Analyzing Adaptive Strategies: Human Behavioral Ecology at Twenty-Five

Human behavioral ecology (HBE) began in the mid-1970s with the application of optimal foraging models to hunter-gatherer decisions concerning resource selection and land use. In the 25 years since, the field has developed and successfully adapted evolutionary ecology theory and methods to a wide range of topics important to archaeology and to anthropology generally. In this review we examine the basic theory and its extensions to children’s foraging, conservation biology, demographic transitions, domestication and agricultural origins, the evolution of menopause, field processing and central place foraging, life history, male-female division of labor, mating tactics and fertility decisions, and resource intensification. Work on resource acquisition continues, but has been extended from foragers to pastoral and agricultural production systems. Studies of resource distribution, and especially intragroup processes of resource competition and transfers, now supplement and enrich those of resource production. Demographic and life history analyses have begun to show how ecological factors of production and distribution relate to those of mortality, fertility, and life course. Besides providing a comprehensive view of the field, we hope to demonstrate that HBE has established itself as a progressive research tradition,1 a question we take up in our conclusion. We note that this review supplements others. Two edited collections summarized the state of HBE in the early 1980s2 and early 1990s;3 shorter reviews have appeared as well.4–6 A pending collection carries us to the late 1990s.7 Reviews of HBE generally,8,9 as well as life history and demography,10–12 maturation,13 primate life span and litter size,14 mating strategies,15,16 reproductive ecology,17,18 resource transfers,19 resource conservation,20 and division of labor21 have appeared previously in this Journal. Evolutionary ecology studies “evolution and adaptive design in ecological context.”22 As a distinct field, evolutionary ecology emerged in the 1960s with the work of Charnov and Orians,23 Hutchinson,24,25 Lack,26 MacArthur and Pianka,27 MacArthur and Levins,28 MacArthur,29 Orians,30,31 and others. Textbooks on evolutionary ecology appeared in the 1970s, covering topics from the structural and behavioral traits of organisms to the organization of ecological communities. Evolutionary ecology shares fuzzy boundaries with evolutionary genetics, community ecology, animal behavior, and decision theory. When applied to the analysis of behavior, evolutionary ecology is conventionally termed “behavioral ecology.” Behavioral analyses have been an integral element of evolutionary ecology from the beginning, treating topics such as foraging strategies,27 mating systems,30 and spatial organization and competition.32 The first textbooks on behavioral ecology appeared in late 1970s33 and early 1980s.34 There now is a voluminous literature, including monograph series, dedicated journals (e.g., Evolutionary Ecology, and Behavioral Ecology and Sociobiology), and a widely read, state-of-theart series of volumes,35–38 each edition with a new set of papers. Human behavioral ecology applies evolutionary ecology models and concepts to the study of human behavioral diversity. HBE began in the mid1970s with a small set of interpretive papers39–41 and independent dissertation projects. Initially centered on foraging theory and hunter-gatherer studies, HBE has expanded over the last 25 years to encompass diverse topics and subsistence systems (Fig. 1). Although a second generation of HBE researchers is now in academic positions, the field is young enough that its initiators remain the majority of those publishing in it. HBE’s early goals were to set the cultural ecology of Steward,42 particularly as developed in his hunter-gatherer work43 and as represented in later studies such as those by Lee,44 on a sounder theoretical footing by allying it to emerging, neo-Darwinian approaches to behavior. From the start, the proposed alliance was a somewhat wary and selective one. To varying degrees, there were attempts to distance this anthropological effort (sometimes termed “socioecology”2) from the sociobiology of Wilson,45 and Bruce Winterhalder is Professor of Anthropology and Chair of the Curriculum in Ecology at University of North Carolina, Chapel Hill. He currently is working on a booklength analysis of the microecological bases of the hunter-gatherer mode of production. E-mail: [email protected] Eric Alden Smith is Professor of Anthropology and Director of the Graduate Program in Environmental Anthropology at University of Washington, Seattle. He is currently engaged in studies of marine foraging, reproductive strategies, and social status among Torres Strait Islanders in collaboration with Rebecca Bliege Bird and Douglas W. Bird. E-mail: [email protected]