Scientists have rebuilt the entire genetic make-up of a girl who lived and died in a Siberian cave more than 50,000 years ago. The young woman belonged to a long extinct group of humans called Denisovans, their existence known only from meagre fossil remains uncovered at the Denisova cave in the Altai mountains in 2008. They are thought to have occupied much of Asia tens of thousands of years ago. Previous tests on the remains found they were more closely related to Neanderthals than modern humans. Writing in the journal Science , researchers in America and Germany describe how they sequenced the girl's entire genome with an accuracy that was once considered impossible with such ancient specimens. The final sequence matched the quality of modern genetic tests on living people. They sequenced single strands of DNA taken from a little finger bone found at the scene. The bone fragment, and two fossilised teeth, are the only remains of the Denisovans. Studies on the girl's genes suggest she had dark skin, brown hair and brown eyes, but other genetic factors help shed light on the Denisovans more broadly. Comparison of genetic material inherited separately from the girl's parents points to a population with very low genetic diversity, probably because the Denisovans started as a small group of pioneers and expanded rapidly. The team from Leipzig and Harvard Medical School compared the Denisovan genome with similar sequences from Neanderthals and 11 modern humans from around the world. The research highlighted scores of gene variants that are found in modern humans but not in Denisovans. "This is perhaps, in the long term for me, the most fascinating thing about this: what it will tell us in the future about what makes us special in the world," said Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzig.