This isn't 'evolution' at all--it's patently pro-evolution lies put forth as 'science.' Bigheaded snakes can eat big poisonous things and die. Smaller specimens of the same species then survive--the 'fittest' paradoxically being the smallest and presumably weakest...although presumably also the toads are smaller when young and could be swallowed by smaller snakes. (Read "The Andromeda Strain" ...) Breeders have made miniature horses, miniature pinschers, poodles etc. by similar selective breeding. You show me a snake that can type Othello or sing Sorrento--or a dolphin that's built an underwater hospital--and I'll give a little credence to the hypothesis of evolution.
LOL
I just have to laugh at the Evotards...sorry...BWAHAHAHAHAHAHAHAHAAAAAAAAA!
Your explanation sounds like 'survival of the fittest'. How is it different?