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© 2018 Springer Science+Business Media, LLC, part of Springer Nature While archaeologists now have demonstrated that barter and trade of material commodities began in prehistory, theoretical efforts to explain these findings are just beginning. We adapt the central place foraging model from behavioral ecology and the missing-market model from development economics to investigate conditions favoring the origins of household-level production for barter and trade in premodern economies. Interhousehold exchange is constrained by production, travel and transportation, and transaction costs; however, we predict that barter and trade become more likely as the number and effect of the following factors grow in importance: (1) local environmental heterogeneity differentiates households by production advantages; (2) preexisting social mechanisms minimize transaction costs; (3) commodities have low demand elasticity; (4) family size, gender role differentiation, or seasonal restrictions on household production lessen opportunity costs to participate in exchange; (5) travel and transportation costs are low; and (6) exchange opportunities entail commodities that also can function as money. Population density is not a direct cause of exchange but is implicated inasmuch as most of the factors we identify as causal at the household level become more salient as population density increases. We review archaeological, ethnohistoric, and ethnographic evidence for premodern marketing, observing that the model assumptions, variables, and predictions generally receive preliminary support. Overall, we argue that case study and comparative investigation of the origins of marketing will benefit from explicit modeling within the framework of evolutionary anthropology.

Active search for prey is energetically costly, so understanding how foragers optimize search has been central to foraging theory. Some theoretical work has suggested that foragers of randomly distributed prey should search using Lévy flights, while work on area-restricted and intermittent search strategies has demonstrated that foragers can use the information provided by prey encounters to more effectively adapt search direction and velocity. Previous empirical comparisons of these search modes have tended to rely on distribution-level analyses, due to the difficulty of collecting event-level data on encounters linked to the GPS tracks of foragers. Here we use a preliminary event-level data-set (18.7 hours of encounter-annotated focal follows over 6 trips) to show that two Colombian blowgun hunters use adaptive encounter-conditional heuristics, not non-conditional Lévy flights, when searching for prey. Using a theoretically derived Bayesian model, we estimate changes in turning-angle and search velocity as a function of encounters with prey at lagged time-steps, and find that: 1) hunters increase average turning-angle in response to encounters, producing a more tortuous search of patches of higher prey density, but adopt more efficient uni-directional, inter-patch movement after failing to encounter prey over a sufficient period of time; and, 2) hunters reduce search velocity in response to encounters, causing them to spend more of their search time in patches with demonstrably higher prey density. These results illustrate the importance of using event-level data to contrast encounter-conditional, area-restricted search and Lévy flights in explaining the search behavior of humans and other organisms.

Analyses of racial disparities in police use-of-force against unarmed individuals are central to public policy interventions; however, recent studies have come to apparently paradoxical findings concerning the existence and form of such disparities. Although anti-black racial disparities in U.S. police shootings have been consistently documented at the population level, new work has suggested that racial disparities in encounter-conditional use of lethal force by police are reversed relative to expectations, with police being more likely to: (1) shoot white relative to black individuals, and (2) use non-lethal as opposed to lethal force on black relative to white individuals. Encounter- and use-of-force-conditional results, however, can be misleading if the rates with which police encounter and use non-lethal force vary across officers and depend on suspect race. We find that all currently described empirical patterns in the structuring of police use-of-force—including the “reversed” racial disparities in encounter-conditional use of lethal force—are explainable under a generative model in which there are consistent and systemic biases against black individuals. If even a small subset of police more frequently encounter and use non-lethal force against black individuals than white individuals, then analyses of pooled encounter-conditional data can fail to correctly detect racial disparities in the use of lethal force. In more technical terms, statistical assessments of racial disparities conditioned on problematic intermediate variables, such as encounters, which might themselves be a causal outcome of racial bias, can produce misleading inferences. Population-level measures of use-of-force by police are more robust indicators of the overall severity of racial disparities than encounter-conditional measures—since the later neglect the differential morbidity and mortality arising from differential encounter rates. As such, population-level measures should be used when evaluating the local-level public health implications of racial disparities in police use-of-force. Research on encounter-conditional use-of-force by police can also fruitfully contribute to public policy discussions, since population-level measures alone cannot address whether racial disparities are driven by disparities in encounters or disparities in use-of-force conditional on encounters. Tests for racial biases in the encounter-conditional use of lethal force, however, must account for individual-level variation across officers in terms of race-specific encounter rates or risk falling to Simpson’s paradox.

