atti esecutivo 18-12-2000 18:04 Pagina 3 HUMANITY FROM AFRICAN NAISSANCE TO COMING MILLENNIA 3 Foreword There was an air of excitement at Sun City, South Africa, in late June of 1998, as delegates started to arrive for the Dual Congress of the International Association of Human Biologists and the International Association for the Study of Human Palaeontology. For the conference organisers, under chairmanship of Professor Phillip V. Tobias, this was the culmination of four years of hard work and planning and, as Phillip remarked at the opening ceremony, it was also a symbolic homecoming to the continent of humanity’s birth for people from all parts of the world. The delegates did indeed come from far and wide: they travelled from 70 countries and the registration list ran to 745 people, making this the most representative gathering of its kind ever held in Africa. As a venue for the exchange of new information on the biology and ancestry of humankind, the Dual Congress provided ample scope. The programme was built around 18 Colloquia, in which 95 invited papers were delivered, and 11 Open Scientific Sections, covering a wide range of topics, discussed in 103 papers, as well as in 79 poster presentations. Nor were the contributions of South African pioneers in the field forgotten: the Raymond Dart Memorial Lecture was given by Sir Walter Bodmer while Professor Tobias delivered the Robert Broom Memorial Lecture, the text of which is reproduced in this volume, together with those of 38 invited papers presented in the Colloquia of the Dual Congress. In addition to all this however, I believe that the occasion was a celebration for another important reason: it was a demonstration of South Africa’s re-acceptance into the wide world of international science with respect to human biology and palaeontology. During the apartheid era, science in this country passed through a bleak period when people like myself had difficulty in travelling to many African countries on a South African passport and when the focus of public interest, with respect to human origins, shifted from this country, where the initial critical finds had been made, to East Africa, where spectacular fossils were coming to light. Such discoveries in lake-side and alluvial deposits certainly have the advantage of precise radiometric dating from associated volcanic ashbeds. But the palaeontological and cultural treasures from our South African caves should never be underestimated. They have yielded vital insights into human origins during the dark times of recent years and will continue to do so into a brighter future. In all respects, the Dual Congress reflected in this volume, was a milestone occasion for South Africa and for international science at large. It was a privilege for me to have been associated with it C. K. Brain Honorary President, The Dual Congress Pretoria 1999 atti esecutivo 18-12-2000 18:05 Pagina 91 HUMANITY FROM AFRICAN NAISSANCE TO COMING MILLENNIA 91 Susan C. Antón1, Plio-Pleistocene Homo: Patterns and Fachroel Aziz2 & Determinants of Dispersal 3 Yahdi Zaim The first 2.5 million years of hominid history is characterized by limited dispersals similar to those of the living great apes whose 1 Department of Anthropology home range sizes very little between years. Unlike our closest University of Florida, Gainesville relative Pan, who are particulary vulnerable during dispersal FL 32611 USA because the distribution of their resources is highly habitat specific and predation takes a relatively higher toll than it does in 2 Geological Research & Development r-selected animals, hominids are widely dispersed after 1.8 Ma. Center, Bandung 40122, Indonesia Hominid dispersal must have entailed either a shift in the types of 3 Department of Geology resources exploited or a technological advance to ensure resource Institute of Technology availability or both. Using data from ecology, geochronology, Bandung, 40132, Indonesia morphology, and paleontology we assess the initial hominid dispersal from Africa and the relationship to patterns of dispersal in nonhuman primates and large mammals of both ‘widely dispersing’ and ‘non-dispersing’ species. The dispersal rates of Plio/Pleistocene hominids differ from those of nonhuman primates and are typical of widely-dispersing large mammals. In fact, H. erectus first appears in Java almost immediately after its appearence in Africa, yet its first appearence in Java is contemporaneous with that of Colobus, Macaca, and Pongo that had already inhabited mainland Asia for millions of years. Although the timing of the first hominid dispersal pre-dates significant technological advances, the energy required by larger hominid body/brain sizes suggest a shift to exploitation of high- protein packages that, according to correlation between faunal and chronometric sequences, is itself dispersing. These data suggest that it is at the origin of H. erectus (sensu lato) that our uniquely Keywords: Homo erectus, biological human dispersal capabilities began to emerge and that this invasions, energetics, diffusion coefficient, dispersal