A new population curve for prehistoric Australia

Abstract

This paper presents a new reconstruction of prehistoric population of Australia for the last 50 ka, using the most comprehensive radiocarbon database currently available for the continent. The application of new techniques to manipulate radiocarbon data (including correction for taphonomic bias), gives greater reliability to the reconstructed population curve. This shows low populations through the Late Pleistocene, before a slow stepwise increase in population beginning during the Holocene transition (approx. 12 ka) and continuing in pulses (approx. 8.3-6.6, 4.4-3.7 and 1.6-0.4 ka) through the Holocene. These data give no support for an early saturation of the continent, although the estimated population following initial landfall was probably greater than previously allowed (comparable with the Early Holocene). The greatest increase in population occurred in the Late Holocene, but in contrast to existing intensification models, changes in demography and diversification of economic activities began much earlier. Some demographic changes appear to be in response to major climatic events, most notably during the last glacial maximum, where the curve suggests that population fell by about 60 per cent between 21 and 18 ka. An application of statistical demographic methods to Australian ethnographic and genetic data suggests that a founding group of 1000-2000 at 50 ka would result in a population high of approximately 1.2 million at approximately 0.5 ka. Data suggests an 8 per cent decline to approximately 770 000-1.1 million at the time of European contact, giving a figure consistent with ethnographic estimates and with historical observations of the impact of smallpox, and other diseases introduced by Macassans and Europeans during and after AD 1788.

Human population dynamics in Europe over the Last Glacial Maximum

“…To further evaluate the ability of climate envelope modeling approach to correctly simulate hunter-gatherer populations, we simulated Australian hunter-gatherer population at 0.5 ky ago and compared the result to the historical, ethnographic, and archaeological estimates of population size at the European contact (64)(65)(66). This simulation is presented in the supplement (SI Text and Fig.…”

On Vastness and Variability: Cultural Transmission, Historicity, and the Paleoindian Record in Eastern South America

“…Even if it is not, is there any reason to suppose that the first people to colonize the Americas would show a growth rate that is two to three times higher than the one observed for extant hunter-gatherers? A recent simulation for the population growth of Australian hunter-gatherers, taking into account the radiocarbon ages, points to much lower rates, ranging between 0.09% and minus 0.05%, with an average of 0.01% (Williams 2013).…”

Climate, not Aboriginal landscape burning, controlled the historical demography and distribution of fire-sensitive conifer populations across Australia

“…Under the hypothesis that climate had a major role in Callitris distribution change, it can be expected that the distribution ranges in the arid zone would have contracted or even retreated to coastal regions because of desertification under decreased rainfall during the LGM [32,33]. On the other hand, the humancaused burning hypothesis predicts that, since human arrival, the fire-prone Callitris populations would have collapsed most severely in the monsoon tropics, where grassy fuels and human activity were the highest [9]. In this study, the alternative hypotheses are tested based on three approaches: reconstruction of palaeodistributions using species distribution modelling; phylogeographic analysis of relationships among regional populations and explicit modelling of historical demography of populations based on genetic data.…”

“…Indeed, burning is postulated as the key driver of the mass extinction of megafauna in Australia around 45-50 kya through altering vegetation to fire-adapted plant communities [8]. On the other hand, there is a lack of congruence between human activity and fire records during 20-40 kya, a period of consistently low Aboriginal populations [9] and large changes in fire regimes [10], and recent studies argue for significant roles of climate change on vegetation shift and megafauna extinction [11][12][13][14]. Furthermore, studies of sedimentary records from the humid tropics and southeastern Australia suggest an ecological feedback, where relaxed herbivore pressure following extinction of megaherbivores resulted in a switch to flammable sclerophyllous vegetation, which increased fire activity [15,16].…”