Really, really ancient mariners

The hand stencil on the wall of Liang Metanduno is, so far, the oldest evidence of our presence in Wallacea, the group of islands stretched between the continental shelves of Asia and Australia. Populating these islands is “widely considered to have involved the first planned, long-distance sea crossing undertaken by our species,” wrote Oktaviana and his colleagues.

Back when the long-lost artist laid their hand on the wall, sea levels were about 100 meters lower than they are today. Mainland Asia, Sumatra, and Borneo would have been high points in a single landmass, joined by wide swaths of lowlands that today lie beneath shallow ocean. The eastern shore of Borneo would have been a jumping-off point, beyond which lay several dozen kilometers of water and (out of view over the horizon) Sulawesi.

The first few people may have washed ashore on Sulawesi on some misadventure: lost fishermen or tsunami survivors, maybe. But at some point, people must have started making the crossing on purpose, which implies that they knew how to build rafts or boats, how to steer them, and that land awaited them on the other side.

Liang Metanduno pushes back the timing of that crossing by nearly 10,000 years. It also lends strong support to arguments that people arrived in Australia earlier than archaeologists had previously suspected. Archaeological evidence from a rock shelter called Madjedbebe, in northern Australia, suggests that people were living there by 65,000 years ago. But that evidence is still debated (such is the nature of archaeology), and some archaeologists argue that humans didn’t reach the continent until around 50,000 years ago.

“With the discovery of rock art dating to at least 67,800 years ago in Sulawesi, a large island on the most plausible colonization route to Australia, it is increasingly likely that the controversial date of 65,000 years for the initial peopling of Australia is correct,” Griffith University archaeologists Adam Brumm, a coauthor of the recent study, told Ars.