An 100-year-old lock of hair has helped scientists to unravel the movements of early humans on their journey to Australia. Scientists have obtained a genomic sequence from the hair, donated in the early 20th century by a man who was an Aboriginal Australian.

The genome reveals that, while we knew when humans first arrived in Australia, our knowledge of how they got there was a bit more patchy. An international collaboration of scientists, involving researchers at Imperial as well as University College London and the University of Cambridge, worked on sequencing the genome.

There is strong archaeological evidence to suggest that humans were in Australia 50,000 years ago. The new genome reveals that Aboriginal Australians are descended from humans that left Africa between 62,000 and 75,000 years ago, long before the humans that modern Asians and Europeans descended from left.

The previous most widely held theory was that all modern humans come from a single wave of migration out of Africa, but the new findings show this not to be the case.

New sequencing technologies have made it easier to sequence and compare the genomes of individual people from geographically distinct populations, enabling scientists to work out more about the movements of early humans than ever before. Dr Francois Balloux, who lead the UK team on this project, said: “The science of genomics makes a unique contribution to our understanding of when and how humans colonised the world.”

The genome shows no genetic input from modern European Australians. It supports the idea that present-day Aboriginal Australians descend from the first humans to occupy Australia and means that they represent one the the oldest continuous populations outside Africa.

Professor Eske Willerslev from the University of Copenhagen, who led the study, said: “While the ancestors of Europeans and Asians were sitting somewhere in Africa or the Middle East, yet to explore their world further, the ancestors of Aboriginal Australians spread rapidly; the first modern humans traversing unknown territory in Asia and finally crossing the sea into Australia. It was a truly amazing journey that must have demanded exceptional survival skills and bravery.”