How did an infertile fruit get to Africa so soon?BANANAS were being grown in West Africa 2500 years ago at least 1000 years before the accepted start of banana farming on the continent. The finding raises questions about how a plant from Asia reached what is now Cameroon so long ago.The evidence comes from microscopic silica fossils called phytoliths. Theyre mineral inclusions in plant tissue, explains Hans Beeckman of the Royal Museum for Central Africa in Tervuren, Belgium.No one knows their function, but the size and shape of each phytolith reveals which plant it came from. Beeckman and colleagues from Belgium and Cameroon found conical phytoliths in ancient rubbish pits in Cameroon and compared them with phytoliths from plants native to the region. They drew a blank at first, but eventually concluded they must have come from the cultivated banana, having ruled out an inedible indigenous relative called the red Abyssinian banana.We were surprised because we thought bananas were not grown in Cameroon during that era, says Beeckmans colleague Luc Vrydaghs. Cultivated bananas can only be grown from cutting s rather than seeds, so humans must have brought them to Africa from Asia, where they originated.The big question is who brought them, and how? [They] probably came for Indonesia and Asia by sea to Madagascar, then though eastern Africa and finally to Cameroon, says Beeckman. But weve done the botanical part, and anthropologists can now take in on, he says. One way to trace the banana trail might be to study old African languages and map the positions of ancient tribes with words for the banana. Nicholas David, professor of archaeology at the University of Calgary in Alberta, is mystified by the finding. He thinks bananas were not known even in East Africa until the 10th century AD. He adds that its possible bananas were brought by Indonesians who settle in Madagascar in the first century AD, introducing technology such as sewn boats and xylophones to Africas ease coast. But they would be too late to get them to Cameroon by 500 BC.