The Incredible Human Journey
Page 17
Alongside the cremation, the archaeologists found stone tools, animal bones and hearths, which provided important clues about the lifestyle of ‘Mungo Lady’ and her people. They ate a varied diet, catching golden perch in the lake and eating shellfish collected from its margins. They also ate emu eggs, small birds and bush meat. The archaeologists examining the clues left on the lake shore decided that the evidence pointed to a few visits to that particular site, by a small group of perhaps one or two dozen people. They suggested that it was a camp that had been used for a few seasons before either being abandoned or getting covered up by sand and mud.
The diet and lifestyle of these ancient Aboriginal people seemed quite similar to that of Aboriginal Australians around the Murray and Darling rivers in the nineteenth century: camping by rivers and lakes in spring and summer, eating fish and shellfish, and moving into the bush in winter, where they would catch and eat a range of marsupials.6 It seems strange in some ways that this ancient lifestyle persisted in Australia, whereas, in different parts of the world, people settled down and started farming. Whatever pressures there were in other places, to give up that nomadic lifestyle and settle down, it seems they were either absent or were somehow overcome in Australia – without necessitating a major change in subsistence strategy.
Six years after the discovery of Mungo Lady, Jim Bowler found another burial in the dunes. A few days later, Jim Bowler and Alan Thorne excavated the burial. This time, the body had been buried, with the hands clasped over the pelvis, and covered in ochre. Its position in the dune again suggested that the burial was about 30,000 years old. This skeleton, Mungo III, was described as being lightly built, but nonetheless male, and was quickly dubbed ‘Mungo Man’.
In 1999, Alan Thorne had another go at dating Mungo Man, this time using ESR and uranium series techniques on the skeleton itself, as well as OSL on sand grains from sediment below the burial. All the results were much older than the previously published dates for Mungo Man. It looked as if the burial could be over 60,000 years old.7 This was an incredible date: it would make Mungo Man the oldest known modern human outside Africa.
Jim Bowler was not convinced by this very early date, and published a paper saying so, entitled: ‘Redating Australia’s oldest remains: a sceptic’s view’.8 He called into question the methods that Thorne had used. He wrote that Alan Thorne had made erroneous assumptions about the composition and erosion of the sediments that Mungo Man had been buried in, which made his ESR and uranium series dates untenable. And he didn’t mince his words when he came to the OSL dates, which Alan Thorne had obtained from samples of sediment not directly next to the skeleton, but from about 400m away.
A few years later, Jim Bowler and a team of scientists published some new dates for Mungo Man and Mungo Lady. Samples of sediment from the burial sites were sent to four different labs for OSL dating, and all came back with dates of around 40,000 years ago.9 These were older than the original radiocarbon dates, but much more believable than the dates published by Thorne’s team. Mungo Man and Lady were still the most ancient Australians known.
Even when I got to Mungo, I wasn’t sure if I was actually going to be able to see the human remains. Ancient skeletons have become symbols of identity for modern Aboriginal people, who feel – and understandably so – that their own heritage and beliefs have been largely disregarded, even trodden underfoot, in the recent past. Colonialism has a lot to answer for. As some attempt to redress the balance, the official policy in Australia was now that prehistoric human remains, however old, should be returned to communities of indigenous people,10 but the implementation of this policy could be quite difficult – but perhaps not for obvious reasons.
It was very interesting talking to Michael Westaway, who had worked for some years on the repatriation of human remains. His experience was that Aboriginal communities often recognised the value of archaeological and anthropological investigation in revealing information about their heritage, and, indeed, saw it as a shared project. Aboriginal groups were keen for ancient human remains to be kept by museums for future research, as long as they were treated with respect.
‘I was stuck in a difficult position,’ he said. ‘I had a quota of human remains to be returned to communities, but the Aboriginal groups I was working with often wanted us to keep the remains.’ It was an interesting conflict: between being seen to be doing the right thing and doing what was actually right, in dialogue with local communities.
