Leslie C. Aiello

Evolution of early Homo: An integrated biological perspective

Background Until recently, the evolution of the genus Homo has been interpreted in the context of the onset of African aridity and the expansion of open grasslands. Homo erectus was considered to be a bona fide member of the genus Homo, but opinions diverged on the generic status of earlier, more fragmentary fossils traditionally attributed to Homo habilis and Homo rudolfensis. Arguments about generic status of these taxa rested on inferred similarities and differences in adaptive plateau. However, there was near-universal agreement that the open-country suite of features inferred for Homo erectus had evolved together and provided the adaptations for dispersal beyond Africa. These features foreshadowed those of more recent Homo sapiens and included large, linear bodies, elongated legs, large brain sizes, reduced sexual dimorphism, increased carnivory, and unique life history traits (e.g., extended ontogeny and longevity) as well as toolmaking and increased social cooperation. Hominin evolution from 3.0 to 1.5 Ma. (Species) Currently known species temporal ranges for Pa, Paranthropus aethiopicus; Pb, P. boisei; Pr, P. robustus; A afr, Australopithecus africanus; Ag, A. garhi; As, A. sediba; H sp., early Homo >2.1 million years ago (Ma); 1470 group and 1813 group representing a new interpretation of the traditionally recognized H. habilis and H. rudolfensis; and He, H. erectus. He (D) indicates H. erectus from Dmanisi. (Behavior) Icons indicate from the bottom the first appearance of stone tools (the Oldowan technology) at ~2.6 Ma, the dispersal of Homo to Eurasia at ~1.85 Ma, and the appearance of the Acheulean technology at ~1.76 Ma. The number of contemporaneous hominin taxa during this period reflects different strategies of adaptation to habitat variability. The cultural milestones do not correlate with the known first appearances of any of the currently recognized Homo taxa. Advances Over the past decade, new fossil discoveries and new lines of interpretation have substantially altered this interpretation. New environmental data sets suggest that Homo evolved against a background of long periods of habitat unpredictability that were superimposed on the underlying aridity trend. New fossils support the presence of multiple groups of early Homo that overlap in body, brain, and tooth size and challenge the traditional interpretation of H. habilis and H. rudolfensis as representing small and large morphs, respectively. Because of a fragmentary and distorted type specimen for H. habilis two informal morphs are proposed, the 1813 group and the 1470 group, that are distinguished on the basis of facial anatomy but do not contain the same constituent fossils as the more formally designated species of early Homo. Furthermore, traits once thought to define early Homo, particularly H. erectus, did not arise as a single package. Some features once considered characteristic of Homo are found in Australopithecus (e.g., long hind limbs), whereas others do not occur until much later in time (e.g., narrow pelves and extended ontogeny). When integrated with our understanding of the biology of living humans and other mammals, the fossil and archaeological record of early Homo suggests that key factors to the success and expansion of the genus rested on dietary flexibility in unpredictable environments, which, along with cooperative breeding and flexibility in development, allowed range expansion and reduced mortality risks. Outlook Although more fossils and archaeological finds will continue to enhance our understanding of the evolution of early Homo, the comparative biology of mammals (including humans) will continue to provide valuable frameworks for the interpretation of existing material. This comparative context enables us to formulate and test robust models of the relationships between energetics, life history, brain and body size, diet, mortality, and resource variability and thereby yield a deeper understanding of human evolution. Pleistocene people and environments In the past few decades, hundreds of hominin fossils have been recovered from well-dated sites in East Africa. In addition, early representatives from far outside Africa have been found in Asia and Europe. Recently, discoveries at Malapa in South Africa and at Dmanisi in western Asia have brought important new fossils and archaeological residues to light. Analyses of local stratigraphy, windblown dust, sea and lake cores, and stable isotopic analyses have improved the reconstruction of ancient environments inhabited by early humans. Antón et al. review recent evidence and arguments about the evolution of early Homo, arguing that habitat instability and fragmentation imposed an important selective force. Science, this issue p. 10.1126/science.1236828 Integration of evidence over the past decade has revised understandings about the major adaptations underlying the origin and early evolution of the genus Homo. Many features associated with Homo sapiens, including our large linear bodies, elongated hind limbs, large energy-expensive brains, reduced sexual dimorphism, increased carnivory, and unique life history traits, were once thought to have evolved near the origin of the genus in response to heightened aridity and open habitats in Africa. However, recent analyses of fossil, archaeological, and environmental data indicate that such traits did not arise as a single package. Instead, some arose substantially earlier and some later than previously thought. From ~2.5 to 1.5 million years ago, three lineages of early Homo evolved in a context of habitat instability and fragmentation on seasonal, intergenerational, and evolutionary time scales. These contexts gave a selective advantage to traits, such as dietary flexibility and larger body size, that facilitated survival in shifting environments.

