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Interactions between humans, animals, and the environment facilitate zoonotic spillover—the transmission of pathogens from animals to humans. Narratives that cast modern humans as exogenous and disruptive forces that encroach upon "natural" disease systems limit our understanding of human drivers of disease. This review leverages theory from evolutionary anthropology that situates humans as functional components of disease ecologies, to argue that human adaptive strategies to resource acquisition shape predictable patterns of high‐risk human–animal interactions, (2) humans construct ecological processes that facilitate spillover, and (3) contemporary patterns of epidemiological risk are emergent properties of interactions between human foraging ecology and niche construction. In turn, disease ecology serves as an important vehicle to link what some cast as opposing bodies of theory in human ecology. Disease control measures should consider human drivers of disease as rational, adaptive, and dynamic and capitalize on our capacity to influence ecological processes to mitigate risk. [ABSTRACT FROM AUTHOR]

This study uses a simulation model to explore the causes of ‘extreme civil heroism’: risking one’s life to help a stranger. The model uses a mixture of traditional economic thinking (based on rational self-interest) and human behavioral ecology (based on natural selection). Simulated agents choose between two competing communities (one with heroism and one without) by maximizing expected utility. Which community thrives is observed. Labor productivity, risk tolerance, perspectives on death, emergency response training and accident probability are analyzed as drivers of heroic community success. A preliminary assessment of the model is conducted using data from Eastern Europe. Avenues for future research are described.

The Early Holocene is a critical period in the American Southeast and represents the time between the end of the Pleistocene and emerging cultural complexity of the Mid-Holocene. Due to the limitations imposed by a relative lack of site preservation, an important avenue of inquiry for understanding this period has been connecting the few reported, well-dated sites with the distribution of surface finds to explore how people organized their mobility across landscapes. The most widely cited examples of studies examining Early Holocene landscape use in the region are Anderson and Hanson (1988), Daniel (2001), and Hollenbach (2009). In this article, we discuss the historical development of these three approaches to modeling landscape use and explore the impacts of these works in Southeastern archaeology. Finally, we introduce four articles that explore the applicability of these three approaches in Virginia (Gingerich, this issue), Florida (Halligan et al., this issue), the lower Ohio River valley (Jennings et al. this issue), and the upper Tombigbee River valley (Strawn et al., this issue). [ABSTRACT FROM AUTHOR]

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.

In this study, we sought to examine firewood use patterns in artisanal ceramic production by a quilombola community in the context of forest scarcity in Northeastern Brazil. This article aimed to answer the following questions: (1) Is the firing of ceramic products related to the perceived quality, diversity, or plant part used as firewood? (2) Does the diversity of plants used as firewood vary according to the age and gender of artisan potters? (3) What are the physical and energetic properties of the species most commonly used as firewood? Our main findings were that resource availability and accessibility seem to be the determining factors of firewood use. Exotic species were widely used. Variables commonly described as predictors of firewood diversity, such as age and gender, were not relevant in the context of forest scarcity. The most used exotic species have good physicochemical properties and can be a viable alternative to meet the firewood demand of ceramic production. However, the results showed that these species are more readily available to potters who have access to private woodlands. Therefore, in the studied context, we suggest the need for conservation strategies that foster the creation of energy forests composed of exotic species and, in parallel, promote conservation and reforestation actions aimed at native species. [ABSTRACT FROM AUTHOR]

Monogamy appears to have become the predominant human mating system with the emergence of highly unequal agricultural populations that replaced relatively egalitarian horticultural populations, challenging the conventional idea-based on the polygyny threshold model-that polygyny should be positively associated with wealth inequality. To address this polygyny paradox, we generalize the standard polygyny threshold model to a mutual mate choice model predicting the fraction of women married polygynously. We then demonstrate two conditions that are jointly sufficient to make monogamy the predominant marriage form, even in highly unequal societies. We assess if these conditions are satisfied using individual-level data from 29 human populations. Our analysis shows that with the shift to stratified agricultural economies: (i) the population frequency of relatively poor individuals increased, increasing wealth inequality, but decreasing the frequency of individuals with sufficient wealth to secure polygynous marriage, and (ii) diminishing marginal fitness returns to additional wives prevent extremely wealthy men from obtaining as many wives as their relative wealth would otherwise predict. These conditions jointly lead to a high population-level frequency of monogamy.

