Thick-skinned bottle gourds widely used as containers by prehistoric peoples were likely brought to the Americas some 10,000 years ago by individuals who arrived from Asia, according to a new genetic comparison of modern bottle gourds with gourds found at archaeological sites in the Western Hemisphere. The finding solves a longstanding archaeological enigma by explaining how a domesticated variant of a species native to Africa ended up millennia ago in places as far removed as modern-day Florida, Kentucky, Mexico, and Peru.

The work, by a team of anthropologists and biologists from Harvard University, the Smithsonian Institution’s National Museum of Natural History, Massey University in New Zealand, and the University of Maine, appeared on the Web site of the Proceedings of the National Academy of Sciences (PNAS).

Integrating genetics and archaeology, the researchers assembled a collection of ancient remnants of bottle gourds from across the Americas. They then identified key genetic markers from the DNA of both the ancient gourds and their modern counterparts in Asia and Africa before comparing the plants’ genetic makeup to determine the origins of the New World gourds.

“For 150 years, the dominant theory has been that bottle gourds, which are quite buoyant and have no known wild progenitors in the Americas, floated across the Atlantic Ocean from Africa and were picked up and used as containers by people here,” says Noreen Tuross, the Landon T. Clay Professor of Scientific Archaeology in Harvard’s Faculty of Arts and Sciences. “Much to our surprise, we found that in every case the gourds found in the Americas were a genetic match with modern gourds found in Asia, not Africa. This suggests quite strongly that the gourds that were used as containers in the Americas for thousands of years before the advent of pottery were brought over from Asia.”

The work was supported by the Smithsonian Institution and the National Museum of Natural History and by Harvard’s Department of Anthropology and Peabody Museum of Archaeology and Ethnology.