Ethnobotanical knowledge is associated with indices of child health in the Bolivian Amazon

Pearl Memorial Lecture. Humans at the extremes: Exploring human adaptation to ecological and social stressors

The field of human biology has long explored how human populations have adapted to extreme environmental circumstances. Yet, it has become increasingly clear that conditions of social stress, poverty, and lifestyle change play equally important roles in shaping human biological variation and health. In this paper, I provide a brief background on the foundational human adaptability research of the International Biological Programme (IBP) from the 1960s, highlighting how its successes and critiques have shaped current research directions in the field. I then discuss and reflect on my own field research that has examined the influence of both environmental and social stresses on human populations living in different ecosystems: the Peruvian Andes, the Siberian arctic, and the Bolivian rainforest. Finally, I consider how the papers in this special issue advance our understanding of human adaptability to extreme conditions and offer directions for future research. Drawing on our field's distinctive evolutionary and biocultural perspectives, human biologists are uniquely positioned to examine how the interplay between social and ecological domains influences the human condition.

Medicinal plants meet modern biodiversity science

Plants have been an essential source of human medicine for millennia. In this review, we argue that a holistic, interdisciplinary approach to the study of medicinal plants that combines methods and insights from three key disciplines - evolutionary ecology, molecular biology/biochemistry, and ethnopharmacology - is poised to facilitate new breakthroughs in science, including pharmacological discoveries and rapid advancements in human health and well-being. Such interdisciplinary research leverages data and methods spanning space, time, and species associated with medicinal plant species evolution, ecology, genomics, and metabolomic trait diversity, all of which build heavily on traditional Indigenous knowledge. Such an interdisciplinary approach contrasts sharply with most well-funded and successful medicinal plant research during the last half-century, which, despite notable advancements, has greatly oversimplified the dynamic relationships between plants and humans, kept hidden the larger human narratives about these relationships, and overlooked potentially important research and discoveries into life-saving medicines. We suggest that medicinal plants and people should be viewed as partners whose relationship involves a complicated and poorly explored set of (socio-)ecological interactions including not only domestication but also commensalisms and mutualisms. In short, medicinal plant species are not just chemical factories for extraction and exploitation. Rather, they may be symbiotic partners that have shaped modern societies, improved human health, and extended human lifespans.

Ethnobotanical study on medicinal plants used by Bulang people in Yunnan, China

BACKGROUND

Despite the popularity of modern medicine, medicinal plants remain a cornerstone of treatment for numerous diseases, particularly among ethnic groups and tribal communities around the globe. Ethnomedicine offers advantages such as ease of use, convenience, and economic benefits. Medicinal plant knowledge within Bulang ethnic community of southwest China is a valuable complement to Chinese ethnomedicine systems. Accumulated medical knowledge is due to the extensive length of occupation by Bulang People, considered the earliest inhabitants of Xishuangbanna; this has resulted in the development of various traditional treatment methods with local characteristics and unique curative effects. Therefore, there is exceeding value in exploring the medical knowledge of Bulang.

METHODS

A total of 175 local informants participated in the interviews and distribution of questionnaires in 10 Bulang villages in Menghai County, Xishuangbanna Prefecture, Yunnan Province, China. We documented the community of Bulang's use of medicinal herbs, and we used both the informant consensus factor (ICF) and use value (UV) methodologies to analyze the data. Furthermore, we conducted a comparative study to explore the potential of Bulang traditional medicine by comparing it to traditional Dai medicine.

RESULTS

The study recorded 60 medicinal plant species belonging to 41 families and 59 genera, including 22 species of herb, 22 species of shrub, nine species of trees, and seven species of liana. Araceae, Compositae, Lamiaceae and Leguminosae were found to have the highest number of species. The affordability and cultural heritage of Bulang medicine make it advantageous, Investigated Informants report that increased usage of Western medicine (88%), less availability of herbal medicine (95.43%), and the reduction in medicinal plant resources (80.57%) pose significant threats to Bulang medicine. All Bulang medicinal plants are naturally grown, with only 22 per cent being cultivated. Camellia sinensis (0.94) and Zingiber officinale (0.89) showed the highest UV values, while the function of Phyllanthus emblica L. and Houttuynia cordata Thunb. were also noted. The ICF revealed digestive system related diseases were the most commonly treated, with conditions of the motor system using the highest number of plant species. Finally, a comparison with traditional Dai medicine determined that 22 plants (36.67%) of the 60 surveyed had higher medicinal value in Bulang medicine.

CONCLUSION

Bulang communities primarily source medicinal plants from the wild. Should environmental damage lead to the extinction of these medicinal plants, it could result in a shift toward modern Western medicine as a preferred medical treatment. Bulang ethnomedicine is a vital supplement to China's traditional medicine, particularly aspects of ethnic medicine relevant to daily life. Future research should emphasize inter-ethnic medical studies to reveal the untapped potential of medicinal plants.

