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Archiver > DNA-R1B1C7 > 2009-12 > 1260518960


From: "Gregory Brown" <>
Subject: [R-M222] Coyne and Golden project families
Date: Fri, 11 Dec 2009 08:09:20 -0000
In-Reply-To: <mailman.25.1260432006.9391.dna-r1b1c7@rootsweb.com>


Sandy,

Now you're just being nasty. I don't believe that referring to good-faith comments relating to
probability, genetics and population dynamics as "plain rubbish" is very constructive or a good
demonstration of your level of self-proclaimed expertise...well, perhaps the latter, but certainly
not the former.

And "goes beyond plain rubbish" is just plain rude.

If you wish to hang your authoritative hat on circular reasoning by using a living population sample
to erect a modal haplotype, and then use that same sample-derived modal haplotype to deny the
significance of a 67-67 match, then you may as well stop wasting your time assuming DNA testing can
determine relatedness at all. 60 generations without a mutation? Hardly likely. Show me a group of
people who can prove their common ancestor back 6 generations who don't have a GD of 1, 2 or even 3
at the 67 marker level...or even the 37 marker level, and you might get my attention.

You don't know the haplotype of the original male, yet you ASSUME that the modal you have calculated
from a relatively tiny sample of R-M222 is the original male's haplotype, and you proclaim (without
evidence) that those who match this small-sample derived "modal" 67-67 have preserved or reverted to
this hypothetical haplotype and defied the laws of probability across potentially hundreds of lines
and 60 generations?
Even if you do accept this (which is not at all parsimonious), it is all dependent upon your
hypothetical modal being correct (exactly correct). If it isn't, and the actual ancestral haplotype
is that of one of your "significant" multi GD off-modal matches, then it is the latter who are no
longer of determinable relatedness, and the former who are now regarded as significantly related.
And remember, as the sample size and diversity increase, the calculated modal changes!

Occam's razor is sure going to get dull on that one.

Your "logic" regarding how we cannot draw conclusions from *lack* of evidence should be equally
applied to your analysis of evidence based upon unproven assumptions. There is no evidence in
unproven assumptions or estimates.

> I give you my authoritative opinion that you are way off
> base. If you want a
> second opinion, contact me tomorrow and I'll give you a
> second opinion with
> the greatest of pleasure.
>
>
> Sandy

Thanks, Sandy, I'll pass. You don't owe me a second opinion, regardless of how much pleasure it
would give you. But, as a very active member of this list, you DO owe the members a bit more
substantial explanation for what you are espousing. Maybe a reference or two to a papers which can
explain why a 67-67 modal match between two people is insignificant in determining relatedness?
Now, THAT would be appreciated.

Greg






> Date: Wed, 9 Dec 2009 20:46:08 -0000
> From: "Sandy Paterson" <>
> Subject: Re: [R-M222] Coyne and Golden project families
> To: <>
> Message-ID: <000301ca7910$a343fd20$e9cbf760$@com>
> Content-Type: text/plain;charset="us-ascii"
>
> No, we cannot test the DNA of the original male.
>
> But we can make a reasoned guess at his haplotype. We can
> observe the modal
> of the M222+ population. In the knowledge that M222+ is very
> young (some 60
> generations), we can work out (no college education required)
> that it won't
> be too far from the observed modal. We can (and have) done
> simulations that
> test the frequency with which a given set of marker values produce an
> observed modal different to the starting haplotypes due to
> mutation over 60
> generations.
>
> @
> More specifically, there is a flaw in logic. In order for
> the exact 67-67
> matches with the modal
> haplotype to be meaningless (or less meaningful), you would
> have to assume
> or propose that the markers
> for the modal haplotype have not mutated at all since the
> original male
> (almost infinitely small
> probablility) or that they have experienced a long series of
> mutations and
> reverse mutations that
> coincidentally reverted to the original (modal) haplotype
> (also infinitely
> improbable). In order to
> argue that the off-modal matches are more significant indicaters of
> relatedness (to one another) than the
> "on-modal" matches are (to one another), you would have to
> argue that the
> laws genetics and probability
> somehow apply differently to the modal than to any other
> haplotype. This
> isn't tenable.
> @
>
>
> Plain rubbish.
>
> You simply have to observe that either way (meaning either no
> mutations or
> mutations that have reversed), there is no evidence that any
> mutations have
> been passed down from a common ancestor.
>
> @
> In order to argue that the off-modal matches are more
> significant indicaters
> of relatedness (to one another) than the
> "on-modal" matches are (to one another), you would have to
> argue that the
> laws genetics and probability
> somehow apply differently to the modal than to any other
> haplotype. This
> isn't tenable
> @
>
> This goes beyond plain rubbish.
>
> If there is no evidence of mutations having been passed down,
> there is no
> evidence. That's that. Laws of probability? Laws of Genetics?
> No. Just plain
> logic. The absence of evidence is just that. An absence of evidence.
>
> If, on the other hand there is evidence that mutations MAY
> have been passed
> down (the evidence being off-modal matches), then there
> exists a non-zero
> probability that the mutations may have occurred in a common ancestor.
>
> @
> I have searched for "expert opinion" about this discussion with little
> success. It seems most references
> are too basic to address this, or too advanced to bother
> discussing it. I
> would certainly hope there is
> someone monitoring this thread who could fill that information void
> authoritatively. I'd sure like to
> know if I'm completely off base with my understanding of things.
> @
>
> I give you my authoritative opinion that you are way off
> base. If you want a
> second opinion, contact me tomorrow and I'll give you a
> second opinion with
> the greatest of pleasure.
>
>
> Sandy
>



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