

Your family is part of a larger population with which it is interbreeding, so
the chance breeding in your family will have no perceptible effect on the
genetic diversity of the population. In other words, all the alleles you carry
are carried by others in the population, so your brothers dropping out of the
gene pool is not an overall loss to the population. Even if you and your
brothers are the last living carriers of a rare allele, your survival and
reproduction will not stave off the inevitable outcome: that your allele will
disappear via genetic drift.

If you lived on a South Sea island with a population of a few hundred, it might
matter.

Diana

> -----Original Message-----
> From: On Behalf Of R. Stevens
> Sent: Friday, August 31, 2007 10:39 PM
> To:
> Subject: Re: [DNA] Haplogroup I in Europe
>
___________________________________________
>
> That may be true, but it still seems a useful term. Perhaps
> we should call it something else?
>
> I have two brothers. One of them has only one child, a girl. The other one
> has two girls. I have two sons, and my youngest son now has two sons. My
> dad's y-line has already drifted in my direction, since it is highly
> unlikely that either of my brothers will have any more children.
>
> Maybe that's not the best example, since it begins with three men who belong
> to the same haplogroup and probably even have the same haplotype. But in a
> small village something similar could easily occur involving different
> y-haplogroups and have a profound effect on the genetic make-up of the
> village or tribe. The smaller the village or tribe, the bigger and quicker
> the effect.
>
> Rich
>
>
>
>

This thread: