diverse theoretical and methodological approaches. In this section we examine four questions that have generated the most research.
Subsistence and settlement
Can forest foragers live in the tropical forest without exchanging carbohydrates with farmers?
Bailey et al. (1989, 60) proposed the controversial hypothesis that “humans have never lived in tropical rain forest independently of domesticated plants and animals.” In light of the ubiquity of forager-farmer exchange observed throughout the region in modern times, it is reasonable to question whether a hunting and gathering subsistence system is possible in this context without access to domesticated foods (Bailey and Headland 1991; Headland and Bailey 1991). Headland (1987) argues that the natural availability of carbohydrate-rich resources, such as wild yams, is a critical limiting factor in rain forest subsistence. As a result, the issue of whether foragers lived independently in the rain forest prior to the arrival of Bantu farmers and their cultivated calories is referred to as the “wild yam question.” Ethnoecological data centering on the environmental distribution of wild yams have been collected by French and Japanese anthropologists to explore contexts in which contemporary forest foraging is possible, and to extrapolate prehistoric possibilities (Bahuchet et al. 1991; Dounias 2001b; Hladik and Dounias 1993; Sato 2001; Yasuoka 2006b, 2009). The most direct challenge to the cultivated calories hypothesis comes from archaeology. As more archaeological evidence is unearthed, it increasingly supports rain forest occupation by hunter-gatherers long before the arrival of farmers (Barham and Mitchell 2008), and possibly beyond 200,000 years ago (Mercader 2002, 2003). Nevertheless, as Bailey et al. (1989) hoped, the wild yam question has proven very successful at stimulating ecological and archaeological research in the Congo Basin.