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Science

Evolution

Evidence for evolution - fossils

Fossils of ammonites - sea creatures that became extinct about 65 million years ago

Most of the evidence for evolution comes from the fossil record. Fossils show how much, or how little, organisms have changed over time. One of the problems with the fossil record is that it contains gaps. Not all organisms fossilise well, and there will be many fossils that have been destroyed by the movements of the Earth, or simply not yet been discovered.

The horse

One of the few animals for which we have a fairly complete evolutionary record is the horse. All the main stages of the evolution of the horse have been preserved in fossil form.

Watch

BBC Nature video

Watch this tiny primitive horse, propaletherium, foraging for food in a forest.

Over 60 million years, the horse evolved from a dog-sized creature that lived in rainforests into an animal adapted to living on the plains and standing up to 2 metres high.

In the process its multi-toed feet, that were adapted for walking across the forest floor, evolved into single-toed hooves more suited for running over open country.

The evolution of the horse

time periodheight

Modern horse

1 million years ago1.6 metres
the pliohippus is similar to a modern day donkey

Pliohippus

10 million years ago1.0 metres

Merychippus

30 million years ago1.0 metres

Mesohippus

40 million years ago0.6 metres
the eohippus is a dog-like creature with an arched back, short neck and legs, and a long tail

Eohippus

60 million years ago0.4 metres

Back to Evolution and environment index

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