Ancient human relative explains mountain gene mutation

The fossilised remains of an early human cousin found in the mountains of Tibet proves mankind adapted to live at high altitude far earlier than previously thought, scientists said Wednesday.

A jawbone dating from at least 160,000 years ago of a Denisovan -- a now-extinct branch of humanity -- is the first of its kind discovered outside of southern Siberia, and experts believe it holds the key to understanding how some modern-day humans have evolved to tolerate low-oxygen conditions.

Contemporaries of the Neanderthals -- and like them, possibly wiped out by anatomically modern man, Homo sapiens -- the Denisovans first came to light a decade ago.

Their existence was determined through a piece of finger bone and two molars unearthed at the Denisova Cave in southern Siberia's Altai Mountains and dated to some 80,000 years ago.

But the new remains -- discovered in passing by a local monk nearly thirty years ago -- has led researchers to conclude that Denisovans were far more numerous, and