Why is there only one human species?By Michael Mosley

Not so very long ago, we shared this planet with several other species of human, all of them clever, resourceful and excellent hunters, so why did only Homo sapiens survive?

Homo erectus survived on Earth for almost two million years

"There's such a huge gulf between ourselves and our nearest primate relatives, gorillas, chimpanzees and bonobos," said Dr Shea.

"If that gap were populated by other hominids, we'd see that gap as not so much a gulf but rather a continuum with steps on the way. We'd still think of ourselves as special, but maybe not so special - a little dose of humility wouldn't hurt.

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Sources

BBC @ http://www.bbc.co.uk/news/science-environment-13874671

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