At Mungo, the situation was even more complicated, with political tension between the three separate tribal groups, the Barkindji, Ngiyampaa and Mutthi Mutthi, meaning that it had been very hard to achieve a consensus about how and where the human remains should be kept. Mungo Lady had been officially returned into the custody of local Aboriginal groups in 1992. In practice, this meant that the remains were locked away in a strange, painted safe in one of the store rooms of Mungo museum. In contrast, Alan Thorne had been entrusted to curate the remains of Mungo Man in Canberra. These were both temporary arrangements, and Michael Westaway told me about how he was helping the local Aboriginal groups in planning a permanent ‘keeping place’ at Mungo, where the bones could reside, with the three traditional tribal groups maintaining control over who had access to the remains.11 It seemed like a perfect solution to a difficult problem, and I was aware of similar schemes – for much more recent bones – in the UK, where a consecrated ossuary could be used to hold boxes of skeletons, which would still be available for study. Michael was also keen on the idea of a ‘keeping place’ at Willandra as he felt that it would further strengthen the engagement of the Aboriginal community in any future research.
The air was thick with politics at Mungo. Although the elders of the Barkindji and Ngiyampaa tribes gave their permission, in principle, for me to see the remains of Mungo Lady, it seemed that the key to the safe had been given to a certain Badger Bates, who lived hundreds of kilometres away from Mungo. But the elders had agreed to me seeing Mungo Man – and so had Alan Thorne.
So – with a joyful heart – I left dry, dusty and fly-ridden Mungo and headed for Canberra. I was looking forward to meeting both Mungo Man and Alan Thorne. Both were controversial figures in Australian prehistory. Mungo Man’s antiquity was hotly debated as, in fact, was his sex. Although he had been initially reported as male, Peter Brown had subsequently pored over his bones and decided that there wasn’t enough of him preserved to be sure about his sex.12
As well as his very old dates for Mungo Man, Alan Thorne was also well known for his ‘two wave’ hypothesis of Australian origins. He believed in regional continuity, specifically that Homo erectus in nearby Java had evolved into a robust type of modern human, which had made its way to Australia. Then a second wave of more gracile modern humans had moved in, and hybridised with the first population. In his scheme, lightly built Mungo Man was part of that ‘second wave’, whereas some more robust specimens from Australia had retained characteristics of the earlier, more robust and locally evolved people.
I was sceptical about this theory, but fascinated to meet Alan Thorne himself – and to see the evidence. In a small laboratory in the Australian National University in Canberra, Alan Thorne unpacked Mungo Man from various boxes, under the watchful eyes of Aboriginal elders. The skeleton was very slightly built, and, just as Peter Brown had commented, the parts of the pelvis that would have been so useful in determining ‘his’ sex were damaged and missing. The arm and leg bones were slender, the joints small and the skull was quite female-looking, although the mandible was quite strong-jawed and masculine. I made a mental note: ‘indeterminate sex’. But whether man or woman, this was certainly the skeleton of an anatomically modern human, and a very ancient one.
Then Alan took brought out the WLH 50 skull (‘WLH’ stands for ‘Willandra Lakes Human’: another important fossil find from those strange, dusty, dried-up lakes). This was a specimen that had been discovered sitting on the surface of the shoreline of Lake Garnpung, north of Lake Mungo, in 19
80.10 As it was found ‘out of context’, sitting on the ground surface, it is very difficult to pin a date on WLH 50. It has been dated to about 14,000 years ago by uranium series dating, but about double that by ESR, so the jury is out.13 For Thorne, this was an important specimen in his argument that Homo erectus in South-East Asia had evolved into Homo sapiens.
I looked at the skullcap, sitting there on the table. It had large browridges and a sloping forehead. The whole shape was long and low; it looked fairly erectus-like. I was quite taken aback. But then I picked it up. The bone was very thick and heavy. There are some illnesses that produce thickened bones, like Paget’s disease; this is a strange affliction, of unknown origin, that causes increased bone turnover in the skeleton. Normally, the flat bones of the vault of the skull have a layer of trabecular, or ‘spongy’, bone sandwiched between an inner and outer ‘table’ or plate of dense bone. In Paget’s disease, the skull bones become thicker overall, while the tables thin down and the entire bone takes on a strange spongy appearance. But I could see from the broken edges of the skull bones that the marrow space sandwiched between the dense inner and outer plates of the skull looked normal: not like Paget’s. I still thought it might be pathological. Alan was quick to crush this suggestion.
