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Archiver > GENEALOGY-DNA > 2010-03 > 1268623149


From: Angela Cone <>
Subject: Re: [DNA] The tree house definition (was: Clades, Definitions,Discoveries, FTDNA)
Date: Mon, 15 Mar 2010 16:19:09 +1300


Vince is right, Ken is right, Diana is right

(no,.. hell hasn't frozen over,.........yet)

... everyone is right,... and wrong all at the same time... (and no I'm not
being Oxymoronic, nor Ironic)

What all of these clade definition arguments boil down to is not
distinguishing between Taxonomy and Systematics. The terminology that is
being used with Y-DNA has been mushing systematics and taxonomy together as
if they are the same thing (when they are not). This (naturally) causes
confusion, and periodic eruptions of "discussion"

Lets see if I can put it another way:
(and if you read even further I'll treat you to my tree house analogy)...

Clades exist regardless of whether we have found them or not. Biological
variation exists and has happened regardless of whether or not humans have
studied it - ie. if a tree falls in a forest and no one hears it, it still
makes a sound. (that's what Vince and Ken are saying).

Studying biological variation and studying how organisms are related to each
other is called systematics.
Cladistics is just a specific way of studying biological variation and
provides a frame work to base taxonomy on. Vince often uses the term
"Cladistics" when he really means "Phylogenetics".

Giving categories of biological relatedness names/labels is called
Taxonomy. Taxonomic categories are an artificial framework that is "put
around the natural variation that exists". The YCC system of Y-DNA taxonomy
is defined by using binary SNP's using a Cladistic method.
Therefore Taxonomic categories of Y-Chromosomes are defined by SNP
mutations. (...that's in essence what Diana is saying).

Perhaps it is better to say: The Y-DNA biological tree is not defined by
SNP's ,.. but haplogroups and sub-haplogroups (taxonomy) ie. the
taxonomy/nomenclature tree ARE defined by SNP's.

Ken and Vince are using "clade" to refer variously to both the biological
tree and the nomenclature tree. Diana is primarily referring to the
nomenclature and cladistic tree.

The tree house analogy:

There is an old ancient tree, and a tree house is built around it like a
scaffold.

Tree houses are built around trees using special methods of carpentry.
The tree is like the family tree of human Y-DNA variation, the tree house is
the YCC tree... and the method of carpentry is cladistics (which is a
specific method of phylogenetics)

In the YCC carpentry method, the architects have decreed that the method of
nailing the treehouse boards around the tree is determined by SNP markers.
The blueprint that the architects produce to build the tree house is the
Cladistic tree. The SNP markers define how the tree house is constructed
around the tree (but don't change the underlying form of the real tree
underneath).

(.... and no,.. alas... the tree house doesn't have a lockable door to lock
Vince, Ken, Myself and Diana away in)....

Angela
(who currently has a sleeping toddler... aka. "Captain Chaos")


On Sun, Mar 14, 2010 at 2:18 PM, Vincent Vizachero <>wrote:

> You twist the focus here to the haplotree, because it suits your
> goal. Fine.
>
> But the "haplotree" is merely a subset of the true Y phylogeny. In
> the real world, clades require no "SNP mutations" to define them.
> They exist whether such SNPs exist or not.
>
> That self-referential "cladists" are self-absorbed enough to believe
> that the clade only exists AFTER they discover it is a source of
> amusement to me and confusion to many.
>
> VV
>
>
>
> On Mar 13, 2010, at 6:18 PM, Diana Gale Matthiesen wrote:
>
> > 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.
>
>
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