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Re: Limb Evolution - "Old" genes

On Thu, 24 May 2007, John Conway wrote:

Colin McHenry wrote:
Has anyone got a definition of Living Fossil that they think works?

How about a kronophylognetic definition:

"Any species that is more closely related to a fossil organism more than 30 million years old than it is to any other living species."

Howzat? Completely arbitrary but it seems to work if you ignore the species problem.

30 million years? Would it not suffice to say "related to an extinct organism"? Course, that would cover, say dodos...