How do new species form? How long does it take for evolution to happen? What can hybrids tell us about the process of speciation?

On this episode we talk with Peter and Rosemary Grant, two Princeton biologists who spent decades studying finches on the Galapagos Islands. Their work on bird beaks provides some of the strongest evidence for how fast natural selection can occur and more recently the genes involved. Their newest work on hybridization could fundamentally change how we think about speciation in animals.