31 August 2012 Last updated at 02:17 ET By Helen Briggs BBC News

The DNA of a cave girl who lived about 80,000 years ago has been analysed in remarkable detail.

The picture of her genome is as accurate as that of modern day human genomes, and shows she had brown eyes, hair and skin.

The research in Science also sheds new light on the genetic differences between modern humans and their closest extinct relatives.

The cave dweller, a Denisovan, was a cousin of the Neanderthals.

Both groups of ancient humans died out about 30,000 years ago, but have left their mark in the gene pool of modern people.

The Denisovans have mysterious origins. They appear to have left little behind for palaeontologists save a tiny finger bone and a wisdom tooth found in Siberia's Denisova cave in 2010. Though some researchers have proposed a possible link between the Denisovans and human fossils from China that have previously been difficult to classify.

A Russian scientist sent a fragment of the bone from Siberia to a team led by Svante Paabo at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

He thought it might belong to an early modern human, but the results came as a surprise.

DNA analysis revealed a human who was neither a Neanderthal nor a modern human but the first of a new group of ancient humans.

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Cave girl's DNA gives up secrets