The Surprising Origin of Venom Revealed

Scientists used to believe that snakes evolved venom between 60 million and 80 million years ago. Lizards were said to have developed it around 100 million years ago, independent of their legless cousins.

But after comparing the genetic code for snake and lizard venom, Bryan Fry at the University of Melbourne, Australia discovered that the two reptiles shared nine toxins. This supports the idea that snakes and venomous lizards evolved from a common venomous ancestor, and after connecting the DNA dots, Fry and his colleagues traced venom to a single origin 200 million years ago.