Why Did Snakes Lose Their Legs? And 9 More Animal Mysteries

There are more than 1.5 million known zoological species on Earth, with at least as many enigmas. Here are our top 10.

By Emily Anthes and Stella Raine Chu · The New York Times – World

There are more than 1.5 million known zoological species on Earth, with at least as many enigmas. Here are our top 10.