GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2010-08 > 1281594079
From: "Diana Gale Matthiesen" <>
Subject: Re: [DNA] SRY10831 at the root ?
Date: Thu, 12 Aug 2010 02:21:19 -0400
References: <14652681.68880.1281112386993.JavaMail.www@wwinf1j16><007301cb35b9$87f2cf90$48692dae@Ken1> <email@example.com><005e01cb37c4$34d2a990$48692dae@Ken1> <firstname.lastname@example.org><015001cb3811$81e5c670$48692dae@Ken1>
> -----Original Message-----
> From: [mailto:genealogy-dna-
> ] On Behalf Of Ken Nordtvedt
> Sent: Monday, August 09, 2010 6:24 PM
> Subject: Re: [DNA] SRY10831 at the root ?
> ----- Original Message -----
> From: "Diana Gale Matthiesen" <>
> > If there are 2500 SNPs separating you from genetic Adam, then there are
> > 2500 nodes/branches on the cladogram. > Diana
> [[ It would help if you slowed down and thought before diving into this
> stuff. The vast majority of those 2500 generations and comparable number of
> generations on the line between genetic Adam and myself were males who had
> just a single male child in the full y tree leading to all males of today.
> The tree of males is determined by demographics, not mutations.
If you said "generations" and I read "SNP mutations," then yes, I misread you,
so mea culpa. Senior moment.
But you are misusing the term, "demographics." The word you want is
"genealogy." If you are saying that your genealogical family tree is not the
same as the SNP haplotree, then of course, I agree with you. Your genealogy
should be congruent with the Y-DNA haplotree, but the SNP tree and your personal
family tree are two entirely different things. Your paper genealogy is, in
fact, not a cladogram, at all. That doesn't make it untrue, it just means
producing it is not science, it's historical documentation.
> A father in the tree needs to have two sons in the tree at least for him to
> be the upstream edge of a node. That has been a very uncommon situation for
> most of the history of the y tree from genetic Adam. Even today it is
> probably the norm. My grandfather had one son who had one son who had one
> son. There's four generations right there without a node, but probably more
> than one snp has happened over that branch segment. ]]
If we are talking about the Y-DNA haplotree, then a single son begins the clade,
even if he's an only child -- other male kin of the father will perpetuate the
ancestral condition. If you are talking about your family genealogy and you
want to call the branches "nodes," then we would have to be looking, not merely
at SNP mutations, but at the entire genome. In that sense, every child born
would be a node on the genome-tree.
P.S. Yes, identical twins could be considered one clade at conception, but they
start changing from that moment on.