In the gallery below, get an up-close look at the Aboriginal Australian hair specimen behind this landmark study. Then, in the Q&A with co-author and University of California, Berkeley biologist Rasmus Nielsen that follows, learn more about the backstory of this sample, how genome-sequencing works, and the technology that led to these discoveries.

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What were your team's key findings, and why are they so significant?

Anthropologists have long been interested in finding out how humans have dispersed. Most agree that modern humans evolved in Africa about 50 to 100 thousand years ago and thereafter spread to the rest of the world. But the consensus stops there.

Some anthropologists believe in the hypothesis of a so-called Southern Route or the idea that Aboriginal Australians descended from an early wave of dispersal of modern humans through Southern Asia. Most other population groups outside Africa are, according to this theory, descendants of a separate, more recent wave of dispersal. But others believe there was only one major wave. It has also been hotly debated if Aboriginals living in Australia today descend from the modern humans we know were in this area 50,000 years ago.

To resolve these debates, we sequenced the genome of an Australian Aboriginal using a 90-year-old hair sample. We analyzed the DNA computationally, and compared it to genomes of individuals from other geographic regions. We found that this individual must have descended from an early dispersal wave different from the one leading to East Asians and Europeans and that humans dispersed in two major waves of migration out of Africa. Our results also confirm that Aboriginal Australians are descendants of the first wave of migrants reaching Australia.

What is the backstory behind this hair specimen?

I was not involved in the acquisition of the hair sample, but I've been told that it's from the Duckworth Laboratory collections at University of Cambridge. It was obtained by one of the most distinguished anthropologists of his generation, Dr. Alfred Cort Haddon, in 1923.

According to Haddon's notes, the sample was obtained at Golden Ridge, near Kalgoorli in Western Australia, and the donor is described as a young man. We have worked together on this with the Goldfields Land and Sea Council, which represents the Aboriginal traditional owners of the Goldfields region, including the cultural -- and, possibly, the biological -- descendants of the individual who gave the original sample.

How does genome-sequencing work?

Perhaps I can explain it using an analogy. The genome has been compared to a book with three billion letters. By sequencing the genome of the Australian Aboriginal individual, we managed to find all the letters in the book. We still don't really understand the language the book is written in, but we can compare it to similar books, or genomes, from other populations to learn about differences and similarities between the populations.