title: Holocene Demographic Changes and the Emergence of Complex Societies in Prehistoric Australia.
abstract: A continental-scale model of Holocene Australian hunter-gatherer demography and mobility is generated using radiocarbon data and geospatial techniques. Results show a delayed expansion and settlement of much of Australia following the termination of the late Pleistocene until after 9,000 years ago (or 9ka). The onset of the Holocene climatic optimum (9-6ka) coincides with rapid expansion, growth and establishment of regional populations across ~75% of Australia, including much of the arid zone. This diffusion from isolated Pleistocene refugia provides a mechanism for the synchronous spread of pan-continental archaeological and linguistic attributes at this time (e.g. Pama-Nyungan language, Panaramitee art style, backed artefacts). We argue longer patch residence times were possible at the end of the optimum, resulting in a shift to more sedentary lifestyles and establishment of low-level food production in some parts of the continent. The onset of El Niño - Southern Oscillation (ENSO; 4.5-2ka) restricted low-level food production, and resulted in population fragmentation, abandonment of marginal areas, and reduction in ranging territory of ~26%. Importantly, climate amelioration brought about by more pervasive La Niña conditions (post-2ka), resulted in an intensification of the mobility strategies and technological innovations that were developed in the early- to mid-Holocene. These changes resulted in population expansion and utilization of the entire continent. We propose that it was under these demographically packed conditions that the complex social and religious societies observed at colonial contact were formed.
authors.affiliation: Fenner School of Environment and Society, The Australian National University, Canberra, Australia; Archaeological & Heritage Management Solutions Pty Ltd, Waterloo, Australia.
authors.forename: Alan N
authors.initials: AN
authors.lastname: Williams
authors.affiliation: College of Arts, Society and Education, James Cook University, Cairns, Australia.
authors.forename: Sean
authors.initials: S
authors.lastname: Ulm
authors.affiliation: Climate Change Research Centre and School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, Australia.
authors.forename: Chris S M
authors.initials: CS
authors.lastname: Turney
authors.affiliation: School of Geography, Planning and Environmental Management, The University of Queensland, Brisbane, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Rohde
authors.affiliation: Science and Engineering Faculty, Queensland University of Technology, Brisbane, Australia.
authors.forename: Gentry
authors.initials: G
authors.lastname: White
mesh_terms: D001106:Archaeology; D066046:Diet, Paleolithic; D059000:El Nino-Southern Oscillation; D005580:Fossils; D006801:Humans; D011157:Population Dynamics / Q000706:statistics & numerical data*