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Re: up!up!up!and away!
In a message dated 3/21/99 4:08:45 PM EST, Philidor11@aol.com writes:
<< Is that all or most of the characters that keep it in the clade? This does
raise the question of how many characteristics an animal has to be 'missing'
to be outside the clade. Is there a general principle that says an animal in
direct line of descent (probably) is so different from prior examples that a
new clade is needed? >>
Clades are defined by descent, not by characters. Characters are used to
support a hypothesis that a particular organism belongs to a particular clade.
Once in a clade, an organism and all its descendants to the end of time remain
part of that clade. The issue of whether or not to employ clades as taxa is