BOB HIRSHON (host):
A tale of two snakes. I’m Bob Hirshon and this is Science Update.
Pythons and boa constrictors look alike, but they’re not kissing cousins. DNA studies show they haven’t shared a common ancestor since dinosaurs roamed the Earth. Biologist Damien Esquerré at The Australian National University reports in Ecology Letters that evolution led to the look-alikes.
DAMIEN ESQUERRÉ (The Australian National University):
When a snake independently faces the same challenges, it will evolve the same solutions.
He compared dozens of boas and pythons and found remarkable similarities between those that evolved in similar environments. Aquatic pythons in Australia mirror aquatic boas in South America. Australian tree pythons are twins to African tree boas. It’s called convergent evolution, and DNA testing has revealed that it is responsible for the similarity between many organisms once thought to be related. I’m Bob Hirshon, for AAAS, the science society.
Story by Bob Hirshon