I don't think its that difficult to see why only one Y-chromosome
lineage would eventually be left. Consider the simplified case of
100,000 men and 100,000 women, and let each of them have two children.
That next generation, only 75000 of the 100000 original Y-chromosome
lineages will be represented. Each generation, you lose another quarter
of the contemporary lineages, until after some N generations, 100000 *
(3/4)^N =~1 . If you assume a higher birth rate, and let the rate vary
stochastically across the population, you will still have lineages
dropping out, just at a much slower rate. On a smaller scale, we have
the case of last names on Pitcairn island, where the survivors of the
Bounty settled. Out of several dozen men, only a handful of last names
are now represented. Similarly in China, where family names have been
relatively stable for a couple millenia, 200 family names account for
96% of the population.
Lucien.
Glenn Morton wrote:
>
> >-----Original Message-----
> >From: Walter Hicks [mailto:wallyshoes@mindspring.com]
> >Sent: Thursday, April 25, 2002 2:34 AM
>
> >I understand that, but it is exactly what I meant, Glenn. I should have
> >more clearly said the direct male descendants (Y-chromosome only). I
> >have heard the argument that sooner or later all but one MUST die out. I
> >can buy it only if there is some reason why that one is very much better
> >than all the others. The argument that 99,999 out of 100,000 must
> >automatically die out (the male chain only) and at the same time say
> >that the 1 remaining produces a lineage of 1,000,000,00 men certainly
> >has to look a bit fishy. I know zip about genetic details but I usually
> >am fair at logic, math and probabilities.
> >
> >One cannot argue with the data, so it must have happened. Why it
> >happened, seems to require more that a simple example of how one
> >randomly selected line can die out. I can generate examples where each
> >line should increase without limit, unless some competition exists with
> >limited resources ---- then it is easy.
>
> I have seen studies where computer programs were written which mimicked
> stochastically exactly the process of the mtDNA or Y chromosome. Beleive it
> or not the number of survivor lineages decreases with time until there is
> one, if the program is run long enough. one example can be seen in John H.
> Relethford, Genetics and the SEarch for Modern Human Origins, (New York:
> Wiley, 2001)p. 171-173
>
> glenn
>
> see http://www.glenn.morton.btinternet.co.uk/dmd.htm
> for lots of creation/evolution information
> anthropology/geology/paleontology/theology\
> personal stories of struggle
> >===================================
-- Lucien S Carroll ucarrl01@umail.ucsb.edu "All mankind is stupid, devoid of knowledge." -Jeremiah 51:17a
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