I agree with Physignathus. It's no coincidence that rattlers only evolved in such a large plains area occupied by large grazers. The ones that didn't have rattles were soon being picked out of bison hooves. All it took was a primitive rattle with some volume, and that animal would be avoided by most land animals. Obviously a stampede wouldn't be affected, but grazing animals would soon associate that sound with another of their herd falling over dead.



Yes, there are large savannah areas in Africa, but not the size of the great plains. Also, the same evolutionary path does not HAVE to be followed in other areas, although it can happen.
-----
1.1 Blackheaded pythons

1.1 Woma (Juvie female)

2.1 Aussie Olives

1.1 Timors

1.0 Angolan Juvie

1.1 Savu

1.1 Juvie Bloods

1.1 Juvie Balls

1.1 IJ Carpets

1.1 Coastal Carpets

1.2 Macklotts

1.1 Papuan Olives

0.1 Jungle Carpet

2.2 Scrubs (on breeding loan)

1.0 Jungle/Diamond cross

0.1 child, CB

0.1 wife, WC

[ Show Entire Thread ]