for National Geographic News
Once considered a "Neolithic backwater" by archaeologists, Papua New Guinea is emerging as one of the handful of places on Earth where agricultural practices developed independently from other cultures.
The evidence reported June 19 on the Science Express website by Tim Denham, an archaeologist at Flinders University in Adelaide, Australia, and colleagues, may put an end to a long-standing debate on the origin of agriculture in the swampy highlands on the island nation.
"People were definitely exploiting plants, including taro, at Kuk Swamp approximately 10,000 calendar years before present," said Denham. "There is then-evidence of banana cultivation from 6,950 to 6,440 calendar years before present."
Taro (Colcasia esculenta) is a tuber with edible leaves and starchy roots. It remains a staple in the Papua New Guinean diet today.
Prior to this discovery, many scientists regarded Papua New Guineans as passive recipients of domesticated plants and animals from Southeast Asia. But the dates for the rise of agriculture documented by Denham and colleagues predate the earliest known Southeast Asian influence by about 3,000 years.
Katharina Neumann, an archaeobotanist at Johann Wolfgang Goethe-Universität in Frankfurt, Germany, writes in a related Science perspective that "only a few regions were geographically suited to become the homelands of full agricultural systems. New Guinea seems to have been one of them."
Denham and colleagues base their conclusions about the gradual rise of Agriculture in Papua New Guinea on a re-examination of the Kuk Swamp excavation site in the Wahgi Valley.
The site was first investigated in 1966 with subsequent excavations in the 1970s, but the details of the finds were never fully published and the evidence for agricultural practices were inconclusive, said Denham.
"The most serious problem was the absence of any remains of the plants which had been hypothetically exploited," said Neumann. "This is for a large part due to preservation, like in other humid, tropical regions."
But Denham and colleagues were able to find plant residues in the soils and on stone tools. According to the analysis of these residues, the researchers conclude that the Papua New Guineans were indeed exploiting taro and banana.
The team also dated features consistent with the planting, digging, and tethering of plants and localized drainage systems to 10,000 years ago. Mounds constructed to plant water-intolerant plants such as bananas, sugarcane, and yams are dated to about 6,500 years ago.
SOURCES AND RELATED WEB SITES