In the last few years, improved dating methods have established Australia as home to modern humans dating back to 40,000 years and possibly even 60,000 years ago. But how did they get there? Scientists have long believed that Timor would be a good place to look for evidence of early migration, as trade winds would send boats straight to Australia's northwestern shores. But access to important sites was difficult during the 26 years of Indonesian rule that ended in 1999.

Last September, Matthew Spriggs and Sue O'Connor from Australian National University, Canberra, became the first Australian archaeologists allowed into the country since independence. Digging a pit in the Lene Hara cave in East Timor, they pulled out more than 400 pieces of chert, stone blades, and shell beads. They expected to find the material a few thousand years old--an unremarkable age. But when they sent material off for radiocarbon dating, they got a big surprise: The artifacts, they reported last week, yielded a minimum age of 35,000 years.

That's almost three times the age of the oldest known site in the country. "These dates are right at the limit of carbon dating; they may well be much older," says O'Connor. They mean "we are hot on the trail of the earliest human inhabitants of East Timor, who may well have been the ancestors of the earliest Australians," says Spriggs. The team plans to return to Timor this summer to look for more ancient sites, and ultimately to use other dating techniques, such as optically stimulated luminescence. If older sites are found, "this will change the way we think about colonization," says O'Connor.

Rutgers University geologist Carl Swisher says the finds at Timor are not surprising, given the evidence that humans had already made it to Australia as well as surrounding islands by then. Still, he says, "it's always exciting to have a new finding on a different island in the region to help us look at the stepping-stones to Australia."