Re: Cladistics in Science

[chris brochu <cbrochu@fmppr.fmnh.org>]

I haven't read it with tweezers yet, but here are some thoughts:

Their results support the notion that with very high, unbiased sampling,
stratocladistics works.  Since we know that stratigraphy should preserve
a phylogenetic signal at some level, this is not surprising.  But if you
look closely at the simulations they ran, the worst-case-scenario still
involves 10 percent sampling of extinct taxa.  This might work for some
marine invertebrates, but very few vertebrates will have sampling levels
that high.  Non-sampling seems to be random in their simulations, and we
know that geographic biases can be quite strong - so I don't think the
method they use will be applicable to the vast majority of terrestrial
vertebrate data sets.

More later, once I've read it in more detail.  Along with some comments
from the evolution/systematics meetings.


chris




gmbra@cygnus.uwa.edu.au wrote:
> 
> A recent issue of Science (11th June, Vol 284, 1999) has an article by Fox,
> Fisher and Leighton on a comparison of cladistics vs stratocladistics. It
> claims stratocladistics is much better at recovering the "real" phylogeny
> than conventional cladistics is. Trouble is, I don't understand enough
> cladistics to evaluate the conclusions. It would be most informative if one
> or more of the cladistic experts on this list could post a potted summary
> of this paper and their response to the conclusions and implications (if
> any) for dinosaur phylogenies. I'm sure I'm not the only one who would be
> interested in your views. Any takers?
> Thanks
> Graeme Worth

-- 
----------------------
Christopher A. Brochu
Department of Geology
Field Museum of Natural History
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Chicago, IL 60605

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