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Archiver > GENEALOGY-DNA > 2010-03 > 1268621614


From: "Diana Gale Matthiesen" <>
Subject: Re: [DNA] Clades, Definitions, Discoveries, FTDNA
Date: Sun, 14 Mar 2010 22:53:34 -0400
References: <270548.86246.qm@web111316.mail.gq1.yahoo.com>
In-Reply-To: <270548.86246.qm@web111316.mail.gq1.yahoo.com>


Mike,

I apologize if I wasn't more clear because you have gone to a lot of effort to
deal with something that's really very simple, namely, that L21+ is the derived
trait differentiating R-1b1b-2a1a-2f and its subclades *from R-1b1b-2a1a-2,* not
from *all* other clades.

The ancestral traits for R-1b1b-2a1a-2f (viz., P312+, P310+, M269+, P297+, P25+,
M343+, M173+, M207+...etc.) can only place it in the next higher clade (R-P312),
along with its sister clades, R-1b1b-2a1a-2a, R-1b1b-2a1a-2b, etc.

Diana

> -----Original Message-----
> From: On Behalf Of Michael Maddi
> Sent: Sunday, March 14, 2010 8:59 PM
> To: Genealogy-DNA List
> Subject: Re: [DNA] Clades, Definitions, Discoveries, FTDNA
>
> Diana Gale Matthiesen wrote:
>
> 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 example...
>
> 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.
>
> My reply:
>
> I certainly don't have the expertise in cladistics that you
> have, but I just can not let pass what I have quoted from you above.
>
> You claim that the only defining (pardon me, Ken)
> characteristic of the clade we call R-L21 is the SNP that has
> been named L21. You write that "It is not defined by it's
> symplesiomorphies (viz., P312+, P310+, M269+, P297+, P25+,
> M343+, M173+, M207+...etc.) which are shared by other clades."
>
> So if a SNP shows up at the same location as L21 on the y
> chromosome and has the same change in nucleotide base as L21,
> but occurs in a man SNP-tested as in haplogroup J1, does that
> make that man a member of the R-L21 clade? By your definition
> above, it would seem to, because we should not inquire into
> whether the man is positive for the SNPs known to be upstream
> of L21 in R-L21 men, namely "P312+, P310+, M269+, P297+,
> P25+, M343+, M173+, M207+...etc.," to quote you again.
>
> Ken had it right in another thread here (see
> http://tinyurl.com/yglsyyf ) today where he answered a
> question about the benefits of a full genome sequence for
> establishing a tree for the y chromosome. To quote him: "Full
> sequencing of just the y chromosome for enough males can essentially
> map out the entire human y tree, and each of us males can
> have a branch
> routing worked out back to genetic Adam 70,000 years ago or
> so. It will not be as complicated as you might imagine. While
> it may be about 2300
> generations long, what will personalize the branch routing
> will be defined
> by only about 50 or less forks in the route taken. I remember
> memorizing
> the 50 state capitols as a kid; my grandsons could
> conceivably memorize and recite a little story about their 50
> steps back to genetic Adam, i.e. the MRCA of all mankind's males."
>
> The point I'm making here is that Ken's understanding of the
> tree and its branches and twigs means that a clade or
> subclade or whatever you want to call it actually represents
> a population descended from a common ancestor. You seem to
> regard each SNP as a separate event that conveniently allows
> us to class categories of men together without regard for
> their relationships to men on other twigs and branches, who
> are the yDNA equivalent of grandfathers, fathers, uncles,
> brothers and cousins. In other words, their ancestry and
> relationship to other men can be mapped out by SNP testing,
> as the quote from Ken above describes.
>
> If I've misinterpreted what I've quoted from you about R-L21
> above and you actually understand R-21 men as related somehow
> to men in other subclades who are "P312+, P310+, M269+,
> P297+, P25+, M343+, M173+, M207+...etc," please clarify for me.
>
> Mike Maddi
>
>


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