Rattlesnake venom 'recipe' is rewritten by changing environments

Scientists have long known that the venom of each rattlesnake species is a distinct, constantly evolving chemical cocktail. Now, new research shows that the venom of rattlesnakes that live on Mexican islands with significant space and competition has evolved to be simpler and better tailored to their prey. Mark Margres of the University of South Florida discusses his findings with The World's Host Carolyn Beeler.