DNA analysis of the remains of a Neanderthal has revealed interbreeding with humans took place much earlier than originally thought. The findings – published in journal Nature – suggest modern humans were present outside Africa some 100,000 years ago, 40,000 years before previous estimates.

The discovery has huge ramifications for how scientists calculate the movements and development of our species, Homo sapiens.

The Neanderthal remains were discovered in a remote cave in the Altai Mountains – in southern Siberia close to the border with Mongolia.

Analysis of the female specimen revealed small amounts of human DNA present in her genome. It suggests interbreeding between the two species happened before the time she was alive, 100,000 years ago.

Previous estimates had placed modern humans outside of Africa not before 65,000 years ago.

The exciting finding has spawned new theories on the patterns of migration for our early ancestors. One such involves the idea of a so-called “failed-dispersal” – that groups modern humans had left Africa earlier than previous estimates, but failed to establish themselves properly. Interbreeding took place, but Neanderthals remained the dominant geographical species.

Geneticist Martin Kuhlwilm reported to Reuters that these early traveling human populations probably went extinct due to competition from the Neanderthals, or possibly “environmental factors”.

Scientists now think Homo sapiens could have been in areas including modern-day Lebanon, Cyprus, Syria and Turkey up to 125,000 years ago. The Siberian specimen was found much further north, in a place much milder than that found today.

It’s widely recognised modern humans migrated north and interbred with Neanderthals in present Europe and parts of Asia. Modern humans and Neanderthals split away from each other genetically around 600,000 years ago.

Neanderthals – who went extinct around 40,000 years ago – were effective hunters, much more heavily built than modern man and with thickset features. It’s estimated people of European and Asian heritage still possess around 2% of Neanderthal DNA.