From Forests to the Coast - Multidisciplinary Investigation of Human Adaptations at the Mini-athiliya Shell Midden, Sri Lanka

Abstract

Over the last three decades, Sri Lanka has risen to international prominence as a key area for exploring past forager adaptations. Much of this discussion has focused on the lowland rainforests of the Wet Zone of the island, and their preservation of the earliest fossils of our species, bone tools, and microlithic technologies in the region ca. 45,000 years ago. It has been recognized that the northern and southern coasts of Sri Lanka represent crucial locales for studying human occupation and adaptation through the Pleistocene and Holocene. Here, we revisit the important shell midden site of Mini-athiliya (dating to ca. 4,000 cal. years BP), on the southern coast of Sri Lanka, which has yielded human remains alongside microlithic stone tools and animal remains. We present a comparative analysis of body size variation of the human remains belonging to the HMA 6 adult skeleton from Mini-athiliya with a wider database of foragers to investigate local adaptations. We also apply stable carbon and oxygen isotope analysis to the tooth enamel of four other individuals documented at Mini-athiliya in order to determine their dietary reliance on forest, grassland, or coastal resources. Together, our results highlight that, rather than a clear distinction between earlier forest adaptations and later coastal specialisation, the Mini-athiliya individuals provide evidence for a plastic spectrum of ecological adaptation. We argue for continued research on  how human populations in different parts of the island interacted and adapted to its diverse tropical settings across space and time.