The nature of cladistics [...]
jcclark-lists at EARTHLINK.NET
Fri Nov 19 06:53:34 CST 2004
on 2004-11-19 06:21 pierre deleporte wrote:
> Can there be
> "processes" affecting a phylogeny?
Differences in speciation and extinction rates. Differences in inherited
capacity for morphological change (the inverse of which is sometimes
called "developmental canalization"). Differences in the inherited
features that influence niche breadth, generation time, and all those
other things that shape the fates of lineages. And then the totally
random things that also affect individuals and populations.
Perhaps it's a human construct to say that pterosaurs and glossopterids
are gone, but turtles and ginkgoes remain. And there are people that
think evolution only happens at a single level (although they can't seem
to agree whether that level is the gene, the individual, or the
population). But if we discount processes affecting clades, we shall
surely never see them.
Curtis Clark http://www.csupomona.edu/~jcclark/
Web Coordinator, Cal Poly Pomona +1 909 979 6371
Professor, Biological Sciences +1 909 869 4062
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