Cultural evolution from the producers' standpoint

Standard approaches to cultural evolution focus on the recipients or consumers. This does not take into account the fitness costs incurred in producing the behaviours or artefacts that become cultural, i.e. widespread in a social group. We argue that cultural evolution models should focus on these fitness costs and benefits of cultural production, particularly in the domain of 'symbolic' culture. In this approach, cultural products can be considered as a part of the extended phenotype of producers, which can affect the fitness of recipients in a positive way (through cooperation) but also in a detrimental way (through manipulation and exploitation). Taking the producers' perspective may help explain the specific features of many kinds of cultural products.

Gendered traditional agroecological knowledge in agri-food systems: a systematic review

Traditional agroecological knowledge (i.e. TAeK) is gaining recognition for its potential contribution to climate change adaptation in food systems, ecosystems restoration and food insecurity. Despite the existing literature on Traditional Ecological Knowledge and its nexus with food security, how gender critically influences the distribution of such knowledge within agri-food systems has not yet been systematically analysed. In this regard, this systematic review attempts to answer four questions: 1) How does the literature on gender and TAeK in agri-food systems evolved temporally, geographically and in different agroecosystems? 2) How are gender and intersectionality mainly approached by such literature? 3) How do the articles address gendered dimensions in TAeK within the agri-food system activities? 4) What are the main drivers of change that influence TAeK and adaptive responses? The results show the gendered nature of TAeK in relation to food production, processing, and conservation activities, and how these activities are linked to tasks and activities, gender-specific knowledge, and spaces where gender discrimination is reproduced. The review also identifies elements that delimit and/or take part of the development of TAeK, such as gendered access to resources, gendered institutions, and the identification of the main drivers of change and impacts of TAeK erosion and biodiversity loss. These results are discussed in terms of power relations that interact with sociocultural norms and practices according to the specific geographical context and agroecosystem.

Homo medicus: The transition to meat eating increased pathogen pressure and the use of pharmacological plants in Homo

The human lineage transitioned to a more carnivorous niche 2.6 mya and evolved a large body size and slower life history, which likely increased zoonotic pathogen pressure. Evidence for this increase includes increased zoonotic infections in modern hunter-gatherers and bushmeat hunters, exceptionally low stomach pH compared to other primates, and divergence in immune-related genes. These all point to change, and probably intensification, in the infectious disease environment of Homo compared to earlier hominins and other apes. At the same time, the brain, an organ in which immune responses are constrained, began to triple in size. We propose that the combination of increased zoonotic pathogen pressure and the challenges of defending a large brain and body from pathogens in a long-lived mammal, selected for intensification of the plant-based self-medication strategies already in place in apes and other primates. In support, there is evidence of medicinal plant use by hominins in the middle Paleolithic, and all cultures today have sophisticated, plant-based medical systems, add spices to food, and regularly consume psychoactive plant substances that are harmful to helminths and other pathogens. We propose that the computational challenges of discovering effective plant-based treatments, the consequent ability to consume more energy-rich animal foods, and the reduced reliance on energetically-costly immune responses helped select for increased cognitive abilities and unique exchange relationships in Homo. In the story of human evolution, which has long emphasized hunting skills, medical skills had an equal role to play.

Diversity, distribution, and sustainability of traditional medicinal plants in Kaski district, western Nepal

Medicinal plants are the primary source of traditional healthcare systems in many rural areas mostly in developing countries. This study aimed to document and analyze the diversity, distribution, and sustainability of the traditional medicinal plants used by the Gurung people of the Sikles region in western Nepal. Ethnobotanical data were collected through focus group discussions and individual interviews, and analyzed using descriptive and inferential statistics. Prior informed consent was obtained before each interview. Quantitative ethnobotanical indices such as informant consensus factor, relative frequency of citation, and use values were also calculated. A possible association among these indices was tested using correlation analysis. A total of 115 wild medicinal plant species belonging to 106 genera and 71 families were documented. Asteraceae and Rosaceae were the dominant families whereas herbs were the most dominant life form. Roots were the most used plant part, paste was the most common method of preparation, and most of the medical formulations were taken orally. The highest number of medicinal plants were used to treat stomach disorders. The average informant consensus value of 0.79 indicates a high consensus among respondents in selecting medicinal plants. Lindera neesiana, Neopicrorhiza scrophulariiflora, Paris polyphylla, and Bergenia ciliata were found to be high-ranking medicinal plants based on the relative frequency of citation and use value. The genders did not affect medicinal plants' knowledge but age had a significant correlation. Most of the informants agreed that medicinal plants are under pressure due to overharvesting and a lack of proper forest management practices. The number of medicinal plants reported from the study area indicates that the Gurung people possess rich traditional knowledge, and the vegetation of the Sikles region constitutes rich diversity of medicinal plants.

