The phrase "survival of the fittest" may evoke images of fast, strong, formidable beasts of land and sea, but that’s not entirely accurate. After all, humans have survived exceedingly well, and it only takes one well-placed swipe of a lion’s paw to take a person down.

On this episode of Misconceptions, host Justin Dodd is getting to the bottom of some common misunderstandings about evolution. If, for example, you think organisms always evolve to have more streamlined functions, you might be surprised to learn that one of the nerves connecting a giraffe’s brain to its voice box—which is less than 4 inches away—is about 13 feet long. And if you think evolution always progresses in a linear direction, you’ll almost certainly drop your jaw when you realize whales’ ancestors left water, learned to operate on land, and then trooped back into the ocean.

Watch the full video below to learn more about those and other evolutionary processes, and subscribe to the Mental Floss YouTube channel for more illuminating videos.