bad biogeography

John Grehan jgrehan at SCIENCEBUFF.ORG
Tue Jun 15 14:11:55 CDT 2004

I'll take a breather from the definitions question (I'll pick up on it
tonight or tomorrow) to draw attention to another favorite topic - bad
biogeography - or at least 'bad' as I would define it. In the May issue
of New Scientist there is an article titled "out of Asia' in which a
biogeographic scenario is made by Chris Beard according to his discovery
of anthropoid fossil primates in Asia having a necessary biogeographic
correlation according to Darwin's rules of centers of origin and
dispersal theory. 


This mode of biogeography is traditionally represented by the view that
the anthropoid primates evolved in Africa about 35 myr (date of the
oldest fossils) and later spread into Asia. In contrast, the 45 myr
fossils found in Burma and China were represented by Beard and his
supporters as evidence that the higher primates evolved in Asia and
later spread to Africa. 


This is the classic case of a center of origin being assumed, then the
location of the oldest fossil representing said center of origin and
later locations as the result of sequential dispersal events, and then
reassigning the center of origin according to new fossil finds, or
defending the old one based on different preferences such as rejecting
the phylogenetic position of the Asian fossils (which is what Ciochon,
Simons, and Gunnell did (concluding that the fossils were adaphids
rather than anthropoids). The objectors also took the other classic
approach by raising imaginary objections such as a sea barrier between
Asia and Africa preventing Asian primates from migrating to Africa. Of
course to that Beard imagines equally well that while it would be
'difficult' to cross the ocean, it would by no means be impossible if
there were giant stepping stones present. All of this without any
empirical evidence whatsoever as the oldest fossil actually makes no
statement other than a taxon existing in some form at some place at some
time. But in Darwinian biogeography imagination holds more weight than
actual evidence.



John R. Grehan
Director of Science and Collections

Buffalo Museum of Science

1020 Humboldt Parkway

Buffalo, NY 14211-1193

email: jgrehan at

Phone: (716) 896-5200 ext 372


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