Podcast: Cracking the smell code, why dinosaurs had wings before they could fly, and detecting guilty feelings in altruistic gestures

This week, we chat about why people are nice to each other—does it feel good or are we just avoiding feeling bad—approaches to keeping arsenic out of the food supply, and using artificial intelligence to figure out what a chemical smells like to a human nose with Online News Editor David Grimm. And Stephen Brusatte joins Alexa Billow to discuss why dinosaurs evolved wings and feathers before they ever flew. And in the latest installment of our monthly books segment, Jen Golbeck talks with Bill Schutt, author of Cannibalism: A Perfectly Natural History.  

Listen to previous podcasts.

[Image: Todd Marshall; Music: Jeffrey Cook]