Where Did Whales Come From?


When you’re watching the actions of the biggest creatures on earth, ask about what animals they are related to. Are they fish? Are they related to sharks? Are they related to cows and camels?

If you said yes to the last question, you are right! Some scientists believe that the whale’s oldest ancestor is a four-legged, hyena-like animal that lived on land more than 50 million years ago.

It took about ten million years for the changes to happen. During that time the animal began spending more and more time in the water, where it had little competition for food. As it changed to a whale, its body shape became more streamlined so that it could move through the water faster. It also lost most of its hair and instead developed a layer of fat, or blubber, to keep warm. Its head changed shape so that it could see and breathe easily on the top of the water. Its eyes moved to the sides of its head and its nose moved from the front of its face, where yours is, to the top of its head.

When you’re looking at the whales, try to find its nose, the blowhole. Some kinds of whales have two blowholes and some have one. Whales in the waters around Cape Cod that have one blowhole are pilot whales and all kinds of dolphins. Humpback whales, minkes, and right whales have two blowholes.

Think about how you breathe when you are swimming: you have to lift your head out of the water. But a whale can keep most of its head in the water, watching for food, or looking after it’s young while it is breathing.