From The Economist:
The story of the ascent of man usually casts Australia as the forgotten continent. Both archaeology and the genes of aboriginal Australians suggest that a mere 15,000 years were required for humanity to spread from its initial toehold outside Africa, on the Arabian side of the straits of Bab el Mandeb, to the land of Oz. The first Australians thus arrived about 45,000 years ago. After that, it took until 1788, when Captain Arthur Phillip, RN, turned up in Sydney Cove with a cargo of ne’er-do-wells to found the colony of New South Wales, for gene flow between Australia and the rest of the world to be resumed.
This storyline was called into question a few years ago by the discovery, in some aboriginal Australian men, of Y chromosomes that looked as though they had come from India. But the details were unclear. Now a study by Irina Pugach of the Max Planck Institute for Evolutionary Anthropology, in Leipzig, and her colleagues, which has just been published in the Proceedings of the National Academy of Sciences, has sorted the matter out. About 4,000 years before Captain Phillip and his merry men arrived to turn the aboriginals’ world upside down, it seems that a group of Indian adventurers chose to call the place home. Unlike their European successors, these earlier settlers were assimilated by the locals. And they brought with them both technological improvements and one of Australia’s most iconic animals.