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Archiver > DNA-R1B1C7 > 2012-03 > 1332929554


From: Malcolm McClure <>
Subject: Re: [R-M222] Geographical distribution of M222+
Date: Wed, 28 Mar 2012 11:12:34 +0100
References: <mailman.33.1332831605.6995.dna-r1b1c7@rootsweb.com><4F71B0A6.6070005@earthlink.net><89EF7258-4726-4158-A2DF-C21E442D1E70@me.com><000101cd0cb2$95151030$bf3f3090$@com>
In-Reply-To: <000101cd0cb2$95151030$bf3f3090$@com>


Sandy

We can only have confidence in statistical methods based on samples if they can be calibrated and verified. So far as I know, no group has yet established a verified line of descent from a known MRCA extending back 2000 years. I am unaware also of peer reviewed studies in any field where variance ratios of (samples including estimates) from different populations have divulged verifiable results in the time domain.

Mike's statistical method assumes that all point mutations are equally random, unidirectional and unaffected by variation with time of environmental mutagens such as solar radiation and nicotine.
Each of those assumptions seems at best to be questionable.

Malcolm.

On 28 Mar 2012, at 08:15, Sandy Paterson <> wrote:

> Malcolm
>
> I don't believe what Mike did in dividing the sum of observed variances of
> M222+ by those of P312 is an abuse at all. Of the 111 markers in the largest
> FTDNA test, only about 35 of the mutation rates are (reasonably)
> well-researched the remaining 76 have to be estimated in order to do
> estimated TMRCA calculations. Of the 67-marker panel, about 26 are fairly
> well-researched, with very little known about the remaining 41.
>
> I have chosen for the most part to quote sum of variances rather than
> ETMRCA, but Mike chose to quote ratios to P312. So when he quotes a figure
> of 0.63 for M222+, that means by his estimate, M222+ is about 63% as old as
> P312. I can't see anything wrong with that at all, although I don't believe
> it is accurate to use fewer than around 50 markers in the summation. In any
> event, ETMRCAs are not normally distributed, they are skewed, with a long
> tail at the high values and a shorter tail at the lower values.
>
> Sandy
>
>
>
>
> -----Original Message-----
> From:
> [mailto:] On Behalf Of Malcolm McClure
> Sent: 27 March 2012 14:56
> To: ;
> Subject: Re: [R-M222] Geographical distribution of M222+
>
> Susan
>
> I welcome your clear statement about the aims and objectives of M222
> correspondence.
> It was beginning to get diverted by speculations about the dim and distant
> past rather than being confined to evidence concerning the relevant past two
> millennia. Until we can establish a clearer identity for our tribal
> antecedents, their strifes and allegiances over the generations, their
> migrations and bottlenecks, we are unlikely to establish individual family
> and surname antecedents with confidence.
> The recent correspondence about Variance ratios seems to me to be a misuse
> of statistical tools that were devised to reflect the shape of Normal
> Distributions based on a single measurable variable. Lumping variables makes
> for nonsense statistics.— Just my 2¢ worth.
>
> Malcolm.
>
>
>
> R1b1c7 Research and Links:
>
> http://clanmaclochlainn.com/R1b1c7/
> -------------------------------
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