Eggs helped animals conquer land—but most mammals stopped laying them. Why is that? Why do most animals lay eggs, while humans and most mammals give birth to live young? In this episode of Big Ideas ...

Why did our ancestors ditch the shell and start growing babies inside their bodies instead? In this episode of Big Ideas, from the team behind Deep Look, Niba zooms out to explore one of evolution’s ...

When we think of snakes, we usually imagine them laying eggs. But not all snakes do that! Some snakes actually give birth to live babies instead of laying eggs. This might sound unusual, but it’s a ...