Horticultural Experimentation in Northern Australia Reconsidered
Denham, Tim, Donohue, Mark, Booth, Sara, Antiquity
In 1770, Joseph Banks portrayed Aborigines living along the Queensland coast as being 'ignorant of the arts of cultivation' (Beaglehole 1962: 123). Since that time, prehistorians working inside and outside Australia have persistently restated its unique character as a 'continent of hunter-gatherers' (e.g. Lourandos 1997; Bellwood 2005; cf. Barker 2006: 227-8). An assessment of multi-disciplinary data from northern Australia, primarily botany and geomorphology, challenges this view. Rather than locking Aboriginal Australians into a relatively timeless and static historical template (David & Denham 2006), the available data for northern Australia suggests that there were major cultural transformations during the Holocene, structured by environmental and social contingencies. This dynamic history requires consideration of mid- or late Holocene interaction between Australia and New Guinea, and potentially Island Southeast Asia, and resurrects a hypothesis proposed by Jones and Meehan (1989) for the earlier existence of an 'experimental horticultural province' in northern Australia before sea levels rose to form the Torres Strait during the early Holocene:
"It is possible that the first experimental cultivation of such plants as Colocasia and possibly yams, bananas, sugar cane, and Pandanus, took place at th[e] time when New Guinea and Australia were part of the same landmass. The southern boundary of this experimental horticultural province may have been on what is now Australia' (Jones & Meehan 1989: 132).
The three important cultivated domesticates in New Guinea that are minor 'wild' food plants in northern Australia ate the banana (Musa acuminata ssp. banksii), taro (Colocasia esculenta) and the greater yam (Dioscorea alata). In this paper, we begin with a consideration of the changing geography of northern Australia since the Terminal Pleistocene, in order to characterise the environmental context for human and botanical processes. Following this, we review the botanical and historical records for these three food plants in Australia. Although many details remain to be elicited, the histories of these food plants require us to reconsider depictions of Australia as always having been a 'continent of hunter-gatherers'.
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Sea levels, landmasses and social interaction
Figure 1 shows the geometry of the coastline of northern Sahul before and immediately after the severing of the land bridge (after Lambeck & Chappell 2001; Chappell 2005). The flooding of the region north and west of Arnhem Land to form the Arafura Sea and Gulf of Carpentaria, respectively, occurred in the Terminal Pleistocene (c. 12 000 years ago). From this time, communities in present-day Arnhem Land became increasingly isolated from their former neighbours living to the north, as did communities living on Cape York and the present-day islands of the Torres Strait from approximately 8500 years ago following the flooding of the land bridge between Australia and New Guinea. Maritime interaction occurred within and across the Torres Strait from at least c. 2500 years ago (McNiven et al. 2006).
Approximately 6000 years ago, much of the southern coast of New Guinea was further north than today (Figure 1). Coastal progradation has extended the coastline southward during the last several thousand years; it was fed by deposition from several major river systems draining the highland spine of New Guinea (Swadling & Hope 1992). As well as being further north, much of the low-lying coastline at this time would have been subject to periodic and major flooding. Consequently, there are strong environmental factors disrupting regional social continuity between northern Australia, islands of the Torres Strait and southern New Guinea.
Plant distributions and human agency
Bean (2007: 4-6) has argued that botanists have often overlooked or underestimated the role of human agency in the dispersal of floral species and concludes that a range of plants formerly thought to be indigenous have been introduced by people to Australia in the recent and distant past. …