Australia: The Land Where Time Began
Aboriginal Occupation of south central Tasmania in the Pleistocene - Palaeoecology
The populations of the Australian Aboriginal people in the Pleistocene have been characterised as being low density and widespread, with little variation between regions over large areas of the continent (White & O'Connell, 1982). The nature of the archaeological evidence, being geographically diverse and in most cases no more than a few material remains being found, tended to at least partially support these assumptions. According to the authors contemporary demographic models (1998) suggest a narrow resource base as being used by Aboriginal populations in the Pleistocene, the groups were highly mobile, with the result that site occupation appeared to be ephemeral, which was reflected in the archaeological record. In a social context these groups are characterised as egalitarian, with less complex social networks that was the case in the mid-Holocene (Lourandos, 1983: 88; 1985: 398). According to this a trajectory exists of socio-economic complexity from foragers (Pleistocene) to collectors (mid-Holocene) (Lourandos, 1987: 158).
The authors suggest that hunter-gatherer socio-economic organisation and change are inevitably unidirectional in such notions where different behaviours over enormous lengths of time-scales have been blended, promoting ideas of modal behaviours though denying the existence of alternative behaviours that are systematic on a regional scale, and possess inherent variability. The authors agree with the statement 'by equating foraging behaviour with egalitarian sociopolitical relationships, by merging the means of the two, we eliminate the range of variability present in each construct' (Soffer, 1987: 492). They say that the range of variability associated with modern humans is greater than has been realised previously. Evidence has been found that there is not a 1-to-1 correlation between the advent of modern Homo sapiens and any particular classes of stone tools (Trinkhaus, 1986; Foley, 1987). It has been pointed out that, though the first people to arrive in Australia were essentially modern humans, the morphology and technology of their stone artefacts 'could come out of the African or European Lower Palaeolithic (Gowlett, 1987: 215), a pattern that had been recognised by early researchers (Jones, 1977: 190-1; White, 1977: 24). Observation that early Aboriginal colonists must have had an efficient marine technology prior to 40,000 BP [60,000 BP suggested by dating in NW Australia] to be able to cross the ocean gaps between the nearest island and the mainland of Greater Australia, thus extending the contrast (Jones, 1987), as well as possessing an artistic tradition that was probably older than 30,000 years (Dorn et al., 1988; Nobbs, 1988). Direct implications for ideas of unidirectional trajectories result from these paradoxes, based on value-laden archaeological data sets and assumptions employed to explain changes of human behaviour.
The Tasmanian Aborigines have provided models for reconstructing human behaviour during the Pleistocene for more than 100 years, because of their isolation in the Holocene and their geographical position that is unique (e.g. Sollas, 1911: 70). The authors say the practice has continued, in spite of good reasons to question the practice, one of the main reasons being the actual nature of human behaviour in Tasmania during the Pleistocene. Southeast Tasmania during the Holocene has been seen as a regional exemplar of what is likely to have been indicative of the character of the behaviour of Aboriginal populations during the Pleistocene, suggesting that the Kutikina Cave site (Liernan et al., 1983) in southwest Tasmania, of Pleistocene age, represents inland hunting, that is transient, is indicative of Aboriginal behaviour in the Pleistocene (Lourandos, 1985: 397).
There would be not much variation in the archaeological record between the 2 regions if this was actually the case. The actual situation as seen from more recent excavations in southeast and southwest Tasmania has demonstrated a degree of archaeological richness and variation not previously reported for any other part of Australia from the Pleistocene (Goede & Murray, 1977; Goode et al., 1978; Murray & Goode, 1980; Jones, 1984; Kiernan et al., 1983; Blain et al., 1982; Jones & Allen, 1984; Jones et al., 1988; Allen et al., 1988; Cosgrove, 1989; Cosgrove & Jones, 1989; Allen, 1989; Allen & Cosgrove, 1989; Allen et al., 1989). 41 sites, both cave and open sites, have been reported from these areas indicating that occupation of these zones was continuous from 30,000 BP to 11,000 BP. Of the more than 20 radiocarbon dates that had been reported the eastern portion of Tasmania prior to 1987 all were 10,000 BP or younger. The Southern Forests Archaeological Project was initiated in 1987, with the specific aim of investigation the temporal paradox, as well as investigating, elaborating and verifying propositions resulting from previous research, especially at Kutikina Cave.
It has been found that the periglacial upland areas of Tasmania were settled by humans in the Late Pleistocene, at least 30,000 BP, 10,000 years earlier than had previously been believed to have occurred, from western valleys in the southwest, based on preliminary investigations of archaeological sites in south central Tasmania. Findings and conclusions that had been advanced for the Nunamira Cave site and the ORS 7 site have been supported by findings from 2 sequences, Bone Cave and M86/2 site. Rich faunal assemblages of large bones that are identifiable, Stone tools that are distinctive, and stone raw materials that are location specific, allow the sites from southwestern Tasmania dating to the Pleistocene to be distinguished fro other Pleistocene regions of Australia. According to the authors, the eastern zone can be distinguished from the western zone in the archaeological signatures within the Pleistocene province. An archaeological basis has been established for examining the associations between sites within the province as well as across its boundaries.