The sub-section 2.1 of the Supplementary Information file in the original article was incorrect. This whole sub-section has now been removed.

Author(s): Ross, Cody T; Mulder, Monique Borgerhoff; Oh, Seung-Yun; Bowles, Samuel; Beheim, Bret; Bunce, John; Caudell, Mark; Clark, Gregory; Colleran, Heidi; Cortez, Carmen; Draper, Patricia; Greaves, Russell D; Gurven, Michael; Headland, Thomas; Headland, Janet; Hill, Kim; Hewlett, Barry; Kaplan, Hillard S; Koster, Jeremy; Kramer, Karen; Marlowe, Frank; McElreath, Richard; Nolin, David; Quinlan, Marsha; Quinlan, Robert; Revilla-Minaya, Caissa; Scelza, Brooke; Schacht, Ryan; Shenk, Mary; Uehara, Ray; Voland, Eckart; Willfuhr, Kai; Winterhalder, Bruce; Ziker, John | Abstract: With apologies, an incorrect author list was given in the article. An additional author, Chris von Rueden, (Jepson School of Leadership Studies, University of Richmond) also contributed to this work. Author Ryan Schacht's affiliation was out-of-date. His correct affiliation is: Department of Anthropology, East Carolina University.

Journal of Anthropological Archaeology 45 (2017) 53–68 Contents lists available at ScienceDirect Journal of Anthropological Archaeology journal homepage: www.elsevier.com/locate/jaa The Classic Period Maya transition from an ideal free to an ideal despotic settlement system at the polity of Uxbenka Keith M. Prufer a, ⇑ , Amy E. Thompson a , Clayton R. Meredith a , Brendan J. Culleton b , Jillian M. Jordan a , Claire E. Ebert b , Bruce Winterhalder c , Douglas J. Kennett b a b c Department of Anthropology, University of New Mexico, United States Department of Anthropology, The Pennsylvania State University, United States Department of Anthropology, University of California-Davis, United States 1. Introduction More than eleven hundred years of settlement history at Uxbenka, a Classic Period Maya polity (ca. 300 BC to AD 900) located in southern Belize (Fig. 1), conform to a patterned shift from an ideal free to a despotic distribution, coincident with a change toward habitat suitability increasingly dependent on anthropogenic features of the landscape. To demonstrate this claim, we document the development and geospatial organization of the settlement systems at Uxbenka using differential GPS and LiDAR data associated with extensive survey and excavations (Prufer et al., 2015). We also chronicle the development of the built landscape; a major trade corridor, neighborhoods, districts, and the ceremonial center being the prime features under consideration. Finally, we assess the relationships between the spatial patterns as populations in-fill to political developments within the frame- work of two population ecology models: the Ideal Free Distribution (IFD) and Ideal Despotic Distribution (IDD). 1.1. Setting, objectives and questions Uxbenka (Fig. 1) was a moderately sized Maya center during the Classic Period (AD 250–900), comparable to nearby sites such as Pusilha and Lubaantun but small when compared to the major cen- ters of Tikal and Caracol to the northwest. Since 2005 the Uxbenka Archaeological Project (UAP) has conducted extensive survey and excavations in the settlement zone surrounding Uxbenka, with a focus on building a precise absolute chronology for the develop- ment of the community and its environmental context (Culleton et al., 2012; Prufer et al., 2011, 2015; Prufer and Thompson, 2016). Cultural ecological studies conducted in parallel are docu- menting the agro-ecology of contemporary subsistence tactics in the nearby community of Santa Cruz (Baines, 2015; Culleton, 2012). We draw on both sources of information in our analysis. In agrarian communities, residential settlements are the pri- mary social unit and location of human interactions that articulate with broader economic and political processes (Ashmore, 1981; ⇑ Corresponding author. E-mail address: kmp@unm.edu (K.M. Prufer). http://dx.doi.org/10.1016/j.jaa.2016.11.003 0278-4165/Published by Elsevier Inc. Willey, 1968). Despite their importance they remain understudied and poorly dated in the Maya area (See Supplement S-1). For instance, little research has examined the precise chronological histories of settlements surrounding Classic Period Maya centers. This leaves us unable to answer basic anthropological questions: Why were people more successful in some locations compared to others on a landscape? How did population growth, the natural environment, and the built environment influence status dispari- ties of settlements through time? What are the relationships between settlements, which generate agricultural and other resources, and the consolidation and differential control of those resources by emerging political elites? We explore fundamental questions in the development of set- tlement systems in the Maya Lowlands and beyond: What organiz- ing principles and socio-environmental factors guide residential settlement decisions in agricultural societies when the environ- ment is an open access frontier? How do these initial choices change with the growth and development of low-density urban environments? And, what are the long-term consequences of these initially open but increasingly constrained settlement options? We identify and assess the relative importance of social and environ- mental variables that may have been important to human decision-making in a bounded, community-centered landscape. Furthermore, we examine how those decisions were reflected in the relative success of residential compounds over centuries of growth. In pursuit of answers to these and related questions, we (a) pre- sent a high precision AMS 14 C chronology for the development of the Uxbenka settlement system; (b) identify and describe neigh- borhoods (loci of daily household interactions) and districts (local seats of power and authority) as organizing principles for the dis- tribution of households and local economic and political control across the landscape; (c) develop population estimates and a model of demographic growth; (d) analyze factors affecting deci- sions about household location; and (e) offer an evolutionary anthropology model, drawing on behavioral ecology, to help explain why some households and neighborhoods were larger, longer-occupied, and apparently more successful over the 1150 year occupation of the polity. Our evidence and interpreta- tion together document an increasingly stratified relationship

