Human paleodiet in tropical Southeast Asia: Isotopic evidence from Niah Cave and Gua Cha

Prehistoric human diet is explored using skeletal material from late Pleistocene-Holocene archaeological sites in Malaysia. Studies of past subsistence in the Southeast Asian tropics have been few, in part due to poor preservation of organics. To circumvent this problem, stable carbon (δ 13C) and oxygen (δ18O) isotope ratios were determined using tooth enamel apatite, a biogenic mineral less prone to diagenesis than bone collagen or bone apatite. These methods are well established in paleodietary studies, and allow quantitative correlation between diet and consumer tissues.;Primary study sites include Niah Cave, in northern Borneo (Sarawak), with extensive late Pleistocene-Holocene deposits at its West Mouth, and Gua Cha, on the Malay Peninsula (Kelantan), a rock shelter with Holocene deposits. Both sites are situated in C3-dominant rain forest and contain pre-Neolithic and Neolithic human remains and the remains of human activity. Ancillary data from two Neolithic/Early Metal sites in Sarawak, Gua Sireh and Lubang Angin, provide broader comparison.;Human δ13C results exhibit a broad range of values between −15.7 and −11.3‰, consistent with a C3-based subsistence regime. Pre-Neolithic samples are significantly more negative on average (δ13C = −14.5‰) than their Neolithic counterparts (δ13C = −13.2‰). Gua Sireh individuals concord with the Neolithic samples; Lubang Angin with the pre-Neolithic.;More negative δ13C values suggest closed canopy foraging. Research on the canopy effect phenomenon of closed forest habitats, documenting a gradient of increasingly negative δ13C values in leaves from top canopy to forest floor, support this interpretation. Collectively, more positive δ13C values suggest increased consumption of C3 plant foods obtained from open habitats. Isotopic analysis of faunal remains from Niah Cave and of modern plant foods from Sarawak are consistent with these findings.;Results show that δ13C values can be retrieved intact from tooth enamel apatite and may serve as a proxy for open forest horticulture when other influences (e.g., C4 plants, marine foods) are ruled out. Pre-Neolithic human foraging patterns in tropical Southeast Asia were distinctly different from those of the Neolithic and data provide a useful test for assessing rain forest habitation independent of or prior to the development/adoption of agriculture.