Why negritos (and hunter-gatherers in general) should be found so close to
farmers even in earlier times, when forestland was more abundant, has been much
debated and has generated the controversial proposition that it is because tropical
rainforests are poor in carbohydrates: “Wild starch foods, and especially wild yams,
may be too scarce in such biomes to sustain independent hunter-gatherers without
recourse to cultivated foods” (Headland 1987: 464). Respondents have largely
refuted this: among other reasons, the “wild yam hypothesis” does not take into account
the heterogeneity and diversity of the rainforests, or hunter-gatherer agency in
managing their so-called wild resources (Bahuchet 1992; Brosius 1991; Colinvaux
and Bush 1991; Endicott and Bellwood 1991). Ethnographers and archaeologists
have commonly described forager-farmer relationships as “symbiotic” (Endicott
1984; Headland and Reid 1989; Hutterer 1988). The symbiotic model assumes
divergent specialization, with foragers and farmers inhabiting complementary
niches. At its simplest, the model describes proteins from the forest flowing out
and carbohydrate staples from the fields flowing back in. Thus, each provides what
the other lacks, and both benefit (Spielmann and Eder 1994).