Are there some animals that have stopped evolving?

Some modern animals look just like their long-extinct ancestors. Have these "living fossils" really not changed in millions of years?

Presented by

Lucy Jones

The goblin shark is rarely seen, but when it does show up it makes headlines.

That's partly because of its unusual looks. Its pink flesh gives it the appearance of having been skinned, and a flattened, dagger-like snout protrudes from its head. No wonder it's been called the "alien of the deep".

But the goblin shark also evokes our imagination because of its special history. The family it belongs to, the Mitsukurinidae, seems to have barely changed in 125 million years. That means the goblin shark is a "living fossil", an animal that has survived seemingly unchanged for a huge span of time.

A living fossil will look just like a fossilised animal from millions of years ago. This seems to imply that, for these few species, evolution has stopped entirely – as if they evolved to such a peak of perfection that they just don't need to improve any more. But appearances can be deceiving, and there is more to these extreme survivors than meets the eye.

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