Toxicity is a good defense, until it isn't

Imagine, you’re a toxic toad hanging around South America. No other animals are gonna mess with you, right? After all, you’re ~toxic~! So if anyone tries to eat you, they’ll be exposed to something called a cardiotonic steroid — and may die of a heart attack. Well, unfortunately, for you, some animals have developed adaptations to these toxic steroids. Evolutionary biologist Shabnam Mohammadi has spent her career studying how these adaptations work — and says even humans have used these toxins to their advantage since ancient Egypt. So today on Short Wave, we get a little… toxic (cue Brittney Spears). Host Regina G. Barber talks to Shabnam about how some predators can get away with eating toxic prey. Curious about biology? Email us at shortwave@npr.org.Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.