is not primarily due to the technological innovation of Indonesia, Africa the Acheulean tradition. Introduction The global distribution of Homo sapiens contrasts with the restricted ranges of our closest living primate relative, Pan. Yet for some three million years after our lineages diverged, both were apparently exclusively African phenomena, as Pan remains today. These current biogeographic differences are reflected in home range (HR) sizes that are some 15 to 100 times greater in recent human hunter- gatherers than in Pan. (23 hectares in Pan, 330-2600 in humans; Leonard and Robertson, 2000). Although an extensive literature considers the significance of the behavioral repertoire that allows the final, relatively late, dispersal of Homo sapiens into Australasia, North and South America, and Siberia (e.g., Lindly & Clark, 1990; Roberts et al., 1991; Davidson & Noble, 1992; Jelinek, 1994; Waters et al., 1997), the origin of this difference in dispersal patterns is not well understood. The original hominid dispersal from Africa has been viewed as a largely hominid (technologically) driven rather than ecologically driven phenomenon. Such scenarios are based on the idea that widely atti esecutivo 18-12-2000 18:05 Pagina 92 92 S.C. ANTON, ET AL. - Plio-Pleistocene Homo Dispersal dispersed ex-African hominids are not found before 1.0 ma (Pope, 1983) or are not found before the development of the Acheulean (Wolpoff, 1999), and thus that there was a delay of nearly 1.0 my between the appearance of relatively large-brained/bodied hominids in Africa and their wide dispersal from Africa. This delay, or rather the acquisition of the ability to leave Africa, has been attributed to increasingly complex cognitive and technological capabilities typified by the Acheulean tradition (Wolpoff 1999:443) that likely signalled a shift in subsistence ecology (Klein, 1989:219). That is, technological and cognitive innovation allowed or sparked the original hominid dispersal from Africa. Such a scenario has certain detractions including the fact that Acheulean type handaxes are rare or absent in East and Southeast Asian sites that form the earliest and geographically most distant ex- African record (e.g. Movius, 1948; Beltwood, 1985; Keates, 1994) and that other mammals, including carnivores, megaherbivores, bovids, and equids dispersed between Africa and Asia without aid of Acheulean technology (Kurten, 1968; Antures, 1989; Opdyke, 1995). Likewise, hints from radiometric dating suggested that ex-African hominid sites existed in Southeast Asia much in excess of 1.0 Ma (Jacob & Curtis, 1971). Recent work in Java has confirmed not only the greatest age of 1.81 Ma for Mojokerto (Perning I), but has also shown that the main hominid bearing strata at Sangiran are all older than 1.0 Ma (Swisher et al., 1994; Swisher, 1996). Other Asian and West Asian sites have also been suggested to predate 1.0 Ma including Longuppo (China, 1.8 Ma), Dmanisi (Georgia, 1.7 Ma), and Ubeidiya (Israel, 1.3-1.4 Ma; Tchernov1987; Gabunia & Vekua, 1995; Huanget al., 1995). For the purposes of dispersal pattern, however, it is the oldest and geographically most distant evidence that is of greatest importance (see below). Although the Javan dates stand at odds with conventional wisdom, the data are numerous, internally and stratigraphically consistent and based on more reliable radiometric techniques (argon-argon) than previous temporal estimates (either fission-track or biostratigraphy; e.g., Sondaar, 1984; Watanabe & Kadar, 1985). Likewise, the uncertainties surrounding the provenience of the Javanese fossil hominids have been grossly overstated; for some, provenience is unknown, but others, or portions of others, were found in situ (e.g, von Koenigswald, 1940; Anton & Franzen, 1997), and for still others the purported find sites have been confirmed by chemical analysis (Matsu'ura, 1982). These data continue to place most of the Sangiran hominids in the Bapang (Kabuh) formation (as old as 1.5 Ma) and some hominids in the upper Sangiran (Pucangan) formation (1.66 Ma; Swisher et al., 1994; Swisher, 1996). In addition, fauna from the two formations exhibit significant preservational differences resulting from the compaction of bone by the black clays of the Sangiran formation. These differences are also present in the hominids from the Sangiran formation but not those from the Bapang formation. Thus mounting evidence suggests a much earlier exodus from Africa than originally conceived. The timing of the earliest ex-African sites no longer supports the idea that a cognitive delay preceded the first hominid dispersal since the earliest hominids from Java predate or are coeval with the appearance of the first of the larger bodied/brained hominids in Africa (H. erectus, sensu lato) and with the earliest occurrence of the Acheulean (1.4–1.6 Ma; Asfaw et al., 1992). In addition, the first ex- African areas occupied by H. erectus could be accessed via southern continental Asia without the substantial environmental shift required by the later, more northerly occupations by H.