Human Biology and the Origins of Homo

New fossil discoveries relevant to the origin of Homo have overturned conventional wisdom about the nature of the australopiths and early Homo, and particularly Homo erectus (including Homo ergaster). They have eroded prior assumptions about the differences between these genera and complicated interpretations for the origin and evolution of Homo. This special issue surveys what is now known about the fossil evidence and the environmental context of early Homo. It also moves beyond the hard evidence and sets the stage for integrated, multidisciplinary studies to provide a framework for interpretation of the hard evidence. The underlying premise is that to understand the adaptive shifts at the origin of Homo, it is essential to have a solid understanding of how and why modern humans and other animals vary. Contributors to this issue include paleoanthropologists, human biologists, behavorialists, and modelers. We tasked each with bringing her or his special expertise to bear on the question of the origins and early evolution of Homo. The papers in this collection are a product of a week-long Wenner-Gren symposium held in March 2011, and this introduction integrates this work and its significance for Homo.

Studying extant species to model our past.

The cover caption for the Special Section on Ardipithecus ramidus (2 October 2009, p. [60][1]; cover caption, p. 5) echoed a conclusion threaded among the Research Articles: Ar. ramidus appears to be so different from Pan that “extant great apes are poor models for our last common ancestor.” We

The Wenner-Gren Symposium Series An Introduction by the President

This special issue of Current Anthropology marks the first in a new biannual series of supplements that will publish papers resulting from Wenner-Gren-sponsored symposia. These symposia (originally called Wenner-Gren International Symposia and now simply Wenner-Gren Symposia) are intensive workshop meetings that bring together international scholars for discussion and debate of topical issues in the field.

Engaged Anthropology: Diversity and Dilemmas

Engaged Anthropology: Diversity and Dilemmas grew out of a Wenner-Gren-sponsored workshop titled “The Anthropologist as Social Critic: Working toward a More Engaged Anthropology” held at the foundation headquarters in New York City, January 22–25, 2008 (fig. 1). The workshop was organized by Setha M. Low (Graduate Center, City University of New York) and Sally Engle Merry (New York University). Both Low and Merry have had long-term interests in engaged anthropology, and this was one of the leading themes of Low’s presidency of the American Anthropological Association (2007–2009). The Wenner-Gren-sponsored meeting led to an AAA Presidential Symposium of the same title held at the 107th annual meeting in November 2008. The overall theme of the AAA meetings that year was “Inclusion, Collaboration, and Engagement.” The major focus of Low and Merry’s Wenner-Gren workshop, subsequent AAA Presidential Symposium, and current supplementary CA issue is the history and nature of engaged anthropology, its expansion and growth in the United States and abroad, and the dilemmas it raises. Low and Merry stress that the major contribution of this volume is to illustrate the breadth of forms of engagement. In their words, this extends “from basic commitment to our informants, to sharing and support with the communities with which we work, to teaching and public education, to social critique in academic and public forums, to more commonly understood forms of engagement such as collaboration, advocacy, and activism” (Low and Merry 2010, in this issue). Among the dilemmas that remain unresolved are the ethics of intervention, the appropriateness of critique given the anthropologist’s position, and the hazards of working with powerful government and military organizations. Engagement has been a continuing interest of the WennerGren Foundation. One of the first meetings organized by the foundation was Man’s Role in Changing the Face of the Earth (Thomas 1956). This was a pioneering anthropological ini-

The Origins of Agriculture: New Data, New Ideas Wenner-Gren Symposium Supplement 4

