Asian Crop Dispersal in Africa and Late Holocene Human Adaptation to Tropical Environments

Abstract

Occupation of the humid tropics by Late Holocene food producers depended on the use of vegetative agricultural systems. A small number of vegetative crops from the Americas and Asia have come to dominate tropical agriculture globally in these warm and humid environments, due to their ability to provide reliable food output with low labour inputs, as well as their suitability to these environments. The prehistoric arrival in Africa of Southeast Asian crops, in particular banana, taro and greater yam but also sugar cane and others, is commonly regarded as one of the most important examples of transcontinental exchanges in the tropics. Although chronologies of food-producer expansions in Central Africa are increasingly gaining resolution, we have very little evidence for the agricultural systems used in this region. Researchers have recovered just a handful of examples of archaeobotanical banana, taro and sugar cane remains, and so far none from greater yam. Many of the suggested dispersal routes have not been tested with chronological, ecological and linguistic evidence of food producers. While the impact of Bantu-speaking people has been emphasised, the role of non-Bantu farmers speaking Ubangi and Central Sudanic languages who have expanded from the (north)east has hardly been considered. This article will review the current hypotheses on dispersal routes and suggest that transmissions via Northeast Africa should become a new focus of research on the origins of Asian vegeculture crops in Africa.

Chromosome evolution and the genetic basis of agronomically important traits in greater yam

“…Greater yam ( Dioscorea alata L.), also called water yam, winged yam, or ube, among other names, is the species with the broadest global distribution 1 . D. alata is thought to have originated in Southeast Asia and/or Melanesia 2,6 . It was introduced to East Africa as many as 2,000 years ago and reached West Africa by the 1500s 2,7 .…”

Exotic foods reveal contact between South Asia and the Near East during the second millennium BCE

“…Banana fruit is highly perishable and domesticated bananas are seedless (reproducing instead by cuttings), and thus there is a strong bias against the recovery of banana macrobotanical remains. Phytoliths represent the principle method employed to trace early banana use, but banana phytolith recovery from archaeological contexts is generally low, perhaps due to the limited number of phytoliths produced by the plant, the lack of phytoliths in the consumed mesocarp, and other taphonomic factors (112,113). Direct evidence of banana, in the form of phytoliths, has been found at three Indus sites dating to the late third millennium (114)(115)(116)(117), placing the crop in South Asia by that date.…”

Looking beyond history: tracing the dispersal of the Malaysian complex of crops to Africa

“…Subsequently, they were spread by farmers across the continent (De Langhe, 2007). The archaeobotany of introduction for vegetatively propagated crops to Africa, like anywhere else, is poorly documented and taxonomically imprecise or debatable (Neumann and Hildebrand, 2009; Power et al, 2019; Denham et al, 2020).…”

“…If the extent of adoption is taken as a guide to time depth, then bananas, sugarcane, taro, and yams were seemingly introduced earlier than the other Malaysian crops because they were incorporated into nascent farming systems across equatorial Africa. The timing of these introductions has been suggested at around 2500–3000 years ago, during the formation and expansion of Bantu cultivation practices in West and Central Africa (Dalziel, 1955; Blench, 2007; Rangan et al, 2015; Power et al, 2019). If this interpretation is correct, these crops were introduced under vegetative forms of cultivation because they are cultivated through clonal propagation, presumably along the African eastern or northern coasts, more than 3000 years ago.…”