Riverine, Biological and Cultural Evolution in Southeastern Australia
Pardoe, Colin, Antiquity
The rise of cemeteries, extreme biological diversification, size decrease, increased violence, disappearance of megafauna, exploitation of different resources, evolution of rivers to an expanded system of microenvironments, changes in occupation. How are these features of Australian Aboriginal societies in the great river-systems of the southeast related@ From evidence of geomorphology, skeletal biology and other aspects of the archaeological record, a sharp disjunction between two different and relatively stable states is seen: a transforming transition rather than a gradual change.
In a general model for a transition of territoriality, society and biology set against the evolution of river systems of the Murray Darling Basin, I pursue the interaction of ecology, society and biology in a rough chronological framework within the volume's theme. While there is good evidence for a convulsive transition in many facets of Aboriginal society (a punctuated equilibrium model), this transition had its beginnings after the Glacial Maximum with greatest effects (i.e., archaeological visibility) near the Altithermal; about 7000 b.p.
Transitions presuppose change. We see change everywhere around us, since variation, diversity and change characterize the geological and biological world. To discuss transitions, we have to take the long-term view so that we may point to a time unit when changes are greater than normal. And this is the crux: what do we measure in order to infer a transition rather than a gradual change from one characterization of the archaeological record to another?
This paper is not about causal agency. It is about a metric for change. Alongside changes to the physical world, what changes are observed in the archaeological record? Do they warrant the notion of a transition for Aboriginal people living thousands of years ago? Significant environmental changes occured over the last 18,000 years, but the Altithermal period, around 7000 years ago, marks a punctuation in Aboriginal demographic, social and biological organization rather than a gradual process of social change.
The Murray and Darling river systems flow through a semi-arid plain in which water availability varies through the year, in longer-term cycles of drought, and in the longest-term cycles of world glaciation. Rivers are a focus of occupation for their water, and for the food and other resources they concentrate. All the Murray - Darling's flow comes from the headwaters, and the contrast between the narrow corridor along the river and the surrounding arid country is extreme. This is why the rivers are central to the human history of the Basin, where for thousands of years large numbers of people have been packed in groups of relatively high density along the waterways. Today in western New South Wales Aboriginal people's names for themselves often translate as the people of the river'.
So I start with the transformation of rivers.
The Murray - Darling Basin (Figure 1) extends from the eastern edge of the Great Dividing Range, across the plains of central and western New South Wales, down through South Australia to the southern coast: 1,036,000 sq. km, something over one-seventh of the continent. The River Murray Basin itself is about 300,000 sq. km. The main rivers today in their long, sinuous courses (the Murray 2570 km, the Darling 2730 km), are exotic interlopers, for they are fed mainly from their headwaters on the western slopes of the Dividing Range to the east. In much of the region, evaporation greatly exceeds rainfall.
The contemporary Murray Basin may be typified as six regions. The headwaters of the Dividing Range are the main catchment. In the eastern riverine plain, 500 x 300 km, the main streams of the catchment (Lachlan, Murrum-bidgee, Murray) wend across a plain of extremely low gradient, averaging 20 cm/km, and at the western edge of the plain join together. …