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.

This paper offers a new numerical approach to model the effects of archaeological site placement and population density on environmental suitability using two ecological models, the Ideal Free Distribution (IFD) and Ideal Despotic Distribution (IDD), treating the Oued Loukkos in northern Morocco as an example. This method incorporates local resource depletion with increasing population density consistent with the predictions of the IFD. It also incorporates the potential for the exclusion of part of the population from certain productive areas consistent with the IDD. In this study, we propose a dynamic approach to the impact of site placement on habitat suitability and therefore broader application for understanding changes in settlement distribution with population density through time. Furthermore, resulting settlements can be parameterized by a Zipf-Mandelbrot distribution, entailing a direct relationship between the ecological, demographic, and political factors and the resulting rank-size distribution of sites. This approach allows for a broader range of applications among foraging and agricultural economies. [ABSTRACT FROM AUTHOR]

This study employs an ideal free distribution (IFD) model to conduct a fine-grained analysis of environmental factors affecting the pre-Columbian colonisation sequence and settlement patterning in the southern Lesser Antilles of the Eastern Caribbean. We compiled a database of all known archaeological site locations and associated chronological data from St. Vincent, the Grenadines, and Grenada, and vetted this dataset for accuracy. We then performed multivariate statistical analysis of the vetted site data and 24 environmental variables hypothesised to influence settlement habitat quality, including soil attributes, proximity to freshwater/stream beds, structure and sizes of marine environments, and net primary productivity (NPP) layers. Iterative testing and refinement of the model allowed for the creation of a predictive map of pre-Columbian archaeological sites over time. Results indicate proximity to freshwater wetlands, NPP, and reef size were important variables influencing habitat choice. Additionally, latitude (distance from the equator) was also a significant variable, indicating support for a proposed colonisation of the southern Lesser Antilles that began in the northern Caribbean, rather than the south. Lastly, we provide a site inventory and map of predicted site locations that can aid in the management of threatened archaeological resources within the study region. [ABSTRACT FROM AUTHOR]

We apply the Ideal Free Distribution (IFD) and Ideal Despotic Distribution (IDD) models to two Bronze Age (ca. 3100–1050 BCE) mainland Greek regions with different local ecologies and culture histories: Messenia and the Argolid. Using existing settlement data, we show that regions within the same cultural system contemporaneously fit different settlement patterns, reflecting distinct environmental adaptations. Such differences help to understand regional variations in resource access and competition. Although the highest-ranked habitats were settled first in each region, large-scale expansion to lower-ranked habitats occurred more quickly in the Argolid, likely because highly productive agricultural land was limited, resulting in a competitive focus on the Argive Plain. This contrasts with Messenia, where access to agricultural resources is better distributed. Our results demonstrate that applying ideal distribution models at a regional scale provides valuable information about the development of social complexity and the conditions in which it occurs. [ABSTRACT FROM AUTHOR]

Explaining variation in hunter-gatherer livelihoods hinges on our ability to predict the tradeoffs and opportunities of pursuing different kinds of prey. Central to this problem is the commonly held assumption that larger animals provide higher returns upon encounter than smaller ones. However, to test this assumption, actualistic observations of hunting payoffs must be comparable across different social, technological, and ecological contexts. In this meta-analysis, we revisit published and unpublished estimates of prey return rates (n = 217 from 181 prey types) to assess, first, whether they are methodologically comparable, and second, whether they correlate with body size. We find systematic inter-study differences in how carcass yield, energetic content, and foraging returns are calculated. We correct for these inconsistencies first by calculating new estimates of energetic yield (kcals per kg live weight) and processing costs for over 300 species of terrestrial and avian game. We then recalculate on-encounter returns using a standardized formula. We find that body size is a poor predictor of on-encounter return rate, while prey characteristics and behavior, mode of procurement, and hunting technology are better predictors. Although prey body size correlates well with processing costs and edibility, relationships with pursuit time and energetic value per kilogram are relatively weak. [ABSTRACT FROM AUTHOR]

