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

[Andrew Simpson <deathspresso@yahoo.com>]

--- Dann Pigdon <dannj@alphalink.com.au> wrote:

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

I'm not sure I'm following you Dann. How are the
Pronghorns evolving speed? Are you saying that the
North American Cheetah are or are not responsible?
Because the Proghorns can't make themselves faster and
have no reason too unless something is chasing them or
if there is an advantage to getting somewhere quicker.
(A quickly dwindling food source perhaps). 

Andrew S.



 
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