Late Pleistocene human paleoecology in the highland savanna ecosystem of mainland Southeast Asia

The late Pleistocene settlement of highland settings in mainland Southeast Asia by Homo sapiens has challenged our species's ability to occupy mountainous landscapes that acted as physical barriers to the expansion into lower-latitude Sunda islands during sea-level lowstands. Tham Lod Rockshelter in highland Pang Mapha (northwestern Thailand), dated between 34,000 and 12,000 years ago, has yielded evidence of Hoabinhian lithic assemblages and natural resource use by hunter-gatherer societies. To understand the process of early settlements of highland areas, we measured stable carbon and oxygen isotope compositions of Tham Lod human and faunal tooth enamel. Our assessment of the stable carbon isotope results suggests long-term opportunistic behavior among hunter-gatherers in foraging on a variety of food items in a mosaic environment and/or inhabiting an open forest edge during the terminal Pleistocene. This study reinforces the higher-latitude and -altitude extension of a forest-grassland mosaic ecosystem or savanna corridor (farther north into northwestern Thailand), which facilitated the dispersal of hunter-gatherers across mountainous areas and possibly allowed for consistency in a human subsistence strategy and Hoabinhian technology in the highlands of mainland Southeast Asia over a 20,000-year span near the end of the Pleistocene.

Automated summary

This study examines the settlement of highland areas in mainland Southeast Asia during the late Pleistocene, focusing on the Tham Lod Rockshelter in northwestern Thailand. Analysis of stable carbon isotope results suggests long-term opportunistic behavior among hunter-gatherers in foraging on a variety of food items in a mosaic environment. The study reinforces the extension of a forest-grassland mosaic ecosystem or savanna corridor farther north into northwestern Thailand, facilitating the dispersal of hunter-gatherers across mountainous areas and potentially allowing for consistency in human subsistence strategy and technology over a 20,000-year span near the end of the Pleistocene.