By WILSON da SILVA
SYDNEY, Australia - The discovery of 30,000-year-old tools in Papua New Guinea with crop residues suggests that Pacific islanders were among the first humans to cultivate crops, Australian scientists say.
“Until recently, to suggest there was human occupation anywhere in the Pacific beyond a few thousand years ago, you’d be laughed out of a seminar,” says archeologist Thomas Loy of Canberra’s Australian National University.
“But in the last few years . . . in Papua New Guinea, the Solomon Islands and other sites . . . the evidence has been there that people were regularly harvesting major crops between 20,000 and 30,000 years ago.”
Evidence recently excavated by Loy’s colleague, anthropologist Peter White of the University of Sydney, and by others is challenging the traditional view that agriculture was developed in Israel and Mesopotamia, now Iraq, some 10,000 years ago.
Theories about the rise of farming have relied on relics like channel systems for crop irrigation, murals and documents depicting agriculture - evidence that is rare in the Pacific.
But in the past few years, researchers have analyzed Stone Age tools with microscopes and some samples have revealed a multitude of plant residues that could only have come from cultivated crops, Loy says.
The evidence shows that rather than just growing crops, Pacific peoples were long ago harvesting, pulping and shredding roots, and then roasting them to make them edible - regarded as advanced behavior for humans of the time.
Aside from the microscopic evidence, Loy says the fact the plants were eaten at all suggests advanced harvesting. The area’s favored root crops of taro and bracken fern are bitter in taste and mildly toxic, and must be pounded, shredded and cooked to make them safe and edible.
The finds follow a recent study suggesting that aboriginals had reached northern Australia some 40,000 to 60,000 years ago. Human settlement and farming in the Pacific may stretch back that far, Loy says, but scientists are hampered by radiocarbon dating, a technique that is unreliable beyond 30,000 years.
The Australian national study used a new and expensive method called thermal luminescence dating, which stretches the time horizon much further back, Loy said.