hybridization events produced the triploid cultivars of bananas commonly grown today. From Island Southeast Asia, they became part of the staple domesticated crops of Austronesian peoples and were spread during their voyages and ancient maritime trading routes into Oceania, East Africa, South Asia, and Indochina. These ancient introductions resulted in the banana subgroup now known as the "true" plantains, which include the East African Highland bananas and the Pacific plantains (the Iholena and Maoli-Popo'ulu subgroups). East African Highland bananas originated from banana populations introduced to Madagascar probably from the region between Java, Borneo, and New Guinea; while Pacific plantains were introduced to the Pacific Islands from either eastern New Guinea or the Bismarck Archipelago. Phytolith discoveries in Cameroon dating to the first millennium BCE triggered an as yet unresolved debate about the date of first cultivation in Africa. There is linguistic evidence that bananas were known in Madagascar around that time. The earliest prior evidence indicates that cultivation dates to no earlier than late 6th century CE. It is likely, however, that bananas were brought at least to Madagascar if not to the East African coast during the phase of Malagasy colonization of the island from South East Asia c. 400 CE. Glucanase and two other proteins specific to bananas were found in dental calculus from early Iron Age (12th century BCE) Philistines in Tel Erani in the southern Levant. Another wave of introductions later spread bananas to other parts of tropical Asia, particularly Indochina and the Indian subcontinent. However, there is evidence that bananas were known to the Indus Valley civilisation from phytoliths recovered from the Kot Diji archaeological site in Pakistan (although they are absent in other contemporary sites in South Asia). This may be a possible indication of very early dispersal of bananas by Austronesian traders by sea from as early as 2000 BCE. But this is still putative, as they may have come from local wild Musa species used for fiber or as ornamentals, not food. Southeast Asia remains the region of primary diversity of the banana. Areas of secondary diversity are found in Africa, indicating a long history of banana cultivation in these regions. The banana may also have been present in isolated locations elsewhere in the Middle East on the eve of Islam. The spread of Islam was followed by far-reaching diffusion. There are numerous references to it in Islamic texts (such as poems