Out of Eden: The Peopling of the World

by Oppenheimer, Stephen

  A significant aspect not disputed by either side was that the skull of the LM3 individual (and all others of the same vintage) was anatomically modern and gracile (light-boned), like those of most modern non-Africans. So there still seems little doubt that the first immigrants to Australia were descendants of the single out-of-Africa movement. So far, there is no convincing genetic evidence among living Aboriginal Australians to challenge this view (but see my qualifications below).

  To do justice to the multiregionalists, however, there remains a significant problem with later prehistoric Australian skulls, which had much more robust (heavy-boned) features. These skulls, found in Kow Swamp and the Willandra Lakes region of south-west Australia and dated to approximately the last glacial maximum (LGM) onwards, are best represented by the WLH50 skullcap. These could possibly represent a secondary migration into Australia at the very low sea level of the LGM. This scenario is implicit (if not explicitly noted) in the discussion by the leading multiregionalist Milford Wolpoff (Wolpoff, M. (1999) Paleoanthropology (McGraw-Hill, Boston) pp. 738–40). Multiregionalist Alan Thorne had argued that these robust skulls may represent another species, Java Homo erectus, who hybridized with the gracile type (Thorne, A.G. (1980) ‘The longest link: Human evolution in Southeast Asia and the settlement of Australia’ in J. Fox et al. (eds) Indonesia: Australian Perspectives (Australian National University, Canberra) pp. 35–43).

  Physical anthropologist and archaeologist David Bulbeck has recently reviewed available information on this topic and, while favouring local evolution rather than di-hybrid theory, in the concluding passages he confesses that the evidence does not allow one to rule out the circa-LGM secondary colonization of Australia by robust people, themselves partly descended from Java Homo erectus (Bulbeck, D. (2001) ‘Robust and gracile Australian Pleistocene crania: Tale of the Willandra Lakes’ in T. Simanjuntak et al. (eds) Sangiran: Man, Culture and Environment in Pleistocene Times (Yayasan Obor Indonesia, Jakarta) pp. 60–106).

  This remaining doubt has echoes in the controversial Adcock mtDNA data; mtDNA from KS8 (one of the six robust specimens described in Adcock et al. (op. cit.) and over 8,000 years old) then becomes much more interesting than LM3. On their tree, KS8 segregates from all other Australians, both modern and prehistoric. If one accepts KS8 as a valid DNA result, on the basis that the DNA is much younger and presumably more viable than others described in the paper, it can be found an approximate place early on the modern African human mtDNA tree. The Most Recent common Ancestor for all modern humans (African Eve) should have mutational differences from the European Control Region Sequence at sites 16223, 16278, 16187, (16189, 16311, 16230, 16148, and 16320. I have written these mutation sites progressively backwards on the tree towards the African Eve (MRCA). KS8 differs from the CRS at 16223, 16278, 16311, 16230, and 16284. This tends to put her way back in the African L1 branch towards the modern African Eve, whose age approaches 200,000 years (note that the genetic coalescent date estimate can be older or younger than the apparent anatomical split). This could be consistent with the mtDNA ancestor of KS8 having left Africa separately as a robust but probably modern Homo sapiens type either long before, at the same time as or even after the main exodus of moderns 60,000–80,000 years ago. Therefore having an L1 haplotype would not suggest that KS8 had a Homo erectus hybrid maternal source, merely an earlier modern one.

  Similar mtDNA haplotypes sharing the 16223 and 16278 mutations appear in an Australian and Melanesian data set including Eastern Indonesians (Haplotypes 162–165 in Redd and Stoneking op. cit.). Similarly, four other non-African haplotypes belonging to African L1 and L1b haplogroups were reported by Vigilant and colleagues (Vigilant, L. et al. (1991) ‘African populations and the evolution of human mitochondrial DNA’ Science 253: 1503–7). Two of these were described as Asian (Haplotypes V23 and V28), one as Australian (Haplotype V49), and one as being from the Pacific island of New Britain (Haplotype V50). Three of these four came from the data set of Rebecca Cann’s famous Nature paper (Cann, R. et al. (1987) ‘Mitochondrial DNA and human evolution’ Nature 325: 31–6). Such arguments for older African intrusions to the Antipodes have to remain speculative until (and if) ancient mtDNA from more robust fossil specimens as well as modern Australians is analysed in more detail. If such a model of a separate modern exodus carrying pre-L3 mtDNA haplotypes, which occupied Eastern Indonesia and subsequently migrated to Australia at the LGM 20,000 years ago, were substantiated, it might well pose a challenge to the hypothesis of a single out-of-Africa movement.

