Archiver > GENEALOGY-DNA > 2010-03 > 1268522304

From: "Diana Gale Matthiesen" <>
Subject: Re: [DNA] Clades, Definitions, Discoveries, FTDNA
Date: Sat, 13 Mar 2010 18:18:24 -0500
References: <><><><00e201cac145$82fec7c0$5e82af48@Ken1><><017901cac159$4e6c7020$5e82af48@Ken1><086F1093A566477B815995B401BB889C@HP><><><000601cac1f5$b5338040$5e82af48@Ken1><294168F50E07487A812B78EBD02BCBF4@HP><><BCC91D9EA86E43FCBF0F1AEAFB5CD7A7@HP><011b01cac212$8b6e9340$5e82af48@Ken1><65609D4617B84F15B9653A789115A218@HP><013801cac216$a3a77450$5e82af48@Ken1><D7C366EF2B1D47A89D465B482BD0B343@HP><><0AAEE7A9F5B949C68C94CFFDA0716573@HP><><24C7C69E735341B1B6B5ABAE63842C42@HP><>
In-Reply-To: <>

> -----Original Message-----
> From: On Behalf Of Vincent Vizachero
> Sent: Saturday, March 13, 2010 5:12 PM
> To:
> Subject: Re: [DNA] Clades, Definitions, Discoveries, FTDNA
> Again, good grief.

Double good grief.

> You have, repeatedly, invoked the polarity of markers as a defining
> characteristic of clades. For example, you wrote: "Y-DNA
> haplogroups (clades) are not defined by their demographic
> properties, they are defined by the polarity of their SNP mutations."

My statement that "Y-DNA haplogroups (clades) are not defined by their
demographic properties" is true, regardless of whether the second half of the
statement is true, though it is.

> As we both now (it seems) agree, this statement is not true. Clades
> are not defined by the "polarity of their SNP mutations" but
> rather by the shared ancestry of their members.

No, we do not agree. The clades on the Y-DNA haplotree are defined by the
polarity of their SNP mutations, which is a succinct definition. A broader
definition would be that Y-DNA haplogroup clades are defined by their placement
on the Y-DNA cladogram as determined by a cladistic analysis of the polarity of
their SNP mutations.

Clades are not defined by their plesiomorphies (ancestral traits), but by their
synapomorphies (shared derived traits), which in the case of the Y-DNA haplotree
is their shared derived SNPs. Which term applies depends on your perspective
(location) in the tree, but each new clade is defined by the appearance of a new
derived SNP -- it's apomorphy -- not its symplesiomorphies. Here's an

L21+ defines a clade we call R-L21 or, as currently labeled in the ISOGG
hierarchy, R-1b1b-2a1a-2f. The clade is defined by L21+, which is a derived
trait, an apomorphy. It is not defined by it's symplesiomorphies (viz., P312+,
P310+, M269+, P297+, P25+, M343+, M173+, M207+...etc.) which are shared by other
clades. If you create clades based on their symplesiomorphies, such as lumping
R-L21 together with R-SRY2627, which would be a valid clade based on that
criterion, you end up with clades that are not monophyletic.

To put this in lay language, the ancestry is deduced from the cladogram, not the
other way around. You have the ancestry defining the clades and that is
backwards. The evolutionary tree evolved from the roots to the leaves, but the
haplotree was deduced from the leaves to the roots -- because the only real data
we have is the leaves. This is absolutely basic cladistics (not to mention

> Subsequently you paraphrased Ken as saying that ""tags" (genetic
> mutations) do not make the clades. . . " and proceeded to accuse him
> of being wrong.

He is.

> If I've made the point that HE wasn't wrong, then I have
> accomplished something.

You have only accomplished digging yourself in deeper. What's that saying about
being in a hole? And now I'm late for dinner...

> VV
> On Mar 13, 2010, at 4:32 PM, Diana Gale Matthiesen wrote:
> > If you're going to give my messages such a cursory read,
> > please stop responding because this last interchange
> > accomplishes absolutely nothing.

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