© 2017 Elsevier Ltd and INQUA. Changes in social organization accelerated on California's northern Channel Islands beginning around 1300 cal BP. These changes were associated with shifts in settlement and subsistence patterns related in part to drought conditions during the Medieval Climatic Anomaly (MCA; 1150-600 cal BP). By the end of the MCA, settlement patterns demonstrate evidence for territoriality and can be described by the ideal despotic distribution. The occupants of the most productive habitats prevented new settlers from moving in and accessing the available resources. We use faunal data from five sites on western Santa Rosa Island (CA-SRI-15, -31, -97, -313, and -333) to trace changes in settlement and population aggregation through this period. Fishing, which can support higher population densities than harvesting shellfish, increased overall from the Middle (2550-800 cal BP) to Late Period (650-168 cal BP), but there were fewer settlement sites on western Santa Rosa Island. In the centuries before the Middle to Late Period Transition (MLT; 800-650 cal BP), people occupied sites geographically dispersed along the west coast of the island. After the MLT, fishing was restricted to fewer large coastal villages. We argue that environmental stress and an increase in warfare on the northern Channel Islands drove the growth of more permanent consolidated villages, the development of territoriality, and settlement patterns consistent with greater resource defense and therefore a more despotic distribution.

© 2016 Elsevier Inc. Evolutionary ecological models of human fertility predict that: (1) parents will bias investment toward the sex with the highest fitness prospects in a particular socio-ecological context; (2) fertility is subject to quantity–quality trade-offs; and (3) fertility decisions will be sensitive to both predictable and stochastic mortality risk and the relative fitness value of differently sized sib-sets (the variance compensation hypothesis). We test these predictions using demographic records from the Agta, an indigenous population from the Philippines, who, as a result of disruption by loggers, miners, and settlers, are undergoing a demographic and social/ecological transition from foragers to peasant laborers. Leveraging the spatial and temporal variation in the Agta Demographic Database, we conduct an analysis of Agta life-history traits across this transition. Specifically, we compare the Casiguran Agta (CA) with the more isolated peninsular San Ildefonso Agta (SIA) sub-population from before (phase 1) and after (phase 2) encroachment. We find: (1) evidence of a decline in overall survival from phase 1 to phase 2, coupled with increased parental investment in first-born daughters compared to first-born sons in the CA population, and increased parental investment in sons versus daughters in the SIA population; (2) evidence of a moderate quantity–quality trade-off in CA and SIA fertility in phase 1; and (3) support for predictions of the variance compensation hypothesis as a driver of the lowered relative fertility in the CA. Our customized methods, comparative framework, and simultaneous focus on fertility and mortality allow us to show how heterogeneity in mortality and fertility are linked to life history trade-offs and environmental context in a manner consistent with the predictions of evolutionary ecological models.