The study site in south central Tasmania is at the division of 2 environmental zones in southern Tasmania, a fold-structured geology with a vegetation of temperate rainforest to the west, and to the east, a fault-structured geology with a vegetation cover of dry sclerophyll forest (Kirkpatrick, 1982) (Fig. 6a.1). The location is a central pivot from which the variability of southeast and southwest Tasmania can be compared and contrasted. A palaeoecological conceptual framework has been used because ethnographic or archaeological analogues for the Tasmanian deposits are unknown in the rest of Australia. Their conceptual framework was generated from earlier archaeological data, as well as information on soils, vegetation and animal ecology. The authors hope they will be able to observe links and relationships between the archaeological record, that is static, and human behaviours that produced them, that are dynamic, by understanding some ecological aspects of the zone that were present during the Pleistocene.
The model proposed by the authors suggests that at any one time in the Pleistocene the ecological make-up of the southwest region of Tasmania provided an animal resource that was relatively sedentary and that was potentially concentrated. This appears to be suggested by the presence of high concentrations of smashed bones, derived mostly from a single species, the red-necked wallaby, in all sites that have been excavated. According to the authors, it is important that a juxtaposed mosaic of ecotones is predicted for the region by their model, a general expectation of a high level of species richness and diversity (Wiens, 1985: 184; King & Graham, 1981), especially in patches of grassy microenvironments that are well watered are surrounded by scrub and low lying trees. The authors suggest there could be an expectation that part of the range of habitats in the region would have been exploited by humans in the Pleistocene, and that some evidence of this would be found in the excavated sites, in the form of the remains of a number of species of animal. The only sites where this has been found to be the case, though to a lesser extent than expected, the systematically exploited species numbers being low, were at Nunamira Cave, Bone Cave and M86/2. An example is the low level exploitation of the emu at Nunamira Cave, where there doesn't appear to be a necessary correlation between the resources forming the subsistence base and the range of the available resources that are predicted.
The seasonal presence of humans in at least 1 site, that corresponds to the most stressful part of the year, late winter and early spring, is suggested by the presence of emu eggshell. It has been found that the diets of hunter-gatherers living at high latitudes, temperate, subarctic and arctic zones, become marginal and inadequate in late winter and early spring, especially when they rely on lean meat for energy (Speth & Spielman, 1983). At this time the physical condition of humans, as well as other animals, is reduced, as a result of higher metabolic rates, higher calorific requirements and a fatty acid deficit, especially in environments that are sharply seasonal (Speth & Spielman, 1983: 2). Reliance on a high protein diet, at a time when food plants are not available, can be detrimental to the physiology of hunter-gatherers (Speth, 1987; Noli & Avery, 1988).
The meat of kangaroos and wallabies is extremely lean and the fat deposits around the kidneys, as well as in the marrow and on the back and tail are limited (Sinclair, 1988; O'Dea, 1988). In female red-necked wallabies it has been found that in winter there is a significant drop in the kidney fat, the same effect being found in wallabies living in dry zones compared to those living in wetter zones (Driessen, 1988: 16). Towards the end of winter the males put on condition, presumably in preparation for the mating season (Driessen, pers. com to Cosgrove et al.). It has also been suggested by field studies that pasture quality was a factor in the deposition of kidney fat. Wallabies living in high rainfall areas, on ranges that are more fertile, appear less stressed and have a physical condition that is enhanced, according to the available evidence. In areas with lower rainfall the females have fewer young at foot than those from wetter areas (Driessen, 1988: 23). In west Tasmania during the Late Pleistocene, the moister habitats of the region have been suggested by the authors to possibly been crucial in the aggregation of animals in the southwest, as well as to the health of the animals.
Macropod meat has been found to have the potential to dilate blood vessels and increase blood flow in response to cold. Experiments with humans, in which the subjects ate kangaroo meat, found that blood levels of arachidonic acid were increased (O'Dea, 1988). It is believed that this acid 'modulates the thrombosis tendency by affecting the platelet aggregation and blood flow' (O'Dea, 1988: 42). The opposite effect was found in subjects eating lean southern fish, these subjects had reduced blood flow in response to cold. See Rocky Cape Food* It has been suggested by O'Dea that the presence in the blood of such long chain fatty acids (PUFA) may protect against thrombosis. It is not known if the Aboriginal population of Pleistocene Tasmania had metabolic rates that were inherently higher, as has been found at the present in Eskimo (Inuit) and Patagonian populations (Kirk, 1983: 158). This suggests it might have been advantageous for the Aboriginal population of glacial Tasmania to have had PUFA in their blood.
*Could this explain the absence of fish bones from Tasmania deposits after about 3,500 BP? This is of necessity purely speculative as I have not seen it mentioned in Sources 1 or elsewhere, based entirely on the studies of the eating of kangaroo meat and Tasmanian coldwater fish. I would be interested to know if this has been suggested as a reason for the removal of fish from the diet, or even if it is considered a possibly reason. The disappearance of fish bones from the deposits at Tasmanian occupation sites occurred long after the close of the glacial period, but even at the present the winters in Tasmania, especially in some parts, are cold, wet and windy, especially for a people with a minimum of protection from the weather, as was reported of the Tasmanian Aboriginal people at the time of first contact.