  7. Until the 1990s, there was no clear evidence for humans in Australia: Roberts, R.G. and Jones, R. (2001) ‘Chronologies of carbon and of silica: Evidence concerning the dating of the earliest human presence in Northern Australia’ in P.V. Tobias et al. (eds) Humanity from African Naissance to Coming Millennia (Florence University Press, Firenze; Witwatersrand University Press, Johannesburg) pp. 239–48. limitations of the radiocarbon method of dating: ibid; see also note 7, Chapter 3. between 50,000 and 60,000 years ago: this was for the Malakunanja II shelter; Roberts and Jones later obtained similar dates for the nearby Nauwalabila I shelter: Roberts, R.G. et al. (1990) ‘Thermoluminescence dating of a 50,000 year-old human occupation site in northern Australia’ Nature 345: 153–6; Roberts, R.G. et al. (1994) ‘The human colonisation of Australia: Optical dates of 53,000 and 60,000 years bracket human arrival at Deaf Adder Gorge, Northern Territory’ Quaternary Science Reviews (Quaternary Geochronology) 13: 575–83.

  8. the rock art site of Jinmium: Fullagar, R.L.K. et al. (1996) ‘Early human occupation of northern Australia: Archaeology and thermoluminescence dating of Jinmium rock-shelter, Northern Territory’ Antiquity 70: 751–73. two to three times as old as the Arnhem Land shelters: Roberts et al. (1990, 1994) op cit. the problem appeared to be solved: Roberts, R.G. et al. (1999) ‘Optical dating of single and multiple grains of quartz from Jinmium rock shelter, northern Australia: Part II, results and implications’ Archaeometry 41: 365–95. oldest dates of human occupation in Australia: Since completing the Jinmium study, Roberts and Jones have redated two key samples from the Malakunanja II deposit using the same single-grain optical dating methods. These optical ages confirmed the previous ages for initial human occupation of Malakunanja II but increased somewhat the oldest age in the lowest level containing artefacts, to 61,000 years: Roberts, R. et al. (1998) ‘Single-aliquot and single-grain optical dating confirm thermoluminescence age estimates at Malakunanja II rock shelter in northern Australia’ Ancient Thermoluminescence 16: 19–24.

  9. human occupation dates as old as 62,000 years ago: Simpson, J.J. and Grün, R. (1998) ‘Non-destructive gamma spectrometric U-series dating’ Quaternary Science Reviews (Quaternary Geochronology) 17: 1009–22; Thorne, A. et al. (1999) ‘Australia’s oldest human remains: Age of the Lake Mungo 3 skeleton’ Journal of Human Evolution 36: 591–612. another 80,000 years before: 150,000 years ago at OIS 6, Chappell, J. (1983) ‘A revised sea-level record for the last 300,000 years from Papua New Guinea’ Search 14(3/4): 99–101.

  10. a very deep lowstand: Siddall, M. et al. (2003) ‘Sea-level fluctuations during the last glacial cycle’ Nature 423: 853–8 around 100 metres vertically below today’s levels: ibid.

  11. colonization of Manus Island: Anderson, A.J. (2000) ‘Slow boats from China: Issues in the prehistory of Indo-Pacific seafaring’ in P.M. Veth and S. O’Connor (eds) East of Wallace’s Line: Studies of Past and Present Maritime Cultures of the Indo-Pacific Region, Modern Quaternary Research in Southeast Asia, Vol. 16 (Balkema, Rotterdam) pp. 13–50, here p. 17. random accidental drifts is an unlikely scenario: Stoneking, M. et al. (1990) ‘Geographic variation in human mitochondrial DNA from Papua New Guinea’ Genetics 124: 717–33. 68,000-year-old date: 68,099 years, 95% CI = 55,663–97,350 years, Redd and Stoneking op. cit.

