Research by a team of anthropologists and biologists suggests that the domesticated bottle gourds widely used by prehistoric peoples were likely brought to the Americas some 10,000 years ago from Asia. Since bottle gourds are thought to have originated in Africa, the previously held theory was that the gourds had floated across the Atlantic ocean from Africa and were picked up and used as containers once they reached the Americas. Genetic comparisons showed that the gourds found at archaelogical sites in the Americas were a closer genetic match to modern-day gourds in Asia. The current research suggests that these bottle gourds may have been brought in boats from Asia, hand-carried across a land bridge, or floated across the Bering Strait.
The gourds of northeastern Asia were originally transported by humans from their native Africa. When humans harvest, store, and plant seeds over a sustained period, the plant populations adapt through genetic and morphological changes making it possible to distinguish the populations from the various regions. In addition to providing information about the origin of American gourds, it is interesting to note that this research shows that the bottle gourd -- essentially a container, not a food crop -- is the earliest known domesticted plant grown here. Radiocarbon dating indicates that gourds were used as containers in the New World for at least 9000 years.
The collaborative research was done by scientists from Harvard University, the Smithsonian Institution's National Museum of Natural History, Massey University in New Zealand and the University of Maine. The full report is available online on the website of the Proceedings of the National Academy of Sciences. Go to: http://www.pnas.org/cgi/content/full/102/51/18315