Earliest Musa banana from the late Quaternary sequence at Fahien Rock Shelter in Sri Lanka

The domestication and the time of arrival of bananas in South Asia and Africa are unresolved issues. We provide banana seed and leaf phytolith evidence from the archaeological sequence at Fahien Rock Shelter, located in southwest Sri Lanka, to help understand the geographical configuration of hybridization, dispersal, cultural association and chronology of banana domestication. Phytoliths from this sequence indicate that Musa accuminata subspecies and M. balbisiana existed in the south western lowland rainforest of Sri Lanka from 44,952-47,854 cal. BP., and rock shelter occupants exploited those taxa, possibly for starchy food. Edible diploid (AA) bananas may have introduced from elsewhere, possibly from Indonesia or PNG before 5,994-6,194 cal. BP. From this time onwards, phytoliths morphologically identical with those from triploid banana cultivars (AAB and ABB) appeared in the lowland rainforest of south western Sri Lanka. This precocity appears unique to Sri Lanka. Dispersal of these triploids to the east coast of Africa may have followed maritime trade networks in the Indian Ocean from the first half of the sixth millennium BP. Northward dispersal, e.g. to urban Harappan sites, happened in the middle of the fifth millennium BP. Sri Lanka’s location in the Indian Ocean is thus important for understanding banana domestication and dispersal. This discovery shows the interconnection of prehistoric cultures and their engagement with the management of starchy staples in the lowland rainforests of Sri Lanka.