Archiver > GENEALOGY-DNA > 2010-11 > 1289770385

From: "Ken Nordtvedt" <>
Subject: Re: [DNA] Explaining Haplogroup Success
Date: Sun, 14 Nov 2010 14:33:05 -0700
References: <00ec01cb8433$d1e05690$c2482dae@Ken1> <>

----- Original Message -----
From: "James Heald" <>
But if a single
> lineage gets injected just before a population undergoes a burst of very
> rapid growth and range expansion, the chances are much higher that it
> will survive.

My original message was not so much to reveal the very high extinction rate
of lines in typical populations --- that's old news --- but it was meant to
stress that two individual lines in most any population will end up most
typically with very different final populations --- and based just on the
luck of reproduction. I did not want to focus on the zero growth aspect of
the first example; that was just a bench mark. I'm trying to throw a bit of
cold water on any notion that y haplogroups that win the demographic lottery
in any region necessarily need any profound reason for doing so? Maybe
there are some contributing reasons, but perhaps not.

So here's another example with 10 percent per generation growth rate.
Again, we go 30 generations, and because of the lower extinction
probabilities of lines I just do 100 trials instead of the 300 I did in
first example.

76 trials went extinct before 30 generations.

Here are the descending populations of a line for the 24 trials with
survivors after 30 generations:

86, 183, 8, 111, 70, 9, 136, 209, 120, 43, 147, 16, 4, 142, 234, 69, 114,
200, 16, 221, 213, 28, 27, 27

Again, there are wild flucuations in the final surviving populations,
although ratio-wise maybe not so large?


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