Out of Eden: The Peopling of the World (58 page)

Australian lineages have been rather less well characterized, but Redd and Stoneking (op. cit.) group them with Asians (specifically Indians – with rather less justification), rather than with Africans (see e.g. their Fig. 4). See also Ingman et al. (op. cit.), who show that Haplogroups 2 and 3 form a unique N subgroup and that Haplogroup 23 is a unique M type. No non-M/non-N Australian lineages have been demonstrated so far.

6.
A recent article co-authored by Alan Thorne, a leading multiregionalist, suggested, on the
basis of mtDNA results from ancient Australian bones, that some Australians may have left Africa in an earlier migration: Adcock, G.J. et al. (2001) ‘Mitochondrial DNA sequences in ancient Australians: Implications for modern human origins’
Proceedings of the National Academy of Sciences USA
98
(2): 537–42. An immediate response from scientists working in the same field roundly condemned the study on the basis of methods, data presented, and underlying argument: Cooper, A. et al. (2001) ‘Human origins and ancient DNA’
Science
292
: 1655–6. The discussion is rather technical and involved,
and
I mostly agree with the counterarguments given in the response by Cooper, A. et al. Mainly at issue was mtDNA extracted from one of the oldest sets of skeletal remains (possibly 62,000 years old – a date challenged again recently) found at Lake Mungo in the Willandra Lakes region of south-west Australia (LM3). Adcock and co-authors (op. cit.) argued that this mtDNA came from an earlier human branch. Cooper et al. (op. cit.) convincingly undermined their claim.

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 op. 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).