Human behavioural dynamics in island rainforests: evidence from the Raja Ampat Islands, West Papua

Abstract

During the Late Pleistocene and Holocene (over the past c. 100,000 years), Homo sapiens dispersed into a wide array of novel, challenging environments. Remarkable adaptive flexibility encouraged humans to improvise social and technical behaviours, while niche constructing tendencies enabled them to reshape their ecologies. However, the rate and scale at which humans could transform their behaviours and environments in the deep past remains unclear. This thesis explores how humans came to frequent one particularly challenging environment — small-island rainforests — for the first time. The research examines the peopling of Wallacea and the circum-New Guinea Islands, with new evidence from the Raja Ampat Islands, which lie at the interface of these two biogeographic regions known as Lydekker’s Line. The thesis first introduces adaptive flexibility and niche construction theory, plus provides an overview of the Raja Ampat Archaeological Project. It critically analyses literature on the ecological implications of islands and tropical forests for human occupation, and emphasises how these environments fluctuate through time and stimulate behavioural flexibility. It then provides a novel reappraisal of the linguistic, genetic, and archaeological evidence for human dispersals through Wallacea and New Guinea, as different human populations passed back and forth across a major biogeographic line. Next, it examines how settlement behaviours have changed in the northern Raja Ampats, particularly in the recent past, drawing on historical and ethnographic evidence; it also examines how site distributions are patterned, building on original site reconnaissance survey. Chronostratigraphic and palaeoecological data from new cave excavations in the northern Raja Ampats are presented to examine how their use has fluctuated across c. 50,000 years of occupation, alongside environmental changes including marine transgressions and shifting forest cover. This is followed by exploration of how foraging practices transformed through the millennia, drawing principally upon zooarchaeological analyses. How people’s technological behaviours changed through time is then addressed primarily through bone tool, lithic, and ceramic analyses, particularly during the Holocene. A synthesis of the new evidence discusses how it can be understood within the regional context of Wallacea and New Guinea, and in a global comparative framework. A conclusion highlights the contribution made to understanding how humans transformed their behaviours and the insular forest ecologies they inhabited, and considers how we can model the temporal dynamics of human behaviour over the longue durée.