The Origins of Agriculture: New Data, New Ideas resulted from a Wenner-Gren-sponsored symposium held at the Hacienda Temozon, Merida, Yucatan, Mexico, March 6–13, 2009 (fig. 1). The symposium was organized by T. Douglas Price (University of Wisconsin–Madison and the University of Aberdeen) and Ofer Bar-Yosef (Harvard University). The major aim of the symposium was to better understand the origins of agriculture in light of new fieldwork, new sites, new analytical techniques, and more radiocarbon dates. The global nature of agricultural origins was a key theme, and a major focus of the discussions was on East Asia as well as lesser-known regions such as Papua New Guinea, Africa, and eastern North America, alongside more traditional areas such as the Near East and Mesoamerica. The papers presented in this supplementary issue are designed to provide the latest information on the antiquity of agriculture covering at least 10 different centers of domestication. The organizers, Price and Bar-Yosef, note in their introduction that emerging data point to an unexpected synchronicity in the timing of the first domesticates around the end of the Pleistocene. They also note that, contrary to earlier thought, the environments in which agriculture originated were not marginal and that agricultural experimentation took place in areas of concentrations of populations and resources. Each major area may also have included multiple loci for domestication. These were major areas of agreement in a meeting that was characterized by lively debate over the variety of hypotheses proposed for agricultural origins and whether global or more area-specific explanations were most appropriate. As in any good meeting, there were more questions than answers, but this is the sign of a dynamic field. The degree of collegiality and collaboration among the diverse symposium participants and the speed at which new data are accumulating are good signs that our understanding of this important period in human adaptation will continue to evolve rapidly. The Wenner-Gren Foundation has had a long-standing in-

Politics of the Urban Poor: Aesthetics, Ethics, Volatility, Precarity

Politics of the Urban Poor is the 148th symposium in the Wenner-Gren symposium series and the eleventh symposium to be published as an open-access supplementary issue of the Foundation’s journal, Current Anthropology. The symposium was organized by Veena Das (Johns Hopkins University) and Shalini Randeria (Institute for Human Sciences, Vienna, Austria, and Graduate Institute of International and Development Studies, Geneva, Switzerland) and held September 20–26, 2013, at Hotel Villa Luppis, Rivarotta di Pasiano, Pordenone, Italy (fig. 1). The main theme of the symposium was that the lives of urban poor, and particularly their various forms of political involvement and activism, are shaped by a myriad of factors that go beyond basic material scarcity. There are 17 contributions in this collection, including a substantive introduction by the symposium organizers, Das and Randeria (2015). These contributions cover a wide geographic range from South Asia, to Africa, to the Middle East, and to Latin America, and they demonstrate clearly that there is no single culture of poverty resulting in uniformity of life and expression. Although it is clear that poverty may adversely affect the capacity and nature of individuals and of collective action, the purpose of this collection is to examine and interrogate the varied accounts of politics in the daily lives of the urban poor living under a wide range of conditions around the world and tease out the factors that underlie the observed heterogeneity. Four major questions form the basis for the examination of the relationships between urban transformations, poverty, and various forms of democratic politics. The first is the nature of the relationship between government and politics in relation to basic amenities such as water, sanitation, electricity, and housing. The second is the nature of solidarity and antagonism within poor communities in the context of locality, kinship, and work. The third is the effect of violence and specifically how urban decay and institutional corrosion either negate politics or result in collective action that becomes an end in itself (e.g., protests, gang violence). And the fourth is

Potentiality and Humanness: Revisiting the Anthropological Object in Contemporary Biomedicine

Potentiality and Humanness: Revisiting the Anthropological Object in Contemporary Biomedicine is the seventh WennerGren Symposium to be published as an open-access supplement of Current Anthropology and the 144th symposium in the Wenner-Gren symposium series (see http://www.wennergren.org /history/conferences-seminars-symposia/wenner-gren-symposia for a complete list of symposia and the history of the symposium program). The Potentiality and Humanness symposium was organized by Klaus Hoeyer (University of Copenhagen, Denmark) and Karen-Sue Taussig (University of Minnesota, U.S.A.) and was held October 28 to November 4, 2011, at the Hotel Rosa dos Ventos, in Teresópolis, Brazil (fig. 1). Over the past four decades, the Wenner-Gren Foundation has had an interest in all aspects of the anthropology of human health. Earlier symposia addressed, for example, the relationships between traditional and modern medicine (Leslie 1976), diseases in populations in transition (Swedlund and Armelagos 1990), the anthropological analysis in medical anthropology (Lindenbaum and Lock 1993), and the politics of reproduction (Rapp and Ginsburg 1995). Other symposia concentrated on emerging challenges and developments such as HIV/AIDS (Herdt and Lindenbaum 1992), the Human Genome Diversity Project and other new developments in genetics (Goodman, Heath, and Lindee 2003), and modern plagues and epidemics (Herring and Swedlund 2010). Potentiality and Humanness follows in this tradition through its focus on modern developments in all aspects of the life sciences, medical practice, and related policy that impinge on humans at the genetic, cellular, individual, and population levels. The overriding question is what it means to be human in an age where biological and medical interventions once considered impossible are now possible. How do the miracles of modern science affect people living in societies as diverse as China, Vietnam, Brazil, Denmark, Sri Lanka, India, the United States, and the United Kingdom? And what can

