Re: Various topics

[Tom Holtz <tholtz@geochange.er.usgs.gov>]

>While I do not really believe bakker's hypthothis to be the sole cause,
>i must challenge tom holtz about his comment about hard evidence.
>i must ask him what hard evidence we could really expect to find.
>many diseases leave little pathology on the hard skeleton.  usually,
>only prolonged diseases (those that match the bone replacement cycle
>in length, like arthritis, syphilis, osteoporosis, etc.) or diseases that
>produce breaks (most virus and bacteria don't cause animals to go out
>and break any one bone (if any) consistently).  given that what kind of
>hard evidence could we expect?  parasites are notorious poor at getting
>into the fossil record (worse by far than vertebrates).
>
>Tom your ball....
>b

My point is - if there is no good potential for hard evidence, then how can
we test (falsify) this hypothesis?  It might indeed have been true that
disease played a role, but unless there is some way to verify it in the
fossil record, there isn't much of a way to say "yea" or "nay".

                                
Thomas R. Holtz, Jr.                                   
tholtz@geochange.er.usgs.gov
Vertebrate Paleontologist in Exile                  Phone:      703-648-5280
U.S. Geological Survey                                FAX:      703-648-5420
Branch of Paleontology & Stratigraphy
MS 970 National Center
Reston, VA  22092
U.S.A.