COPENHAGEN, DENMARK—The Guardian reports that evolutionary geneticist Eske Willerslev of the University of Copenhagen conducted a population analysis of 83 Indigenous Australians and 25 Papuans, and found that their ancestors can be traced back 50,000 years, to the first arrivals on the continent. “They are probably the oldest group in the world that you can link to one particular place,” he said. The study also suggests that about four percent of the Indigenous Australian genome came from an unknown human relative. Willerslev added that Indigenous populations in Australia remained almost totally isolated until about 4,000 years ago, about the same time that the languages now spoken by these populations began to spread. “You see a movement of people spreading across the continent and leaving signatures across the continent,” he said. “That is the time that this new language has spread.” For more on the prehistory of Australia, go to "The Rock Art of Malarrak."