In the subantarctic environment that existed in Tasmania during the glacial phase the diet of lean meat would not provide all essential nutrients in late winter and early spring seasonal fluctuations, with the absence of plant carbohydrates. It has been suggested (Bowdler, 1981, 104) that the small daisy yam, Microseris scapigera, may have been present in glacial Tasmania, as it presently grows in subalpine grasslands of Tasmania (Jackson, 1973: 71), though no evidence has been found in any of the sites of the use of plants.
The possibility of protein poisoning would be increased by the lack of animal fats and carbohydrates (Noli & Avery, 1988: 396). The intensive processing and extraction of marrow (see Fauna) has been suggested as a possible solution to this potential problem, bone marrow containing the essential fatty acids such as linoleic acid, that is used in protein metabolism, the fats and carbohydrates enhance the effects of protein-sparing (Speth & Speilman, 1983: 13).
In the sites that have been excavated some body parts of macropods are well represented and were systematically broken in the sites. These bones, wallaby tibia, femurs, metatarsals and humeri, the bones that in ungulates, as well as kangaroos, contain relatively high levels of marrow (Binford, 1978: 152, 188; 1981: 150; O'Connell & Marshall, 1989; Jones & Metcalf, 1988). It has been suggested that at high risk times of year they might allow the bridging of the dietary gap between winter and summer. According to the authors it is not certain why there was preferential selection of the red-necked wallaby as the main prey species, as other larger species, such as the wombat, the pademelon, the emu and the grey kangaroo, that was much larger, all of which are species inhabiting the grasslands in the river valleys at the time, in particular the Florentine Valley, remains of such species being found in caves and limestone pitfalls. All these animals have long bones that would have made a good addition to those of the red-necked wallaby that was the predominant prey species. It has been suggested that the improved physical condition of the male red-necked wallabies feeding on better-watered pasture towards the end of winter may have been a key factor in the exploitation of this species. It has also been suggested that the unpredictable, nomadic behaviours of the larger animals, together with their larger ranges and their smaller group make-up, may have contributed to reduced hunting success (Horton, 1981: 23). The red-necked wallaby would seem to have been an attractive prey species, based on these criteria, being a more attractive investment of time and labour, as the hunting success with this species would probably have been consistent and predictable throughout the year, though it is not known if the animal composition and abundance was different during the Late Pleistocene.
According to the authors it is difficult to assess palaeo-diets, even with well preserved food refuse in middens and the use of stable carbon isotope analysis of any human collagen that is present (Collier & Hobson, 1987). Study of the middens doesn't reveal the total and exact diet of the occupants of a site, only giving an indication of the foods eaten over long periods of time, and is not believed to give a complete picture of the economic strategy. Stable carbon isotope analysis of the collagen indicates the diet at a specific location. It has been suggested that wallabies may have performed the role of a food source that was relatively sedentary, tiding the people over stressful periods, such as the glacial winters, when food could be scarce, the dependence on wallabies being suggested as a glacial, middle-latitude animal correlate of 'low-key dependable vegetable resources' (Bowdler, 1981, 100). The authors warn of the risk of overemphasising a diet of terrestrial animals, not recognising the role of marine and plant food in the diet, the role of these foods in the overall diet of the population of the southwest during the Pleistocene being uncertain. The picture given by the food resources exploited is added to by the presence of stone tools, as they give clues to the processing and other activities that were taking place in these caves.
Information gained from the study of these sites indicates they were not used as part of a transient economy with limited activities (Lourandos, 1983: 88), rather they display a degree of structuring of their economy that has not been recorded from any other Pleistocene sites in Australia. These sites appear to indicate that the behavioural pattern in this region was unique, their signatures being different from those of sites in southeastern Tasmania that have been dated to the Pleistocene. The authors suggest it is not reasonable to ascribe the behavioural pattern of the southwest as a likely pattern in all Australian human populations of the Pleistocene (Lourandos, 1987: 158). According to the authors the residues of the southwest differ from those found in inland karst caves that have been dated to the Pleistocene, that are widely dispersed around Australia. Examples of such caves are Cloggs Cave in Victoria (Flood, 1980: 254), Devil's Lair, Western Australia (Dortch, 1984), Walkunder Arch, north Queensland (Campbell, 1984: 176) and Colless Creek, western Queensland (Hiscock, 1984). In the Pleistocene, the cave deposits of southwestern Tasmania differ in many ways from the sites mentioned above in other parts of Australia, being as different as are the Holocene sites in southeastern Tasmania from those on the mainland of a similar age. The authors suggest the subtle differences between early Australian sites should be studied in more detail, and not the continued highlighting of the similarities of Late Pleistocene residues, 'and by implication the continuity and unidirectional vectors of Pleistocene human behaviour' (Cosgrove, Allen & Marshall in Source 1).
For more information, illustrations and photos see Source 1.
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