RYAN J. RABETT. Human adaptation in the Asian Palaeolithic: hominin dispersal and behaviour during the Late Quaternary. xii+372 pages, 73 illustrations, 10 tables. 2012. Cambridge: Cambridge University Press; 978-01-107-01829-7 hardback £65 & $99.
Review by Michael Petraglia
School of Archaeology, University of Oxford, UK
Good books on the Palaeolithic of Asia are hard to find. Thankfully, Ryan Rabett has produced a quality volume that synthesises important information about human occupation history in a poorly known region of the world.
At first glance, the title of this book promises to provide the reader with detailed information about the long history of hominin adaptations in Asia as a whole. Yet, many areas of Asia are only cursorily summarised (perhaps not surprising given that Asia covers 30 per cent of the world's total land surface area), and the evidence for Lower and Middle Pleistocene occupations is only thinly reviewed (again, perhaps unsurprising given that the span of human history ranges back nearly two million years). The practical reality behind the title of the book is that the majority of this work is dedicated to the last 40 000 years of human occupation history in Asia, with a particular focus on Southeast Asia.
In the introductory chapter, Rabett lays out three important propositions to be explored in the book. The first proposition is "that modern human behaviour is evolutionarily emergent rather than attained" (p. 6). Connected to this, Rabett argues that it is likely that hominins experienced "strong external selective pressures prior to the Holocene and stronger internal selection pressures thereafter" (p. 6). These are certainly important avenues of research that should appeal to any scholar interested in the degree to which human populations were shaped by, or interacted with, their environments. Though Rabett makes the logical conclusion that 'modern human behaviour' is not the exclusive domain of our own species, correctly indicating that evidence points to regional differences in hominin behaviour, there is little in this book that documents the adaptive and cultural variations in early hominins. While one can also generally agree with Rabett that climate change likely played a significant role in conditioning early hominin responses and adaptations on a regional level, little information on behaviour is provided in Chapter 3 (on Lower and Middle Pleistocene hominins) which allows investigators to evaluate the degree to which hominins were able to actively construct and modify their physical and social niches to improve their chances of survival. This problem, in part, is likely related to the quality of information currently obtainable from early Pleistocene sites in Asia.
The degree to which external and internal selective forces acted on humans is more firmly treated in Chapters 6 and 7, which entail detailed treatments of the Southeast Asian record in the Last Termination (i.e. 22 000–11 700 cal BP) and the Early Holocene. Chapter 6 is a masterful discussion of regional climate, human genetics and technological change, the latter forming the majority of the chapter. Technologies made from bone, lithic and shell are examined in great detail across Sunda. Most impressive is the compilation of information on bone technology (bone points and a variety of shaped implements), which shows significant temporal and geographical variation. Review of lithic technologies across Sunda reveals the range of formal and informal tool types used (e.g. projectile points, tanged blades, scrapers, pebble tools). This technological information nicely sets up Chapter 7, which examines variations in subsistence strategies. Here faunal assemblages from three principal areas are examined: the Niah Caves (Borneo), the Hang Boi Cave (Vietnam) and the caves of Gua Sagu and Gua Tenggek (Malaysia). Tropical subsistence strategies are shown to incorporate an incredible array of vertebrate and invertebrate species that vary in the degree to which they were incorporated into the dietary economy of foraging populations. This new formulation then allows Rabett to examine the degree to which external and internal forces operated on prehistoric cultures. In the concluding chapter of the book (Chapter 8), Rabett suggests that Pleistocene human adaptations are mostly a response to climatic and ecological instability, whereas in the Holocene, the explosion of diversity across cultural groups emerges out of the adoption of different adaptive and social strategies.
Rabett's second proposition is that "the increasing pace of climatic instability was a premier driver in hominin dispersive and adaptive trajectories since at least the last inter-glacial" (p. 6). Chapter 5 takes up the question of the initial dispersal of Homo sapiens across Asia, examining environmental, genetic and archaeological evidence from north-eastern Africa to Southeast Asia. The 'Southern Route Hypothesis' is examined relative to climatic trends and a novel compilation of environmental and archaeological evidence across South Asia, Sundaland, Wallacea, Sahul and western Melanesia. Though regional differences in chronology, material culture and adaptations are revealed, the quality of the data forces Rabett to conclude that "[a]lthough there is good reason to believe that climatic and environmental instability of the Late Pleistocene are strongly linked to regional developments in hominin behavioural adaptations, there is not yet sufficient chronological resolution to confidently match archaeological trends to environmental ones" (p. 140). A richer data-set is presented on the relationship between climate and dispersals in Chapter 6, where late- to post-glacial environmental changes are examined relative to genetic, technological and subsistence trends. The picture that emerges from archaeological research, and genetic studies, is that the adaptive and demographic history of Southeast Asia is intricate and complex—in part, likely tied to the effects of flooding of the Sunda Shelf after the Last Termination.
Finally, the third proposition of the book is that "regionalism in H. sapiens behaviour developed to a significant degree through the demographic and acclimation processes of colonising new or remodelled environments under these conditions of climatic caprice" (p. 6). The point here is that evolutionary trajectories of cultural behaviours across Asia must be understood in regional and local contexts, thus allowing archaeologists to decipher the numerous ways in which humans responded to climatic instability and their transformed environments. Rabett effectively demonstrates temporal and spatial variations in behaviour across Southeast Asia, thereby highlighting the need to compare and contrast regional cultural responses across Asia.
The concluding chapter (Chapter 8) nicely summarises the three main propositions made in the book, but it also expands upon them in a thoughtful conceptual model that centres on the underlying factors to be considered in understanding colonisation and re-colonisation events. The record of population change in Southeast Asia is examined under four descriptive phases: transference (the initial exploitation of a new environment), diversification (the way in which a colonising population settles and adapts to a new setting), innovation (the relations between innovative behaviour and demography) and divergence (the evolution of existing knowledge domains into more locally pertinent ones).
In sum, this book is an excellent new contribution on the Late Pleistocene history of Southeast Asia. The book challenges archaeologists to think about how their regional records developed in response to external and internal influences, ultimately leading to, as Rabett aptly puts it, "a Pleistocene 'explosion' of new life ways" (p. 290).