There are some 600 million cats in the world. Not all of them are pets — between 50 and 100 million in the U.S. — but cats share a fascinating history with humans. Washington University evolutionary biologist Jonathan Losos dives into that history in the new book, “The Cat's Meow: How Cats Evolved from the Savanna to Your Sofa.” Losos joins guest host Alex Heuer to talk about all things cats.