Body mass is widely recognized as a morphological trait which is important for fitness optimization both in humans and other animals. Here, we propose that body mass is a part of fast life history trajectory – the fitness optimization pattern which emerges from harsh environment with a function to maximize reproductive output. To test this prediction, we measured body mass index (BMI) and a set of life history indicators in a large sample of reproductive individuals (N = 1,504; 32% males; Mage = 27.20; SD = 9.2). The data were collected via an online survey. Bivariate correlations showed that BMI was positively related to reproductive success, childhood poverty, and short-term mating success; furthermore, it was negatively associated to physical health, age of the first menarche, and economic reasons against reproduction. The Network Analysis confirmed that BMI is positively related to short-term mating success and reproductive success, and negatively to physical health and economic reasons against reproduction. Furthermore, centrality metrics showed that BMI has relatively low centrality indices, and thus represents a peripheral node in the network. The present data confirm that body mass is a morphological trait which participates in the fast life history trajectory of fitness optimization. A body mass which is slightly higher than population mean (but below obesity levels) probably represents an adaptive response to depriving economic conditions in childhood and contributes to the maximization of reproductive fitness. Finally, we highlight that the relations between body mass and life history may differ between and within species.

Access to social capital and valued resources modulates household decision-making as people seek to occupy the best-quality patches of land available. Prior occupancy, inheritance, and land tenure norms can constrain opportunities resulting in inequality between households. We examined processes of settlement development and structural inequality at two Classic Period (250–900 CE) Maya centers, Ix Kuku'il and Uxbenká, in Southern Belize. From the lens of human behavioral ecology (HBE), we evaluate the predictions of two population density models, the ideal free distribution (IFD) and the ideal despotic distribution (IDD), on household decision-making. To do so, we correlate the initial foundation date of households with nine measurable suitability variables as proxies for social and environmental resources. We conclude that at Uxbenká and Ix Kuku'il, social resources, such as the ability to mobilize labor, cooperation, and access to a transportation corridor, likely influenced where people chose to live. Environmental resources, including good farmland and access to perennial water sources, were widely distributed across the landscape and accessible to everyone. This study highlights the importance of social relationships on household decision-making, which is often difficult to detect in the archaeological record. The development and manifestation of institutionalized inequality are processes relevant to all societies past and present. [ABSTRACT FROM AUTHOR]

Human behavioral ecology, Optimal foraging theory, Human-wildlife conflict, Depredation, Interspecific competition, Ecosystem-based management, Sustainable resource exploitation, Longline fisheries Keywords: Human behavioral ecology; Optimal foraging theory; Human-wildlife conflict; Depredation; Interspecific competition; Ecosystem-based management; Sustainable resource exploitation; Longline fisheries EN Human behavioral ecology Optimal foraging theory Human-wildlife conflict Depredation Interspecific competition Ecosystem-based management Sustainable resource exploitation Longline fisheries 649 653 5 11/11/21 20211001 NES 211001 Introduction Global expansion of the human population has shaped many of Earth's ecosystems. It is therefore curious that marine depredation has not been investigated from this standpoint, despite increasing interactions between fisheries and marine predators over the last 70 years (Gilman et al. [14]; Read [26]) that have particularly impacted the longline fishery, since baits and fish are freely accessible for marine predators. Understanding Human-Wildlife Conflict as an Interspecific Competition Using Human Behavioral Ecology. [Extracted from the article]

Over the past decade, niche construction theory (NCT) has been one of the fastest-growing theories or scholarly approaches in the social sciences, especially within archaeology. It was proposed in the biological sciences 25 years ago and is often referred to as a neglected evolutionary mechanism. Given its rapid acceptance by the archaeological community, it is important that scholars consider how it is being applied and look for discrepancies between applications of the concept. Many critical discussions of NCT have already been published, but most of them are in biology journals and may be overlooked by scholars in the social sciences. In this manuscript, my goal is to synthesis the criticisms of NCT, better allowing archaeologists to independently evaluate its usefulness. I focus on the claims of novelty and differences between NCT and other approaches to conceptualizing anthropogenic ecosystem impacts and culture-evolution feedbacks. I argue that the diverse concepts currently included in the wide-reaching purview of NCT are not new, but the terminology is and may be useful to some scholars. If proponents of the concept are able to unify their ideas, it may serve a descriptive function, but given that lack of a testable explanatory mechanism, it does not have a clear heuristic function. [ABSTRACT FROM AUTHOR]