  12. some of the earliest Australian sites: e.g. Mungo Lake – Chapter 3 in Flood, J. (1995) Archaeology of the Dreamtime (Collins, Australia). the beach nearer to its present location: Siddall o
p. cit. the next available lowstand 55,000 years ago: ibid.

  13. Sea routes to Australia and New Guinea and inter-island visibility: Irwin, G. (1994) The Prehistoric Exploration and Colonisation of the Pacific (Cambridge University Press) pp. 18–30.

  14. around 77,000 years: 76,507 years for the PNG highlanders (PNG 2 and 3); 95% CI = 55,663–97,350 years: see Redd and Stoneking op. cit. New Guinea may have been colonized before Australia: This argument is highly speculative since the accuracy of genetic dating is not the best, and the earliest confirmed date of colonization of New Guinea is still only 40,000 years ago. See Groube, L. et al. (1986) ‘A 40,000-year-old human occupation site at Huon Peninsula, Papua New Guinea’ Nature 324: 453–5.

  15. Morwood, M. et al. (2002) ‘The archaeology of land use: Evidence from Liang Bua, Flores, East Indonesia’ paper presentated at the 17th Congress of the Indo-Pacific Prehistory Association, 9–15 September 2002, Taipei, Taiwan.

  16. as long ago as 160,000 years: Mishra, S. (1995) ‘The chronology of the Indian Stone Age: Impact of recent absolute and relative dating attempts’ Man and Environment 20(2): 11–17; see also the discussion in Chapters 1 and 2 (pp. 87, 118) on Sri Lankan microliths. Middle Palaeolithic tools also abound: Amirkhanov, H. (1994) ‘Research on the Palaeolithic and Neolithic of Hadramaut and Mahra’ Arabian Archaeology and Epigraphy 5: 217–28. stone tools similar to those of the African late Middle Stone Age: The tools are undated as yet. See McClure, H.A. (1994) ‘A new Arabian stone tool assemblage and note on the Aterian industry of North Africa’ Arabian Archaeology and Epigraphy 5: 1–16. The North African industry referred to is the Aterian, which spread as far as the western desert of Egypt and is roughly dated from 90,000 years ago onward – McBrearty, S. and Brooks, A.S. (2000) ‘The revolution that wasn’t: A new interpretation of the origin of modern human behavior’ Journal of Human Evolution 39: 453–563).

  17. curious, rather crude, large pebble tools: Similar large quartzite unifacial and bifacial pebble tools classified as Mode 1/2 chopper tools have been found in the southern Yemen. Since they were surface finds and undated, the same attribution to an earlier human species was made. See Whalen, N.M. and Schatte, K.E. (1997) ‘Pleistocene sites in southern Yemen’ Arabian Archaeology and Epigraphy 8: 1–10. tried to relate the tools to the great eruption: Harrison, T. (1975) ‘Tampan: Malaysia’s Palaeolithic reconsidered’ in G.-J. Bartstra and W.A. Casparie (eds) Modern Quaternary Research in Southeast Asia Vol. 1 (Balkema, Rotterdam) pp. 53–70. On Harrison himself, see Heimann. J.M. (1999) The Most Offending Soul Alive: Tom Harrison and His Remarkable Life (University of Hawaii Press, Honolulu).

  18. Majid, Z. and Tjia, H.D. (1988) ‘Kota Tampan, Perak: The geological and archaeological evidence for a late Pleistocene site’ Journal of the Malaysian Branch of the Royal Asiatic Society 61: 123–34; Majid, Z. (1998) ‘Radiocarbon dates and culture sequence in the Lenggong Valley and beyond’ Malaysia Museums Journal 34: 241–9. The end of the Lenggong Valley culture could have been as recent as 4,000 years ago (i.e. into the Iron Age of the region), if the ‘old carbon effect’ of freshwater shell in karstic formations is taken into account (David Bulbeck (2002) personal communication).

