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Re: komodos

Hans Havermann wrote:

>Not at all. My questions were pretty tangential to your info and were
>prompted less by your message than by seeing a few minutes of a show
>called "Komodo Dragons: Last of the Dinosaurs" on the Canadian
>Discovery channel.  Apparently, a komodo is able to *outrun* its prey,
>a very unlizard-like behaviour! I think they mentioned some Japanese
>scientists doing some blood analysis but I wasn't too intent on the
>show and am reluctant to reconstruct my memory of it. I had hoped my
>message might prompt details from people who had access to such.

Have you ever chased a lizard before?  They can be FAST!!

Absolute speed is not always a good measure of the difference between
endotherms and ectotherms.  As Ruben pointed out in the 1990-ish
Archaeopteryx paper in Evolution, ectothermic muscle can generate more power
than endothermic muscle.  However, ectothermic muscle is strictly anaerobic,
so that it can tire more easily and requires longer recovery times.
Although endothermic muscle cannot produce as much power, they can work
aerobically, and have quicker recovery times.

So, lizards today can outrun many similar sized (or larger...) endotherms,
but cannot run as far, for as long, or as often as an endotherm.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661

"To trace that life in its manifold changes through past ages to the present
is a ... difficult task, but one from which modern science does not shrink.
In this wide field, every earnest effort will meet with some degree of
success; every year will add new and important facts; and every generation
will bring to light some law, in accordance with which ancient life has been
changed into life as we see it around us to-day."
        --O.C. Marsh, Vice Presidential Address, AAAS, August 30, 1877