Since despotism is a common evolutionary development in human history, we seek to understand the conditions under which it can originate, persist, and affect population trajectories. We describe a general system of population ecology equations representing the Ideal Free and Despotic Distributions for one and two habitats, one of which contains a despotic class that controls the distribution of resources. Using analytical and numerical solutions we derive the optimal concession strategy by despots with and without subordinate migration to an alternative habitat. We show that low concessions exponentially increase the time it takes for the despotic habitat to fill, and we discuss the trade-offs despots and subordinates confront at various levels of exploitation. Contrary to previous hypotheses, higher levels of despotism do not necessarily cause faster migration to alternative habitats. We further show how, during colonization, divergent population trajectories may arise if despotic systems experience Allee-type economies of scale.

We examine the relationship between niche construction theory (NCT) and human behavioral ecology (HBE), two branches of evolutionary science that are important sources of theory in archeology. We distinguish between formal models of niche construction as an evolutionary process, and uses of niche construction to refer to a kind of human behavior. Formal models from NCT examine how environmental modification can change the selection pressures that organisms face. In contrast, formal models from HBE predict behavior assuming people behave adaptively in their local setting, and can be used to predict when and why people engage in niche construction. We emphasize that HBE as a field is much broader than foraging theory and can incorporate social and cultural influences on decision‐making. We demonstrate how these approaches can be formally incorporated in a multi‐inheritance framework for evolutionary research, and argue that archeologists can best contribute to evolutionary theory by building and testing models that flexibly incorporate HBE and NCT elements. [ABSTRACT FROM AUTHOR]

The prehistoric establishment and expansion of permanent settlements on the Northern Channel Islands of southern California generally follows a pattern predicted by the population ecology model, the ideal free distribution (IFD). We determine this by comparing the abundant archaeological record of these Islands against a careful quantification of habitat suitability using areal photography, satellite imagery, and field studies. We assess watershed area, length of rocky intertidal zone, length of sandy beach for plank canoe pull-outs and area of off-shore kelp beds, for 46 coastal locations. A simple descriptive anal- ysis supports key IFD predictions. A Bayesian model fitted with the Gibbs sampler allows us to recon- struct the Native assessment of habitat that appears to underlie this process. Use of the Gibbs sampler mitigates the impact of missing data, censored variables, and uncertainty in radiocarbon dates; it allows us to predict where new settlements may yet be discovered. Theoretically, our results support a behav- ioral ecology interpretation of settlement history, human population expansion, and economic intensifi- cation in this region. They also demonstrate Bayesian analytical methods capable of making full use of the information available in archaeological datasets.

In evolutionary psychology, it is customary to measure life-history via psychometric inventories such as the Arizona Life History Battery (ALHB). The validity of this approach has been questioned: it is argued that these measures are not congruent with biological life history events, such as the number of children, age at first birth, or pubertal timing. However, empirical data to test this critique are lacking. We therefore administered the ALHB to a convenience sample of young adults in Serbia (N = 447). We also collected information on psychosocial-biodemographic life history parameters closely related to biological life history traits: pubertal timing, onset of sexual behavior, short- and long-term mating, number of children, timing of reproduction, parenthood values, and environmental harshness. We found that correlations between these two sets of measures were rare, unsystematic, and mostly low in magnitude. Stable patterns of relations emerged only between the indicators of environmental conditions from both sets of measures. Furthermore, some ALHB indicators were found to be positively related with early fertility, which is incongruent with the conceptual foundation of ALHB. Finally, network analysis and factor analysis within each set of measures revealed different structures and that the hypothesis of unidimensionality, on which the ALHB was founded, cannot be applied to psychosocial-biodemographic life history indicators. Our results support the critique of ALHB as a set of measures lacking validity to capture biodemographic life-history parameters. ALHB measures are indeed relevant for understanding life-history variation, but they cannot be used as a substitute for specific life history characteristics. Our findings are a warning to researchers to use direct measures of biological events in order to measure life-history dynamics. [ABSTRACT FROM AUTHOR]