  19. Two of the highest authorities: ‘Whatever the final decision on age, the tools appear to be the handiwork of anatomically modern humans’ – Bellwood, P. (1997) Prehistory of the Indo-Malaysian Archipelago revised edn (University of Hawaii Press, Honolulu) p. 68; Bowdler, S. (1992) ‘The earliest Australian stone tools and implications for Southeast Asia’ Indo-Pacific Prehistory Association Bulletin 12: 10–22. The description of Southeast Asian and Australian Palaeolithic tools as ‘crude’ or unsophisticated is more commonly used by archaeologists working in Europe or Africa. Such an appellation is often regarded by archaeologists in Australasia as a biologically determinist and Eurocentric value judgement. tools found in the Lenggong Valley are too recent: Majid (1998) op. cit. finding by her team of the ‘Perak Man’: Majid, Z. (ed.) (1994) The Excavation of Gua Gunung Runtuh and the Discovery of the Perak Man in Malaysia (Department of Museums and Antiquity, Malaysia). He was about 10,000 years old: or as recent as 7,000–8,000 years old if, again, the ‘old carbon effect’ of freshwater shell in karstic formations is taken into account, so Perak Man is probably slightly less than 10,000 years old (David Bulbeck (2002) personal communication).

  20. these kinds of tools (i.e. Mode 1/Chopper-chopping tool complex): see Shutler, R. Jr (1995) ‘Hominid cultural evolution as seen from the archaeological evidence in Southeast Asia’, Conference papers on Archaeology in Southeast Asia, Publ. Hong Kong University Museum, Hong Kong, 1995. In this paper Shutler discounts the very early dates of the Pacitanian stone tool culture in Java. In Bowdler’s reviews (e.g. op. cit.) she also seems to argue that the appearance of any tools in Southeast Asia and the Antipodes coincides with the appearance of modern humans in the region. It has been claimed that Cabengian and Pacitanian artefacts from, respectively, Sulawesi and Java may indicate modern human migrations in Island Southeast Asia by at least 74,000 years ago: Keates, S. and Bartstra, G.-J. (2001) ‘Observations on Cabengian and Pacitanian artefacts from Island Southeast Asia’, Quärtar, Band 51/52: 9–32.

  21. Bellwood op. cit. pp. 68, 160, 168, 316.

  22. Geochemical analysis shows that the Kota Tampan ash belongs to the great 74,000-year-old eruption that also covered India – Shane, P. et al. (1995) ‘New geochemical evidence for the youngest Toba tuff in India’ Quaternary Research 44: 200–204; Westgate, J.A. et al. (1998) ‘All Toba tephra occurrences across peninsular India belong to the 75,000 year bp eruption’ Quaternary Research 50: 107–12; Acharya, S.K. and Basu, P.K. (1993) ‘Toba ash on the Indian subcontinent and its implications for correlation of Late Pleistocene alluvium’ Quaternary Research 40: 10–19. Acharya and Basu note that both Middle and Upper Palaeolithic tools occur in Toba ash-bearing deposits.

  23. Some argue: see e.g. the discussion in Bulbeck, D. (1996) ‘Holocene biological evolution of the Malay Peninsula aborigines (Orang Asli)’ Perspectives in Human Biology 2: 37–61. In the next chapter: see also Bulbeck, D. (1999) ‘Current biological research on Southeast Asia’s Negritos’ SPAFA Journal 9(2): 14–22; Rayner, D. and Bulbeck, D. (2001) ‘Dental morphology of the “Orang Asli” aborigines of the Malay Peninsula’ in M. Henneberg (ed.) Causes and Effects of Human Variation (Australasian Society for Human Biology, University of Adelaide) pp. 19–41.