‘We’ve analysed it and had a hard look at it, and we can’t find any indication of pathology,’ he told me. ‘It’s a very thick – but normal – skull. And there are other sites in Australia that have that thickness of skull bones, like the site that I excavated at Kow Swamp.’
Milford Wolpoff, Professor of Anthropology at the University of Michigan, and perhaps the leading proponent of multiregional evolution, analysed WLH 50 and compared it with other ancient skulls, finding it to be closer to archaic crania from Ngandong, Java, than to the anatomically modern skulls from Skhul and Qafzeh.13 He argued that this was evidence of regional continuity in South-East Asia and Australia. (The Ngandong crania are a bit of a mystery in themselves; some believe them to be late-surviving Homo erectus, others think they are archaic Homo sapiens.14 Recent uranium series dating of these fossils places them at between 40,000 and 70,000 years old.)15 Chris Stringer compared WLH 50 with the Ngandong crania, and with anatomically modern crania from Skhul and Qafzeh, and more recent Aboriginal crania from South Australia. He found that WLH 50 clustered more closely with the modern specimens than with the Javanese fossils, even though it was certainly very long and narrow. He was slightly cautious about his conclusions, though, because he also thought WLH 50 may be pathological.16
Other investigators have also suggested that WLH 50 might be diseased in some way. Biological anthropologist Steve Webb, of Bond University, wrote: ‘The unusual development of the vault structures in this individual has few, if any, equals among other hominins or more recent populations from around the world.’17 So I wasn’t completely mad after all. Webb suggested that the expansion of the marrow space in the skull bones may represent a response to anaemia, and that perhaps this was even a genetic form of anaemia. I was reminded of Stephen Oppenheimer and his research into thalassaemia and malaria resistance in South-East Asia; perhaps this adaptation to one of the most aggressive tropical diseases had already evolved in the ancestors of the first Australians.
The main argument against Alan Thorne’s ‘two wave’ hypothesis is that the robust and gracile skulls he sees as representing two different populations could actually be male and female, from the same group of people. Peter Brown’s analysis of WLH 50 concluded that, while the extreme thickness of the skull was bizarre and very possibly pathological, many of its other features were ‘not unusual for an Aboriginal male’.18 And, while Alan Thorne stuck to his guns, saying that gracile ‘Mungo Man’ was a man, others were less sure.19 Perhaps the differences between WLH 50 and ‘Mungo Man’ could be explained if the former was male and the latter female.
Some researchers had suggested yet another idea: that the extreme robusticity of skulls like WLH 50 and Kow Swamp, which date to 14,000 and 20,000 years ago respectively, was neither due to inherited archaic features from Javanese Homo erectus nor to accentuated ‘maleness’, but, instead, represented some sort of adaptation to the extreme aridity of the LGM. And then the people of Australia became more gracile with the improvement of the climate in the Holocene.20
But Alan was very sure that the skulls he was showing me not only supported a ‘two wave’ theory of the peopling of Australia, but were also evidence for regional continuity in South-East Asia and Australia. He was sceptical about genetics and its contribution to this field of enquiry: he thought too much was missing from the modern gene pool to be able to usefully construct the past. He was much happier arguing from the fossil evidence, and he believed that what other people called Homo erectus, heidelbergenis, neanderthalensis and sapiens were actually all part of one single, but very variable, species.
‘I think there was one Out of Africa,’ he said. ‘I don’t believe in Homo erectus. It’s just an old-fashioned name for the earlier part of modern humans. Today, we’re a polytypic species, with so many variations. And there’s enormous variation in the fossil record as well as among living people.’