One of the key features of personality is the existence of interindividual differences in motivation, emotions and behavior. Individual differences may be maintained in a population if personality traits are linked to states - conditions which affect the fitness-related outcomes of personality. We tested this assumption using the participants' sex as an internal state. Personality was operationalized via basic emotional systems: FEAR, ANGER, SADNESS, SEEKING, PLAYFULNESS and CARE. We measured several fitness-related outcomes like reproductive success, residual reproductive value, reproductive timing, the onset of sexual activity and short- term mating frequency. The data were collected in a community sample via an online study (N = 635; Mage = 29.4; 69.4% females). We used linear regression to predict fitness-related outcomes by basic emotions and tested interactions between sex and emotions to the prediction of these criteria measures. Predictable sex differences in basic emotions were obtained: males [ABSTRACT FROM AUTHOR]

Traditionally, models of resource extraction assume individuals act as if they form strategies based on complete information. In reality, gathering information about environmental parameters may be costly. An efficient information gathering strategy is to observe the foraging behavior of others, termed public information. However, media can exploit this strategy by appearing to supply accurate information while actually shaping information to manipulate people to behave in ways that benefit the media or their clients. Here, I use Central Place Foraging (CPF) models to investigate how newspaper propaganda shaped ore foraging strategies of late nineteenth-century Colorado silver prospectors. Data show that optimistic values of silver ore published in local newspapers led prospectors to place mines at a much greater distance than was profitable. Models assuming perfect information neglect the possibility of misinformation among investors, and may underestimate the extent and degree of human impacts on areas of resource extraction.

Awn Reduction and the Domestication of Asian Rice: A Syndrome or Crop Improvement Trait? Although wild progenitors of Asian cultivated rice have long awns, they are shorter or absent in domesticated landraces and cultivars. Thus, one may wonder when and why such transition from awned to awnless has occurred, i.e., is the reduction of awns a domestication syndrome trait or a trait that emerged during crop improvement? The proponents of an evolutionary model of rice domestication consider the loss/reduction of seed dispersal aids as a key domestication syndrome trait, apart from the fixation of seed retention. We challenge this view by showing that early cultivators had incentives for selecting long awns before and even after the fixation of the non-shattering trait. This is because long awns prevented seed predation by animals and facilitated harvest by means of the basket-beating method, which implies that their presence improved yield and labor efficiency. Our arguments also reveal that awns perhaps have persisted long after domestication and even after the introduction of sickles. Taken together, the reduction of awns may not fit into a domestication syndrome trait, but it can most plausibly be considered as a crop improvement trait. [ABSTRACT FROM AUTHOR]

Ugan, Bright and Rogers [When is technology worth the trouble? Journal of Archaeological Science 30 (10) (2003) 1315-1329] develop procurement and processing versions of an optimization model, termed the tech investment model, to formalize the conditions that favor investing time in the manufacture of more productive but more costly technologies. Their approach captures the tradeoffs that occur as less costly versions are supplanted by more costly versions of the same category of technology (e.g., fishhooks), but not the tradeoffs that occur when more costly categories of technology supplant different but less costly categories used for the same purpose (e.g., hook and line vs. spear). We (i) propose an alternative model in which different categories of technology are characterized by separate cost-benefit curves, (ii) develop point-estimate and curve-estimate versions on this model, and (iii) show how they might be applied using the development of weaponry in aboriginal California as an example. © 2005 Elsevier Ltd. All rights reserved.