  24. Hill et al. (2003) ‘Mitochondrial DNA variation in the Orang Asli of the Malay Peninsula’ (in press)

  25. A uranium date of 67,000 years: +6000 –5000, Wu, X. (1992) ‘The origin and dispersal of anatomically modern humans in East and Southeast Asia’ in T. Akazawa et al. (eds) The Evolution and Dispersal of Modern Humans in Asia (Hokusen-sha, Tokyo) pp. 373–8. but has been questioned: Brown, P. (1999) ‘The first modern East Asians? Another look at Upper Cave 101, Liujiang and Minatogawa 1’ in K. Omoto (ed.) Interdisciplinary Perspectives on the Origins of the Japanese (International Research Center for Japanese Studies, Kyoto) pp. 105–30. In December 2002, a Chinese group: Shen Guanjun et al. (2002) ‘U-series dating of Liujiang hominid site in Guanxi, Southern China’ Journal of Human Evolution 43: 817–29; see also the comment in Science News Online 21 December 2002. Their preferred dating of 111,000–139,000 years ago: Shen and colleagues (ibid.) go even further, suggesting that, if correct, the older dates could raise the possibility that the abortive exodus to the Levant 120,000 years ago may not have been quite so fruitless. The precise answer will have to wait for direct dating of the skull itself or of its calcite accretions.

  26. Several studies of Australian maternal clans: See the discussion and references in note 4. large studies of Y chromosomes: Hammer, M.F. et al. (2001) ‘Hierarchical patterns of global human Y-chromosome diversity’ Molecular Biology and Evolution 18(7): 1189–203; Underhill, P.A. et al. (2000) ‘Y-chromosome sequence variation and the history of human populations’ Nature Genetics 26: 358–61; Kayser, M. et al. (2001) ‘Independen
t histories of human Y chromosomes from Melanesia and Australia’ American Journal of Human Genetics 68: 173–90. But see the discussion on prehistoric mtDNA from robust human KS8 discussed in note 6. same pattern is seen with genetic markers: i.e. nuclear markers. The best example of this is seen in a worldwide study of Alu inserts, where a neighbour-joining tree has one branch from Africa giving rise to the rest of the world, showing the Pakistanis, New Guineans, and Australians near the origin of this branch. If the Antipodes were populated by separate migrations, these would form a separate branch from the African root. See Fig. 2 in Stoneking, M. et al. (1997) ‘Alu insertion polymorphisms and human evolution: Evidence for a larger population size in Africa’ Genome Research 7: 1061–71. For individual nuclear gene trees, see also Tishkoff, S.A. et al. (1996) ‘Global patterns of linkage disequilibrium at the CD4 locus and modern human origins’ Science 271: 1380–97; Alonso, S. and Armour, J.A.L. (2001) ‘A highly variable segment of human subterminal 16p reveals a history of population growth for modern humans outside Africa’ Proceedings of the National Academy of Sciences USA 98: 864–9. dates estimated for the African L3 cluster expansion: 77,000 ± 2,400 years, Watson, E. et al. (1997) ‘Mitochondrial footprints of human expansions in Africa’ American Journal of Human Genetics 61: 691–704. This estimate can now be revised with improved resolution of the tree round the L3 node. A more up-to-date estimate of 83,000 years (Oppenheimer, S.J. unpublished, but again using calculation of ‘rho’) can be calculated by using complete sequence data from Ingman et al., op. cit. (The ‘rho’ methods average mutations in daughter branches and multiply by a calibrated constant – Forster, P. et al. (1996) ‘Origin and evolution of Native American mtDNA variation: A reappraisal’ American Journal of Human Genetics 59: 935–45. and Saillard, J. et al. (2000) ‘mtDNA variation among Greenland Eskimos: The edge of the Beringian expansion’ American Journal of Human Genetics 67: 718–26.) This method of estimation also shows that both M and N and the African branches of L3 and L1c re-expanded around 70,000 years ago, presumably after the worldwide effects of the Toba explosion (shown in Figure 8.2). See also the re-estimate of L3 at 83,500 years by an independent method based on maximum likelihood in Hill C. et al. (in preparation) op. cit.