Show Details

Snakes vs. Newts

April 1, 2008

Eating a toxic newt could kill a human, so why can some hungry snakes get away with it?


It’s a snake-eat-newt-world. I’m Bob Hirshon and this is Science Update.

North American Taricha newts harbor the same deadly toxin as the infamous Japanese pufferfish. Tetrodotoxin, or TTX, kills its victims by suffocating them. But evolutionary ecologist Charles Hanifin of Stanford University says garter snakes prey upon the noxious newts. He and his colleagues found that in the areas where newt toxicity is highest, snake populations have evolved a kind of super resistance.

CHARLES HANIFIN (Stanford University):
The snakes were so resistant, that they could easily eat any of the toxic newts in these populations and suffer no consequences.

He says a single mutation in one of the snake’s genes is responsible for their elevated resistance. In other areas where newts are less toxic, the snakes aren’t as resistant to the toxin. I’m Bob Hirshon, for AAAS, the science society.