Researchers across the social sciences have long been interested in families. How people make decisions such as who to marry, when to have a baby, how big or small a family to have, or whether to stay with a partner or stray are questions that continue to interest economists, sociologists, demographers, and anthropologists. Human families vary across the globe; different cultures have different marriage practices, different ideas about who raises children, and even different notions of what a family is. Human behavioral ecology is a branch of anthropology that is particularly interested in cultural variation of family systems and how these differences impact upon the people that inhabit them; the children, parents, grandparents. It draws on evolutionary theory to direct research and generate testable hypotheses to uncover how different ecologies, including social contexts, can explain diversity in families. In this Special Issue on the behavioral ecology of the family, we have collated a selection of papers that showcase just how useful this framework is for understanding cultural variation in families, which we hope will convince other social scientists interested in family research to draw upon evolutionary and ecological insight in their own work.

For girls and women, marriage under 18 years is commonplace in many low-income nations today and was culturally widespread historically. Global health campaigns refer to marriage below this threshold as ‘child marriage’ and increasingly aim for its universal eradication, citing its apparent negative wellbeing consequences. Here, we outline and evaluate four alternative hypotheses for the persistence of early marriage, despite its associations with poor wellbeing, arising from the theoretical framework of human behavioral ecology. First, early marriage may be adaptive (e.g., it maximizes reproductive success), even if detrimental to wellbeing, when life expectancy is short. Second, parent–offspring conflict may explain early marriage, with parents profiting economically at the expense of their daughter’s best interests. Third, early marriage may be explained by intergenerational conflict, whereby girls marry young to emancipate themselves from continued labor within natal households. Finally, both daughters and parents from relatively disadvantaged backgrounds favor early marriage as a ‘best of a bad job strategy’ when it represents the best option given a lack of feasible alternatives. The explanatory power of each hypothesis is context-dependent, highlighting the complex drivers of life history transitions and reinforcing the need for context-specific policies addressing the vulnerabilities of adolescence worldwide.

Abstract: Child survival is probabilistic, but the unpredictability in family formation and completed family size has been neglected in the fertility literature. In many societies, ending the family cycle with too few or too many surviving offspring entails serious social, economic, or fitness consequences. A model of risk‐ (or variance‐) sensitive adaptive behavior that addresses long‐term fertility outcomes is presented. The model shows that under conditions likely to be common, optimal, risk‐sensitive reproductive strategies deviate systematically from the completed family size that would be expected if reproductive outcome is were predictable. This is termed the “variance compensation hypothesis.” Variance compensation may be either positive or negative, resulting in augmented or diminished fertility. Which outcome obtained is a function of identifiable social, economic, and environmental factors. Through its effect on fertility behavior, variance compensation has a direct bearing on birth spacing and completed fertility, and thereby on problems in demography and human population biology ranging from demographic transitions to maternal depletion and child health. Risk‐sensitive models will be a necessary component of a general theory of fertility. Am. J. Hum. Biol. 14:168–183, 2002. © 2002 Wiley‐Liss, Inc.

Evolutionary social science applies theory and method developed in evolutionary biology, anthropology, psychology and economics to understand adaptive variation in human behavior, particularly social behavior. Hypotheses and models about resource use, mating and parenting strategies, and cooperation and competition are derived from evolutionary theory, and empirically tested to understand how humans adapt to their diverse natural and social environments.

This paper has three goals:(1) 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 theproduct of species-wide adaptive goals which must be realized in highly diverse, socio-environmental circumstances. 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.).

Child survival is probabilistic, but the unpredictability in family formation and completed family size has been neglected in the fertility literature. In many societies, ending the family cycle with too few or too many surviving offspring entails serious social, economic, or fitness consequences. A model of risk- or variance-) sensitive adaptive behavior that addresses long-term fertility outcomes is presented. The model shows that under conditions likely to be common, optimal, risk-sensitive reproductive strategies deviate systematically from the completed family size that would be expected if reproductive outcome is were predictable. This is termed the ÔÔvariance com- pensation hypothesis.ÕÕ Variance compensation may be either positive or negative, resulting in aug- mented or diminished fertility. Which outcome obtained is a function of identifiable social, economic, and environmental factors. Through its effect on fertility behavior, variance compensation has a direct bearing on birth spacing and completed fertility, and thereby on problems in demography and human population biology ranging from demographic transitions to maternal depletion and child health. Risk-sensitive models will be a necessary component of a general theory of fertility.