This paper has three goals:()) to define the anthropological subfield of human behavioral ecology (HBE) and characterize recent progress in this research tradition; (2) to address Joseph's (2000) critique of HBE from the perspective of an advocate of that field; € and (3) to suggest features that make for effective criticism of research traditions. (1) HBE attempts to understand intra- and inter-societal diversity in human behavior as the product of species-wide adaptive goals which must be realized in highly diverse, socio-environmental circum- stances. Theoretically, HBE draws selectively from neo-Darwinism and its cultural-evolutionary analogs, from micro-economics, and from elements of formal decision and game theory. Applications generally use simple, formal models as heuristic devices for generating testable hypotheses about resource use, reproductive and social behavior, and life history traits. (2) Using Kuhn's (1977) and McMullin's (1983) criteria for assessing progress in a research tradition, I examine Joseph's review of HBE, indicating the several points on which we agree and the greater number for which I believe her criticisms are misplaced or in error. (3) Finally, I try to describe general features of effective critique, in the sense of critical commentary that enables the advance of scientific understanding through collective scholarly effort. Such criticism will be necessary if we are to sort out the relative strengths and potential contributions of the several research traditions in human ecology (e.g., cultural ecology, historical ecology, political ecology, etc.).

Risk-sensitive analysis of subsistence adaptations is warranted when (i) outcomes are to some degree unpredictable and (ii) they have nonlinear consequences for fitness and/or utility. Both conditions are likely to be common among peoples studied by ecological anthropologists and archaeologists. We develop a general conceptual model of risk. We then review and summarize the extensive empirical literatures from biology and anthropology for methodological insights and for their comparative potential. Risk-sensitive adaptive tactics are diverse and they are taxonomically widespread. However, the anthropological literature rarely makes use of formal models of risk-sensitive adaptation, while the biological literature lacks naturalistic observations of risk-sensitive behavior. Both anthropology and biology could benefit from greater interdisciplinary exchange. © 1999 Plenum Publishing Corporation.

Behavioral ecologists combine evolutionary models of mechanism and ecological models of circumstance to analyze the origins and forms of intragroup exchange among social foragers, a category that includes primates, hominids, and recent and modem hunter-gatherers. Evolutionary mechanisms encompass individual, sexual, reciprocal, kin, group, and cultural selection; models of circumstance include tolerated theft, scrounging, marginal value, trade, show-offs, and risk reduction. After a critical review, I develop a partial synthesis of these models. The results show that exchange behaviors have multicausal origins and they likely will be diverse due to differing combinations of mechanism and circumstance. They also help explain seemingly unique features of foraging economies, including constrained production and routine demand sharing. © 1997 Plenum Publishing Corporation.

Using marginal analysis to represent Blurton Jones's concept of tolerated theft, I show how equilibrium resource transfers among individuals might be affected by foraging behavior, resource qualities, and number of participants. The model applies to hominids and other species that exchange or share food or other resources. Among the results: Tolerated theft enhances the value to be derived from resources, packets intermediate in size are most likely to be subjected to tolerated theft, packet division is more likely to be unequal than equal, division is a function of group size, and tolerated theft is most likely in small groups. The model also suggests that among redprocators the widest possible exchange or sharing is in the self-interest of the individual procuring the resource. In general, evolutionary cost-benefit accounting should track marginal changes in the value (fitness or utility) of resources. Marginal valuation is conceptually primary and may produce results that differ from direct measures of quantity. © Elsevier Science Inc., 1996.

Two chimpanzees stalk, isolate, and kill a red colobus monkey. An attendant primatologist notes that parts of the prey are relinquished selectively to onlooking scroungers (Fig. 1). A human forager returns to camp mid-afternoon with a freshly killed, medium-sized ungulate. Later in the day, an ethnographer observes that shared portions of the animal have found their way into the cooking pots of most or all of those in the small band. Examining a prehistoric scatter of food residues, an ethnoarcheologist wonders when early hominids began to scrounge or share food, and with what consequences for our evolution. All of these settings represent one problem: the analysis of intragroup resource transfers among social foragers. New studies in the behavioral ecology of transfers show them to be more commonplace in nature, more complicated and variable, and more subject to comparative analysis than has been appreciated.