Corporate Lives: New Perspectives on the Social Life of the Corporate Form

Corporate Lives: New Perspectives on the Social Life of the Corporate Form is the third Wenner-Gren Symposium to be published as an open-access supplement of Current Anthropology (CA). This supplementary issue is based on a symposium of the same name that was jointly sponsored by the foundation and the School for Advanced Research (SAR) and was held on the SAR campus in Santa Fe, New Mexico, August 21– 27, 2008 (fig. 1). The symposium was organized by Damani J. Partridge (University of Michigan), Marina Welker (Cornell University), and Rebecca Hardin (University of Michigan), who are also the guest editors for this issue. All three are younger scholars who are at the forefront of the emerging field of corporate anthropology. Corporations are described in the guest editors’ introduction to this supplementary issue (Welker, Partridge, and Hardin 2011) as one of the dominant institutions of our time. Corporations simultaneously shape and are shaped by humans at all levels of society and in sometimes surprising contexts. The relevance of corporations to modern life was accentuated for the symposium participants by the economic crisis that unfolded in 2008 at the time of the “Corporate Lives” meeting. Although the symposium was planned well in advance of this crisis, this serendipitous convergence brought home to all participants the relevance of the meeting and the importance of anthropology to the study and analysis of all aspects of the corporate experience. As a major result of the meeting, the guest editors advocate for “fresh anthropological research into the nature of the corporate form and the experiments in social organization it opens up, the material and symbolic power of corporations over human and environmental life, how countermovements to capitalism are reshaping the corporate ethics and governance, and the contested internal nature of corporations” (Welker, Partridge, and Hardin 2011). The “Corporative Lives” symposium was an innovative

Working Memory and the Evolution of Modern Thinking

Leslie C. Aiello is President of the Wenner-Gren Foundation for Anthropological Research (470 Park Avenue South, 8th Floor North, New York, New York 10016, U.S.A.). 1. The numbering system began with the first symposium held at Burg Wartenstein Castle in 1958 (the “International Symposium on Current Anthropology” organized by Sol Tax). During the castle years only those symposia actually held at the castle were numbered. After the sale of the castle in 1980, the symposia held elsewhere continued the numbered sequence. There were 31 nonnumbered symposia held between 1952 and 1986. “Working Memory and the Evolution of Modern Thinking” is the 139th numbered Wenner-Gren Symposium and the 168th symposium in the overall Wenner-Gren symposium series. The symposium was organized by anthropologist Thomas Wynn and psychologist Frederick Coolidge and held March 7–14, 2008, at Fortaleza do Guincho, Cascais, Portugal. Its purpose was to investigate the hypothesis that workingmemory capacity evolved over the course of human evolution and that its final enhancement in the recent past enabled the rapid expansion of modern humans at the expense of more archaic hominins. Working memory, the ability to hold information in attention and process it, has been the focus of considerable research in the cognitive sciences but has received relatively little attention among anthropologists. This symposium brought together cognitive scientists involved in the study of working memory with paleoanthropologists studying human evolution to discuss and debate issues around the evolution of working memory and its manifestation in the human evolutionary record. (Participants are shown in fig. 1.) Although there was no general agreement on the nature of working memory, there was consensus on the importance of an explicit cognitive theory such as working memory to generate appropriate tests of cognitive development. For example, all agreed on the importance of expanding the archaeological evidence of modern human cognition from, say, the presence of blades or personal ornamentation to features such as hafting, complex sequences of tool production, remotely operated traps, and colonization of oceanic islands. This symposium builds on earlier Wenner-Gren Symposia that have explored human cognitive and behavioral evolution, including Tools, Language and Cognition in Human Evolution (Gibson and Ingold 1993) and Roots of Human Sociality: Culture, Cognition and Interaction (Enfield and Levinson 2006). The foundation also has a long history of symposia on various aspects of human and primate evolution including, among many others, Social Life of Early Man (Washburn 1961), Background to Evolution in Africa (Bishop and Clark 1967), Earliest Man and Environments in the Lake Rudolf Basin (Coppens et al. 1976), and Phylogeny of the Primates: A Multidisciplinary Approach (Luckett and Szalay 1975).