When Dutch explorers first arrived in Australia in 1606, they found they’d been beaten to it. But where did these indigenous Australians come from themselves? LiveScience:

Even the indigenous, or aboriginal, population in 1788 is a bit of a mystery, with estimates of the population ranging from 250,000 to 1.2 million. Further back, the story of Australia’s human population is shrouded, though gene studies suggest a relatively large founder population would have been necessary to result in the genetic diversity seen today.

Now, new research indicates that between 1,000 to 3,000 people originally made the trek some 50,000 years ago. And rather some chance encounter with the continent down under, researchers think that the original migrants set out to deliberately colonize Australia.

To arrive at the new discovery, researchers used nearly 5,000 radiocarbon isotopes from 1,750 ancient cooking, burial and settlement sites around the contient to reconstruct the past migration events. ScienceNOW explains what they found:

Relying on the radiocarbon-date database, Williams worked out the rates at which the population changed over time. Then he back-calculated from the aboriginal population at the time of the first European settlement in 1788. He found that for the aboriginal population to reach the estimated 770,000 to 1.2 million at the time of settlement (it’s roughly 460,000 today), the founding population that arrived in Australia roughly 45,000 years ago must have been between 1000 and 3000 people.

In other words, the researcher told ScienceNOW, Australia’s original migrants weren’t just a family or two who got shipwrecked on the continent.

More from Smithsonian.com:

Indians Made it to Australia More than 4,000 Years Before the British

Contemporary Aboriginal Art