Re: Built Like a Race Horse, Slow as an Elephant?

[Dann Pigdon <dannj@alphalink.com.au>]

Graydon writes: 

> Cheetahs probably evolved as pronghorn antelope predators in Pliestocene NorAm,
> and it looks very much like there was a cheetah/pronghorn arms race for speed.

Actually, it was almost certainly a pronghorn/pronghorn arms race. There 
would always have been far more pronghorns than cheetahs, so cheetah 
predation on a population of slow coaches would still not have been enough 
to threaten their long-term survival. 

I doubt pronghorns would have evolved to run as fast as a cheetah (or as 
close as their biology would have allowed) just to avoid the occasional bit 
of cheetah predation. I think it's more likely that pronghorns evolved to 
run fast to compete with each other. 

It's like the old saying goes: if you and a friend are chased by a tiger, 
you don't have to outrun the tiger. You just have to outrun your friend... 

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Dann Pigdon
GIS / Archaeologist         http://www.geocities.com/dannsdinosaurs
Melbourne, Australia        http://heretichides.soffiles.com
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