GENEALOGY-DNA-L Archives

Archiver > GENEALOGY-DNA > 2008-10 > 1224031686


From: "RICHARD KENYON" <>
Subject: Re: [DNA] What is a clade?
Date: Tue, 14 Oct 2008 17:48:06 -0700
References: <006601c92e07$1a005d10$6400a8c0@Ken1><68B69D8CE0C54829B29602D44B50508F@HP><A08066CE-2925-41F6-AD99-F778C8955486@vizachero.com>
In-Reply-To: <006601c92e07$1a005d10$6400a8c0@Ken1><68B69D8CE0C54829B29602D44B50508F@HP><A08066CE-2925-41F6-AD99-F778C8955486@vizachero.com>


The term, clade, can apparently be used in more than one sense. I frequently refer to the book, "A Dictionary of Genetics", 7th ed., 2006, by Robert C. King, et al, publ. by Oxford Univ. Press. Here's their entry for clade:

clade. 1. in classification, any group of organisms that is defined by characters exclusive to all its members and that distinguish that group from all others. 2. in evolutionary studies, a taxon or other group consisting of a single species and its descendents; a holophyletic group; a set of species representing a distinct branch of the phylogenic tree. Graphically a clade includes the species represented by the node and all branches that spring from it. See cladogram, PhyloCode.

I would interpret this to mean that a clade could be a group of similar haplotypes (def. 1) or a haplogroup and all its subhaplogroups (def. 2).

This reference defines cladogram as follows:

cladogram a branching diagram that displays the relationship between taxa in terms of their shared character states and attempts to represent the true evolutionary branchings of the lineage durings its evolution from the ancestral taxon. [this is followed by an example with accompanying diagram].

Haplogroup is not defined in this reference.


This thread: