Juvenile foraging among the Hadza: Implications for human life history

The longstanding view that children among foraging populations are largely dependent on the food collection efforts of others is an assumed and implicit characteristic of several models of human life history and family formation. The evolution of protracted juvenility in humans is often explained using the “embodied capital model” which argues that prolonged investment in growth and delayed reproduction evolved because a long training period is required to learn difficult foraging tasks and become a self-sufficient forager. The model suggests that if juvenile investment in growth and learning yields an increase in adult productivity, then selection will favor delayed maturity, long life span, and increased brain size. Here, we test the embodied capital model with naturalistic foraging and consumption data among juvenile Hadza hunter–gatherers of Tanzania to determine the extent to which children self-provision. We found that sex had a significant effect on both the type and the amount of food brought back to camp and consumed while out foraging; compared to their male counterparts, young female foragers consumed less while foraging and returned to camp with more food. A wide variation in caloric returns was seen across all foragers in the sample. When analyzing only food brought back to camp, age was not a significant predictor. When combining the amount of food back to camp and the amount consumed while out foraging, however, older children consistently collected more food. The data presented here suggest that although older children do appear to have greater overall foraging success, even very young children are capable of collecting a considerable amount of food. Our data, although lending support to the embodied capital model, suggest that although foraging efficiency increases with age, it remains difficult to determine if this efficiency is a byproduct of learning, strength, or perhaps individual motivation. In addition, our results indicate that juvenile self-provisioning may have played a key role in the evolution of food sharing and cooperation during hominin evolution.     

Eye Tracking Young Children with Autism

The rise of accessible commercial eye-tracking systems has fueled a rapid increase in their use in psychological and psychiatric research. By providing a direct, detailed and objective measure of gaze behavior, eye-tracking has become a valuable tool for examining abnormal perceptual strategies in clinical populations and has been used to identify disorder-specific characteristics¹, promote early identification², and inform treatment³. In particular, investigators of autism spectrum disorders (ASD) have benefited from integrating eye-tracking into their research paradigms^4-7. Eye-tracking has largely been used in these studies to reveal mechanisms underlying impaired task performance⁸ and abnormal brain functioning⁹, particularly during the processing of social information^1,10-11. While older children and adults with ASD comprise the preponderance of research in this area, eye-tracking may be especially useful for studying young children with the disorder as it offers a non-invasive tool for assessing and quantifying early-emerging developmental abnormalities^2,12-13. Implementing eye-tracking with young children with ASD, however, is associated with a number of unique challenges, including issues with compliant behavior resulting from specific task demands and disorder-related psychosocial considerations. In this protocol, we detail methodological considerations for optimizing research design, data acquisition and psychometric analysis while eye-tracking young children with ASD. The provided recommendations are also designed to be more broadly applicable for eye-tracking children with other developmental disabilities. By offering guidelines for best practices in these areas based upon lessons derived from our own work, we hope to help other investigators make sound research design and analysis choices while avoiding common pitfalls that can compromise data acquisition while eye-tracking young children with ASD or other developmental difficulties.     

Racial characteristics from the industrial anthropology aspect

Often industrial-anthropological research cannot be limited to a particular population. Whenever export and/or migration brings people and conditions together which go beyond the usual area of a population characterized by a particular morphological trait, the question arises as to how technical conditions can best be adapted to humans. The automobile seat is used to illustrate to what extent race-specific size and body proportion differences effect technical practice. Since the safety of an automobile is in part dependent upon an efficient adaptation of the vehicle to the user, these investigations have considerable practical importance.     

Early false-belief understanding in traditional non-Western societies

The psychological capacity to recognize that others may hold and act on false beliefs has been proposed to reflect an evolved, species-typical adaptation for social reasoning in humans; however, controversy surrounds the developmental timing and universality of this trait. Cross-cultural studies using elicited-response tasks indicate that the age at which children begin to understand false beliefs ranges from 4 to 7 years across societies, whereas studies using spontaneous-response tasks with Western children indicate that false-belief understanding emerges much earlier, consistent with the hypothesis that false-belief understanding is a psychological adaptation that is universally present in early childhood. To evaluate this hypothesis, we used three spontaneous-response tasks that have revealed early false-belief understanding in the West to test young children in three traditional, non-Western societies: Salar (China), Shuar/Colono (Ecuador) and Yasawan (Fiji). Results were comparable with those from the West, supporting the hypothesis that false-belief understanding reflects an adaptation that is universally present early in development.     

Immune remodeling: lessons from repertoire alterations during chronological aging and in immune-mediated disease

Immunological studies of aging and of patients with chronic immune-mediated diseases document overlap of immune phenotypes. Here, the term "immune remodeling" refers to these phenotypes that are indicative of biological processes of deterioration and repair. This concept is explored through lessons from studies about the changes in the T-cell repertoire and the functional diversity of otherwise oligoclonal, senescent T cells. Immune remodeling suggests a gradual process that occurs throughout life. However, similar but more drastic remodeling occurs disproportionately among young patients with chronic disease. In this article, I propose that immune remodeling is a beneficial adaptation of aging to promote healthy survival beyond reproductive performance, but acute remodeling poses risk of premature exhaustion of the immune repertoire and, thus, is detrimental in young individuals.     

Giving Voice to Children's Voices: Practices and Problems, Pitfalls and Potentials

In this article, I explore the lessons that the anthropological debates of the 1980s about writing culture might have for contemporary childhood research within anthropology and the social sciences more generally. I argue that the current rhetoric about "giving voice to children," commonplace both inside and outside the academy, poses a threat to the future of childhood research because it masks a number of important conceptual and epistemological problems. In particular, these relate to questions of representation, issues of authenticity, the diversity of children's experiences, and children's participation in research, all of which need to be addressed by anthropologists in their own research practices with children. Unless anthropologists do so, childhood research risks becoming marginalized once more and will fail to provide an arena within which children are seen as social actors who can provide a unique perspective on the social world about matters that concern them as children.     

EVOLUTIONARY EPIDEMIOLOGY AND THE DYNAMICS OF ADAPTATION

The mean fitness of a population, often equal to its growth rate, measures its level of adaptation to particular environmental conditions. A better understanding of the evolution of mean fitness could thus provide a natural link between evolution and demography. Yet, after the seminal work of Fisher and its renowned "fundamental theorem of natural selection," the dynamics of mean fitness has attracted little attention, and mostly from theoretical population geneticists. Here we analyze the dynamics of mean fitness in the context of host-parasite interactions. We illustrate the potential relevance of this analysis under different scenarios ranging from a simple situation in which a parasite evolves in a homogeneous host population to a more complex one with host-parasite coevolution. In each case, we contrast the effects of natural selection, recurrent mutations, and the change of the biotic environment, on the dynamics of adaptation. Decoupling these three components helps elucidate the interplay between evolutionary and ecological dynamics. In particular, it offers new perspectives on situations leading to evolutionary suicide. As mean fitness is an easily measurable quantity in microbial systems, this analysis provides new ways to track the dynamics of adaptation in experimental evolution and coevolution studies.     

Street smarts and urban myths: women, sex work, and the role of storytelling in risk reduction and rationalization

Storytelling has a strong tradition in inner-city American communities. In this article, we examine patterns of storytelling among a sample of drug-using women from New York City who engage in street-based sex work. We consider two particular formats of storytelling for analysis: "street smarts" and "urban myths." Street smarts are stories of survival, and urban myths are compilations of street legends spread by word of mouth. The narratives are filled with tales of extreme risk across situations. The women used the stories to delineate the boundaries of risk as well as to rationalize risks they deemed to be inevitable but temporary in their lives. Few of the women capitalized on the greater instructive quality of the stories toward increased risk reduction, which may relate to the women's distance from an identity of "sex worker." If properly harnessed, the strength of storytelling suggests new avenues for risk-reduction interventions.     

Social psychological and sexological aspects of oral contraception (author's transl)]

An inventory is made on the hindrances to the acceptance of contraception in general and oral contraception in particular. They are grouped as hindrances related to the social and psychological significance of "making children", hindrances related to the social and psychological significance of "having children" hindrances, related to the method of oral contraception itself, to be divided in social hindrances, psychological hindrances and medical hindrances and finally hindrances related to the provision of the pill to the individual user. Each of these is amply discussed, the author expresses the hope that by identification of these hindrances, lessons may be learned for the future, when other methods of contreception become available.     

A multinomial model for estimating the size of a whale population from incomplete census data

This paper adapts the removal method of population size estimation to the problem of estimating the size of the western Arctic stock of bowhead whales. The whales are counted during their spring migration as they pass two census camps located near Point Barrow, Alaska. Whales seen at the first camp are "removed" from the population of concern to the second camp, where only whales missed by the first camp are counted. If both camps were in operation throughout the migration and if the probability of missing a whale were constant, the removal method would provide a population size estimate based on a trinomial model in which the size of the population would be the number of trials, whales counted by each camp would provide the observed cell totals, and whales missed by both camps would represent an unobserved cell total. Since the probability of missing a whale depends on visibility, we model the population size as the sum of the number of trials of several independent trinomial distributions, each of which represents a particular visibility condition occurring during the census. To account for the fact that watch cannot be maintained at both camps throughout the migration, we derive a confidence interval estimate of the number of trials under a more general model allowing for incomplete observation of totals within particular cells as well as for completely unobserved cells.     

A bright spot analysis of inland recreational fisheries in the face of climate change: learning about adaptation from small successes

Inland recreational fisheries have social, economic, and ecological importance worldwide but these fisheries are increasingly challenged by the diverse effects of climate change. Coupled with other anthropogenic stressors, climate change has contributed to declines in freshwater biodiversity of greater severity than those observed across marine or terrestrial taxa. At a macro level, inland fisheries are experiencing declines. There are, however, a number of success stories, or ‘bright spots,’ in inland recreational fisheries management, where innovative approaches are leading to increases in social and ecological well-being in the face of climate change. Cases such as these are important sources of inspiration and learning about adaptation to climate and environmental change. In this article, we analyze 11 examples of such ‘bright spots’ drawn from multiple jurisdictions around the world from which we extracted lessons that might apply to fisheries management challenges beyond the region and context of each case. Collectively, these bright spots highlight adaptive initiatives that allow for recreational fisheries management to mitigate to stressors associated with current and future climate change. Examples identified include community-based restoration projects, collaborative and adaptive approaches to short-term fisheries closures, transdisciplinary large-scale conservation projects, and conservation-minded efforts by individuals and communities. By highlighting examples of ‘small wins’ within inland recreational fisheries management, this review contributes to the idea that a ‘positive future’ for inland recreational fisheries in the face of climate change is possible and highlights potential strategies to adapt to current and future climate scenarios.

     

The evolution of the dicynodont feeding system

The skull structure of dicynodonts may be regarded as a complex adaptation towards herbivorous feeding. The present work examines how and why this adaptation may have evolved. A cladogram of the dicynodonts is presented and from it a sequence of hypothetical ancestral forms is inferred. The jaw musculature of dicynodonts and other therapsids is described and in particular the early dicynodont Eodicynodon oosthuizeni is described in detail. This information is used to draw up a sequence of ancestral stages whose basic skull anatomy, jaw muscle organization and masticatory properties are described. Differences in masticatory properties between these stages are pinpointed and an explanation to account for the development of these differences is advanced. It is concluded that the changes in skull organization seen during the evolution of dicynodonts are consistent with the hypothesis that a propalinal jaw action was being improved by selection, and that this was required to permit dicynodonts to be efficient herbivores.     

Age Differences in the Neuroelectric Adaptation to Meaningful Sounds

Much of what we know regarding the effect of stimulus repetition on neuroelectric adaptation comes from studies using artificially produced pure tones or harmonic complex sounds. Little is known about the neural processes associated with the representation of everyday sounds and how these may be affected by aging. In this study, we used real life, meaningful sounds presented at various azimuth positions and found that auditory evoked responses peaking at about 100 and 180 ms after sound onset decreased in amplitude with stimulus repetition. This neural adaptation was greater in young than in older adults and was more pronounced when the same sound was repeated at the same location. Moreover, the P2 waves showed differential patterns of domain-specific adaptation when location and identity was repeated among young adults. Background noise decreased ERP amplitudes and modulated the magnitude of repetition effects on both the N1 and P2 amplitude, and the effects were comparable in young and older adults. These findings reveal an age-related difference in the neural processes associated with adaptation to meaningful sounds, which may relate to older adults’ difficulty in ignoring task-irrelevant stimuli.     

Applying Quantitative Genetic Methods to Primate Social Behavior

Increasingly, behavioral ecologists have applied quantitative genetic methods to investigate the evolution of behaviors in wild animal populations. The promise of quantitative genetics in unmanaged populations opens the door for simultaneous analysis of inheritance, phenotypic plasticity, and patterns of selection on behavioral phenotypes all within the same study. In this article, we describe how quantitative genetic techniques provide studies of the evolution of behavior with information that is unique and valuable. We outline technical obstacles for applying quantitative genetic techniques that are of particular relevance to studies of behavior in primates, especially those living in noncaptive populations, e.g., the need for pedigree information, non-Gaussian phenotypes, and demonstrate how many of these barriers are now surmountable. We illustrate this by applying recent quantitative genetic methods to spatial proximity data, a simple and widely collected primate social behavior, from adult rhesus macaques on Cayo Santiago. Our analysis shows that proximity measures are consistent across repeated measurements on individuals (repeatable) and that kin have similar mean measurements (heritable). Quantitative genetics may hold lessons of considerable importance for studies of primate behavior, even those without a specific genetic focus.     

Teaching Evolution Concepts to Early Elementary School Students

State and national standards call for teaching evolution concepts as early as kindergarten, which provides motivation to continue developing science instruction and curriculum for young learners. The importance of addressing students’ folk theories regarding science justifies teaching evolution early in K-12 education. In this project, we developed, implemented, and researched standards-based lessons to teach elements of evolution (speciation and adaption) to kindergarteners and second graders. Our lessons attended to the students’ prior knowledge, and utilized inquiry and modeling to teach and assess their ability to recognize patterns of similarity and differences among organisms. Using their products and comments as evidence, it was apparent the students were able to communicate recognition of patterns and effectively apply their knowledge in near transfer activities, indicating they achieved our learning objectives. This provides support for teaching evolution concepts in the early grades and evidence of the ability for young children to effectively engage in supported inquiry and modeling for learning science.     

Between Myth and Madness: The Premigration Dream of Leaving Among Young Somali Refugees

Many young Somali refugees experience long premigration waits and a poorly delimited transition period in a succession of countries before reaching their final destination. During this difficult passage, a myth dealing with departure and exodus is collectively constructed, and it serves as a dynamic, mobilizing dream that orients individual strategies. This substitution of 'dream travel' for real travel during the transition period, especially if it is prolonged, may cause Somali youths to lose contact with reality and eventually to slide into madness. The authors' approach is based on three assumptions: (a) that pastoralism predisposes the Somali to value travel as a way of maturing, (b) that age-based peer groups create special migratory dynamics, and (c) that an ethic of solidarity involves many people in the adventure of a migrant youth. When trapped in an indefinite transition period, young men share khat-chewing sessions during which they relate success stories and dreams of leaving. Many grow frustrated with the delay, and if their departure plans fall through, the 'dream trip' often becomes 'dream madness.' Actual cases illustrate how some young Somali get lost in their dreams. A young Somali's vulnerability is heightened when he extricates himself from the system of reciprocal obligations or when the liminal stage ends with the mourning of the impossible dream. In the universe of madness visited by some young Somali migrants, the boundaries between the real and the imaginary are poorly marked. The paper is based on fieldwork carried out in the Horn of Africa and in Canada, interviews with Somali immigrants and members of the community, and clinical psychiatric data collected in Montreal.     

Narrative mediation of conventional and new "mental health" paradigms: reading the stories of immigrant Iranian women

The potential of storytelling to effect change and produce new knowledge is being recognized across disciplines. Two conditions are necessary to realize these goals: first, reading of stories must be contextualized to include larger social and political landscapes; and second, how stories are read and toward what end must be closely examined. This article explores these issues with reference to the subject of the "mental health" or emotional well-being of a cohort of postrevolution Iranian women from metropolitan Vancouver, British Columbia. Reading their stories at a particular moment in time shows that well-being is essentially grounded in spaces and places where we live, work, and engage in social interactions. This commonplace knowledge, which is subdued in medical discourse, is retrieved through Iranian women's stories of life and living told at a time when their experiences, histories, and viewpoints on health are subject to erasure.     

A brief overview of mouse models of pulmonary arterial hypertension: problems and prospects

Many chronic pulmonary diseases are associated with pulmonary hypertension (PH) and pulmonary vascular remodeling, which is a term that continues to be used to describe a wide spectrum of vascular abnormalities. Pulmonary vascular structural changes frequently increase pulmonary vascular resistance, causing PH and right heart failure. Although rat models had been standard models of PH research, in more recent years the availability of genetically engineered mice has made this species attractive for many investigators. Here we review a large amount of data derived from experimental PH reports published since 1996. These studies using wild-type and genetically designed mice illustrate the challenges and opportunities provided by these models. Hemodynamic measurements are difficult to obtain in mice, and right heart failure has not been investigated in mice. Anatomical, cellular, and genetic differences distinguish mice and rats, and pharmacogenomics may explain the degree of PH and the particular mode of pulmonary vascular adaptation and also the response of the right ventricle.     

A critical analysis of parameter adaptation in ant colony optimization

Applying parameter adaptation means operating on parameters of an algorithm while it is tackling an instance. For ant colony optimization, several parameter adaptation methods have been proposed. In the literature, these methods have been shown to improve the quality of the results achieved in some particular contexts. In particular, they proved to be successful when applied to novel ant colony optimization algorithms for tackling problems that are not a classical testbed for optimization algorithms. In this paper, we show that the adaptation methods proposed so far do not improve, and often even worsen the performance when applied to high performing ant colony optimization algorithms for some classical combinatorial optimization problems.