--- Dann Pigdon <dannj@alphalink.com.au> wrote: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...
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).
Dann Pigdon GIS / Archaeologist http://www.geocities.com/dannsdinosaurs Melbourne, Australia http://heretichides.soffiles.com ___________________________________________________________________