Why do animals have things in common?

A tiny ant, a fluffy cat and a giant whale all seem completely different. But if you look closely, animals share lots of things. Why is that?

Every animal has the same needs

No matter how big or small, every single animal needs the same handful of things to live. They all have to eat to get energy. They all have to breathe. They all grow bigger over time. And they can all have babies, so there will be more of their kind. These shared needs join every animal together, from beetles to bears.

Family resemblance

Now look at animals in the same family. All cats — your kitten, a lion, a tiger — have whiskers, sharp claws and pointy ears. All birds have feathers, wings and a beak. Why so similar? Because animals in a family are related, a bit like cousins. They came from the same kind of ancestors long ago, so they are built in matching ways.

Same job, same tools

Often animals share a feature because it does the same useful job. Eyes for seeing, legs for moving, mouths for eating. When two animals need to do the same thing, nature often gives them similar tools — even if they are not close relatives at all.

Wonder fact: You share something with a banana! Every living thing carries instructions called DNA, and humans and bananas have roughly half of theirs in common.