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Archiver > DNA-R1B1C7 > 2008-02 > 1203302416


From: "David Ewing" <>
Subject: Re: [DNA-R1B1C7] Age of R1b1c7
Date: Sun, 17 Feb 2008 19:40:16 -0700


Ken Nordtvedt tells us, "Bottom line: stick to the variance method rather
than GD method."

I'm embarrassed to admit that I'm not entirely sure what to do with this
advice. In statistics, the variance is the square of the standard deviation.
The standard deviation is "the root mean square deviation." To calculate
this for a list of numbers, you compute the average of all the numbers on
the list, subtract this from each of the numbers in turn, square the result,
then add all of the squares up, divide by the number of numbers, and do the
square root of the whole business.

So what in the dickens do we do with a list of haplotypes? I guess we would
have to work marker by marker and each would have its own variance. But how
would we figure the variance among haplotypes as opposed to the variance
among repeat values at a given marker?

David Ewing

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