Looking at Tardigrade Sperm and Other Reproducing Swimmers - S4.E14

Original Title: Tardigrade Sperm and Other Reproducing Swimmers

Not all hypotheses need to be good. In fact, many of them are terrible. It’s just that when you’re trying to understand the world, you might find yourself believing that there are tiny humans living inside the heads of sperm, and we're here to tell you, that's not how it works.