Anthropological views on the labour effort required of hunter-gatherers have flip-flopped between stereotypic positions depicting either very limited subsistence work or long exertion. A computer simulation using evolutionary and population ecology models shows that at equilibrium foraging efficiency is a declining function of work effort, whereas population density responds to work effort by first increasing and then decreasing. This and other foraging theory models provide a framework which can explain observations of routine sharing, modest effort and limited material accumulation in hunter-gatherer societies, leads us to expect diversity in the expression of these characteristics and, is consistent with neo-Darwinian and neoclassical economic theory. Evolutionary ecology theory thus obviates the need for a "Zen' economics as proposed by Sahlins. -from Author

The present paper examines the use of dung for two essential human resources, fuel and fertilizer, in a highland community of southern Peru. The limited energy availability and the poor soils of the region, primarily the result of high-altitude climate and topography, necessitate this practice. Alternatives to dung use are costly or unavailable. Grazing herbivores transform the widely dispersed puna grasses into a compact and easily gathered source of energy and nutrients. Native choice among available dungs corresponds to their qualities: sheep dung, richest in nutrients, is applied as fertilizer; llama and cattle dungs, each with a high caloric value, are burned as fuels. Dung use is interpreted as an energetically efficient response to the highland environment and as central to the subsistence pattern in the area. © 1974 Plenum Publishing Corporation.

This chapter analyzes the climate, landscape, flora, and fauna of the boreal forest in northern Ontario. It emphasizes facets of this ecosystem known to be of importance to humans. Its goal is to establish the context—the mix of physical and biotic factors, some patterned and some irregular in occurrence—in which human adaptation occurs. The boreal forest on first acquaintance can be deceptive. To the passing outsider it is nearly flat, without the vistas that give a landscape an immediate character. Its streams are mostly sluggish, its vegetation diminutive. It feigns monotony over space and time. Yet ecologically it is a habitat vibrant with activity. Although without strong relief, the landscape is strongly differentiated. The populations of plants and animals of the forest interact in a highly dynamic fashion. This chapter describes the forest in ways that illuminate that differentiation and activity, and attempts to capture its meaning as the context of the adaptation studies which make up the remainder of this volume (see also Kryuchkov, 1976; Pruitt, 1978; Winterhalder, 1977).

Our objectives in this final chapter are to consolidate our observations on one major piece of unfinished business—cold adaptation—and to describe the pattern of general adaptation which we have observed in our studies in boreal anthropology.

Author(s): Winterhalder, B | Abstract: Fossil evidence from the Plio‐Pleistocene of Africa apparently has confirmed a multi‐lineage interpretation of early hominid evolution. Empirical refutation of the single species hypothesis must now be matched to the evolutionary ecology theory, which can underwrite taxonomic assessment and help to explain sympatric hominid coexistence. This paper contributes to that goal by reassessing the ecological rationale provided for the single‐species hypothesis. Limiting similarity concepts indicate that the allowable ecological overlap between sympatric competitors is greater than the degrees of metric overlap often advanced as standards for identifying fossil species. Optimal foraging theory and the compression hypothesis show that the initial ecological reaction of a hominid to a sympatric competitor would likely be micro‐habitat divergence and possibly also temporal differentiation of resource use. The long‐term, evolutionary response is niche divergence, probably involving diet as well. General niche partitioning studies suggest that diet and habitat are the most common dimensions of niche separation, although temporal separation is unusually frequent in carnivores. The equation of niche with culture, basic to the single‐species hypothesis, has no analytic meaning. Finally, four minor points are discussed, suggesting that (a) extinction is not unlikely, even for a long‐lived and competitively competent hominid lineage, (b)parsimony is fickle, (c)interspecific mutualism may jeopardize survival, and (d)generalists are subordinate competitors, but for hominids, seemingly, successful ones. I argue that analog models of hominid paleoecology should be replaced by the use of zoological and anthropological observations to assess the generality and reliability of ecological theory and comcepts that may encompass early hominids. Copyright © 1981 Wiley‐Liss, Inc., A Wiley Company

Human evolution and ecology analyses argue that environment is a major factor influencing biological and sociocultural adaptation, but they rarely analyze environmental properties. Multiple problems of perspective and method can arise from the normative and nondynamic environmental descriptions which pervade these analyses. This paper examines human adaptation frameworks to identify theoretical guidelines for environmental description in ways appropriate to available theories of biocultural evolution or congruent with known ecosystem qualities. Concepts and terminology are given for describing the spatial and temporal properties characteristic of ecosystems and central to hypotheses about ecological adaptation. These include: patchiness and grain; stability and resilience; persistence and recurrence; and predictability, constancy, and contingency. Field experience, theory, and the qualities of ecosystems themselves suggest that detailed, historical (long-term) environmental analysis is necessary to determine the role of ecological factors in human evolution and adapation. © 1980 Plenum Publishing Corporation.