It was a view of human evolution that seemed strange to me. I left Alan Thorne’s lab convinced by the deep ancestry of the Aboriginal people of Australia but also unwilling to concede that they might be so different from me as to have developed from Javan Homo erectus. I wasn’t convinced by the fossil evidence for this, although there was certainly something rather odd going on with those robust Australian skulls. I couldn’t quite come to terms with Alan’s very inclusive approach to human origins, fitting everything from Homo erectus onwards into one species. And I thought the genes did have something useful to say.
In fact, my next port of call was to explore what genes could reveal about the earliest Australians. I made my way to Sydney, where I tracked down Sheila van Holst Pellekan, in her lab at the University of New South Wales. Sheila had done a huge amount of genetic work with Aboriginal populations, but her achievements in genetics would have been impossible without her ability to engage individuals who were naturally very suspicious of the motives and intentions behind the research. For Sheila, the Aboriginal people who gave her their DNA were more than donors or subjects in the investigation: they were recipients of the knowledge it revealed. It was true community engagement with science. And, like Raj in Cape Town, she was very clear about the main message contained within the genes: that we were all part of one, fairly young, family, with a recent African origin.
‘I think the overwhelming thing, looking at mitochondrial DNA from different people from all over the world, from Australia, Europe and Africa, is that nearly all of it is the same,’ said Sheila, as she took me through the results of some of her analyses.
‘It’s only little changes every now and then which give us clues as to how the family tree fits together.’
Sheila showed me some sequences of mtDNA, from a range of people with European, African and Australian ancestry. She scrolled through hundreds of As, Cs, Ts and Gs, looking for the rare differences between populations. But the vast majority of the sequence in each person was identical. ‘We’re all so similar inside,’ she said.
The work carried out by Sheila and other geneticists, looking at Aboriginal mtDNA, has shown that all the Australian lineages represent branches of the M and N macrohaplogroups, confirming their recent African origin pedigree.21 And, going back in time, those lineages all coalesce 40,000 years ago, suggesting that Australia must have been colonised by at least that time.22 Comparison with other populations has shown that Aboriginal Australians are very closely related to the indigenous people of Melanesia and New Guinea. Indeed, from the mtDNA tree it appears that Australia and New Guinea were colonised in a single wave, some time around 50,000 years ago.21
There may not be any fossil remains of humans in Australia dating that far back, but there are some very ancient traces of modern human behaviour. In the Northern Territory, archaeologists have found
traces of modern humans that seem to go back as far as 60,000 years ago. This early evidence for modern humans in Australia comes from rockshelters where stone tools and traces of pigment use have been found. There are three rockshelters that have become famous (and infamous) as the earliest archaeological sites in Australia, all in the Northern Territory: Malakunanja, Nauwalabila and Jinmium.
In the 1970s, archaeologists excavated two rockshelters in the Alligator rivers region of Arnhem Land, Malakunanja and Nauwalabila, as part of the World Heritage assessment. The initial radiocarbon dates from these sites were fairly old, at around 20,000 years. In the 1980s, the rockshelters were re-examined by Rhys Jones and luminescence-dating specialist Bert Roberts, and new dates were published for both sites in the nineties. Roberts and Jones claimed that the rockshelters contained evidence of humans from as long ago as 50,000 to 60,000 years.
Malakunanja, a rockshelter in a cliff face near Magela Creek, a tributary of the East Alligator River, features some very recent rock paintings, including depictions of a man wearing Western clothing, rifles and a wheel, but the rockshelter seems to have been used for thousands of years. The ancient artefacts found buried in the sediments included stone tools and evidence of pigment use: grindstones and ochres. Thermoluminescence dating of the sediment in which the oldest artefact was found put it around 61,000 years ago.23 Nauwalabila I is a rockshelter in Deaf Adder Gorge, about 70km south of Malakunanja, formed by a massive, fallen sandstone slab. The archaeologists dug down through 3m of sandy deposits, and found man-made stone flakes all the way down to the clean red sand at the bottom. As well as the stone flakes, they also found a piece of ochre which had been ground down, producing flat facets on its surface – again, evidence of pigment use. OSL dates suggested the earliest occupation levels in the rockshelter dated to between 53,000 and 60,000 years old.24