When Steve Gosser heard the song of a scarlet tanager in the woods, he knew to look for a bright-red bird with black wings. But when he laid eyes on the singer, he saw instead a dark-colored head, black-and-white body, with a splash of red on its chest. "Well, that sort of looks like a first-year male rose-breasted grosbeak," he said. The song of one bird coming out of the body of another suggested this little guy could be a rare hybrid. Gosser enlisted the help of some pros, including biologist David Toews, who conducted a genetic analysis to see if this was truly the offspring of two species that diverged 10 million years ago, and today run in very different circles. On today's episode, Gosser and Toews fill Aaron in on this avian mystery, and what hybrid animals can teach us about evolution.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy