Succulent and sweet, bananas make an ideal snack--but they can also tell us a lot about human civilization. Such is the case with a new archaeological discovery, which indicates that Africans were harvesting the fruit as early as 4500 years ago. If correct, these findings would radically alter current assumptions about when agriculture came to the continent.
For people living in the tropics, bananas can be vital to daily survival. This is particularly true in Africa, which has very few native domesticable plants. Indeed, banana cultivation was the economic backbone of some African kingdoms that thrived before European colonization. Until recently, most African scholars assumed that the banana, which is native to New Guinea, was not introduced into Africa earlier than about 2000 years ago.
Now, work at an archaeological site in Uganda has challenged that assumption. A team consisting of Julius Lejju of Mbarara University in Uganda, Peter Robertshaw of California State University, San Bernadino, and David Taylor of Trinity College in Dublin, Ireland, analyzed sediment samples from the site of Munsa, about 125 kilometers northwest of Kampala. Earlier excavations at Munsa led by Robertshaw had shown that the site was first occupied by large numbers of people about 1000 year ago. Yet radiocarbon dating of the samples indicated occupation up to 4500 years ago. Fossil plant fragments, called phytoliths, of the banana genus Musa are present in these earliest levels, the team reports this month in the Journal of Archaeological Science.
The researchers say that this early date for banana cultivation is consistent with the findings of another team working at the site of Nkang, in southern Cameroon, which previously found evidence of banana cultivation dating back about 2500 years ago--a finding that was controversial at the time but which now, they say, seems much less so. Moreover, the researchers argue that recent work by an Australian team indicating that bananas were cultivated in New Guinea at least 6500 years ago (Science, 11 July 2003, p. 189) makes the early African dates all the more plausible. And genetic evidence from other studies suggests that bananas were first introduced from New Guinea into southeast Asia. From there sea traders could have brought them to East Africa across the Indian Ocean.
The results are "exciting," says David Schoenbrun, a historian specializing in Africa at Northwestern University in Evanston, Illinois. It remains to be seen if these very early banana farmers were the direct ancestors of later African agriculturists, he says, "or whether they were societies that disappeared and left little or no trace." The villages at Munsa, for example, had vanished by 1800 C.E.