Archiver > GENEALOGY-DNA > 2010-03 > 1268943402

From: "Ken Nordtvedt" <>
Subject: Re: [DNA] Expected NPE's Over 800-1000 Years
Date: Thu, 18 Mar 2010 14:16:42 -0600
References: <><>

You mean (1-p) raised to the nth power? Some may read your "(1-p)n" as n
times (1-p)

----- Original Message -----
From: "Nancy Kiser" <>

> Hi, Lindsey,
> The probability that a living male will carry the Y-signature of his
> surname’s progenitor from n generations ago is (1-p)n, where p is the
> fractional probability of a non-paternal event at each generation. So
> first you have to decide what rate of NPEs per generation you think is
> reasonable and then you have to decide how many years constitute a
> generation. I have read where some experts think 2% to 3% per generation
> is a reasonable estimate of NPEs and many experts use 25 to 30 years to
> calculate a generation.
> Nancy Kiser

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