Why did our ancestors ditch the shell and start growing babies inside their bodies instead? In this episode of Big Ideas, ...

Platypuses are weird looking. They look like someone stitched together a duck and a beaver—flat bill, webbed feet, and a ...

Q. When we studied high school biology, our teacher said more than 99 percent of animals lay eggs and only a few give live birth. That percentage seems too high. Humans, dogs, cats and cows are ...

Snakes, like most reptiles in the world, are oviparous. This means that rather than producing live young ones, the way mammals do, snakes produce an immature single cell — an egg. Most snakes follow ...

Add Yahoo as a preferred source to see more of our stories on Google. Animals reproduce in a variety of fascinating ways. Some species, including humans and many other mammals, give birth to live ...