Optimal foraging theory is that part of evolutionary ecology developed over the last two decades as a tool for analyzing animal subsistence behavior (Pyke et al. 1977; Krebs 1978). A collection of articles (Winterhalder and Smith 1981) that gives foraging models a central role in the analysis of archeological and ethnographic data on hunter-gatherers is the subject of a lengthy review by John Martin ("Optimal Foraging Theory: A Review of Some Models and Their Applications," AA 85:612-629, 1983). As editors of this volume (Hunter-Gatherer Foraging Strategies, hereafter, HGFS), we wish to note some of the serious flaws in Martin's piece. Along with its demonstrated heuristic value, there are some genuine difficulties in optimal foraging theory (review in Krebs et al. 1983) and limitations on its applicability to humans (reviews in Smith 1983; Winterhalder 1983). Some of these are known; we presume that some are unrecognized. One of the central virtues of foraging theory is that it provides a coherent set of concepts and models that can be subjected to criticism, debate, and revision. However, the criticisms should be informed, the debate rigorous, and the proposed revisions carefully constructed to ensure that they truly offer improvements in clarity, scope, or anthropological utility. Because Martin's review fails by these criteria, a critique is in order. A careful response to a 10,000-word essay packed with technical commentary would involve a critique of at least equal length, especially since Martin has misunderstood or misinterpreted fundamental aspects of evolutionary ecology and foraging theory. The editorial policy of this journal severely restricts the length of replies, so here we simply list Martin's more serious errors and briefly discuss two of them. Readers interested in the fuller

Foraging models can predict the optimal diet selection for an organism which has the goal of maximizing its net acquisition rate for energy while hunting and gathering. Here a simulation methodology is used to determine the optimal diet selection under the assumption that the forager's goal is to minimize the risk of an energy shortfall. The results show that the rate-maximizing and risk-minimizing diets are similar; that sharing is more effective than changes in diet in reducing risk; and that the risk-reduction which can be obtained from sharing requires quite small numbers of participants. Food sharing may be an ancient and pervasive feature of hominid foraging adaptations.

In 1974–1976, in the book Zoonomia or the Laws of Organic Life, Erasmus Darwin (1794) speculated that modification of species was brought about through the satisfaction of three wants. He identified them with admirable directness as “lust, hunger, and danger.” In the more prosaic but parallel terminology of contemporary evolutionary ecology these have become mating, foraging and the avoidance of predators (and I would add hazards). The list is still meant to be inclusive, and to represent separable arenas of adaptive or fitness-enhancing behavior, each subject to somewhat different types of investigation. Other chapters in this volume cover the mating and demographic systems and the responses to climate, physical hazards, and the dangers from predation of native peoples living in the boreal forest of northern Ontario. Adjustments by residents to the effective environment of this region are described and analyzed as adaptations. In this chapter I add an analysis relevant to E. Darwin’s second category, hunger. In language more appropriate to the time, it is a study of foraging behavior.

In this paper we combine foraging theory and population biology models to simulate dynamic relationships between hunter-gatherers and their prey resources. Hunter-gatherer population growth responds to the net marginal rate of foraging; prey population growth responds logistically to exploitation. Thus conceived, the relationship between forager and prey biomass is time-dependent and nonlinear. It changes from stable equilibrium to damped and stable cycles with modest adjustments of input parameters. And, it produces the largest sustainable human population at intermediate levels of individual work effort. At equilibrium the forager takes all prey types with a pursuit and handling rate greater than or equal to its maintenance foraging rate. The structural properties of the model compel us to reject standard anthropological interpretations of the carrying capacity concept; they provide new insights on old issues such as original affluence and intensification. Analysis of the interaction of human population, diet selection, and resource depletion requires microecological models in part because the relevant processes occur on time scales largely invisible to both ethnography and archaeology.