What evolutionary advantage did snakes gain by losing their legs? © Getty Images

What evolutionary advantage did snakes gain by losing their legs?

Smooth and slippery, the debate on serpents losing their legs depends on whether you believe they were originally water or land dwellers.

Asked by: Rob Banino, Bristol

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It’s thought that snakes lost their legs 100 to 150 million years ago, but debate is still raging as to whether their limbed ancestors were aquatic or terrestrial.

The evolution of a long, legless body could be beneficial to life underwater as it would enable eel-like swimming. But it could also be beneficial on land, making burrowing and hunting underground easier.

Either way, we can still see traces of their legs today: boas and pythons, the most ancient surviving snakes, have tiny leg bones buried in the muscles towards their tail. The more advanced snakes, however, have lost them completely.

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