All Models Are Wrong, and Some Are Religious: Supernatural Explanations as Abstract and Useful Falsehoods about Complex Realities

Many cognitive and evolutionary theories of religion argue that supernatural explanations are byproducts of our cognitive adaptations. An influential argument states that our supernatural explanations result from a tendency to generate anthropomorphic explanations, and that this tendency is a byproduct of an error management strategy because agents tend to be associated with especially high fitness costs. We propose instead that anthropomorphic and other supernatural explanations result as features of a broader toolkit of well-designed cognitive adaptations, which are designed for explaining the abstract and causal structure of complex, unobservable, and uncertain phenomena that have substantial impacts on fitness. Specifically, we argue that (1) mental representations about the abstract vs. the supernatural are largely overlapping, if not identical, and (2) when the data-generating processes for scarce and ambiguous observations are complex and opaque, a naive observer can improve a bias-variance trade-off by starting with a simple, underspecified explanation that Western observers readily interpret as "supernatural." We then argue that (3) in many cases, knowledge specialists across cultures offer pragmatic services that involve apparently supernatural explanations, and their clients are frequently willing to pay them in a market for useful and effective services. We propose that at least some ethnographic descriptions of religion might actually reflect ordinary and adaptive responses to novel problems such as illnesses and natural disasters, where knowledge specialists possess and apply the best available explanations about phenomena that would otherwise be completely mysterious and unpredictable.

Rates of ecological knowledge learning in Pemba, Tanzania: Implications for childhood evolution

Humans live in diverse, complex niches where survival and reproduction are conditional on the acquisition of knowledge. Humans also have long childhoods, spending more than a decade before they become net producers. Whether the time needed to learn has been a selective force in the evolution of long human childhood is unclear, because there is little comparative data on the growth of ecological knowledge throughout childhood. We measured ecological knowledge at different ages in Pemba, Zanzibar (Tanzania), interviewing 93 children and teenagers between 4 and 26 years. We developed Bayesian latent-trait models to estimate individual knowledge and its association with age, activities, household family structure and education. In the studied population, children learn during the whole pre-reproductive period, but at varying rates, with the fastest increases in young children. Sex differences appear during middle childhood and are mediated by participation in different activities. In addition to providing a detailed empirical investigation of the relationship between knowledge acquisition and childhood, this study develops and documents computational improvements to the modelling of knowledge development.

Kaniuwatewara (when we get sick): understanding health-seeking behaviours among the Shawi of the Peruvian Amazon

Background

Detailed qualitative information regarding Indigenous populations’ health-seeking behaviours within Peru’s plural healthcare system is lacking. Such context-specific information is prerequisite to developing evidence-based health policies and programs intended to improve health outcomes for Indigenous populations. To this end, this study aimed to characterize health-seeking behaviours, factors affecting health-seeking behaviours, and barriers to obtaining healthcare in two Indigenous Shawi communities in Peru.

Methods

Community-based approaches guided this work, and included 40 semi-structured interviews and a series of informal interviews. Data were analysed thematically, using a constant comparative method; result authenticity and validity were ensured via team debriefing, member checking, and community validation.

Results

Shawi health-seeking behaviours were plural, dynamic, and informed by several factors, including illness type, perceived aetiology, perceived severity, and treatment characteristics. Traditional remedies were preferred over professional biomedical healthcare; however, the two systems were viewed as complementary, and professional biomedical healthcare was sought for illnesses for which no traditional remedies existed. Barriers impeding healthcare use included distance to healthcare facilities, costs, language barriers, and cultural insensitivity amongst professional biomedical practitioners. Nevertheless, these barriers were considered within a complex decision-making process, and could be overridden by certain factors including perceived quality or effectiveness of care.

Conclusions

These findings emphasize the importance of acknowledging and considering Indigenous culture and beliefs, as well as the existing traditional medical system, within the professional healthcare system. Cultural competency training and formally integrating traditional healthcare into the official healthcare system are promising strategies to increase healthcare service use, and therefore health outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11574-2.

Language extinction triggers the loss of unique medicinal knowledge

Over 30% of the 7,400 languages in the world will no longer be spoken by the end of the century. So far, however, our understanding of whether language extinction may result in the loss of linguistically unique knowledge remains limited. Here, we ask to what degree indigenous knowledge of medicinal plants is associated with individual languages and quantify how much indigenous knowledge may vanish as languages and plants go extinct. Focusing on three regions that have a high biocultural diversity, we show that over 75% of all 12,495 medicinal plant services are linguistically unique-i.e., only known to one language. Whereas most plant species associated with linguistically unique knowledge are not threatened, most languages that report linguistically unique knowledge are. Our finding of high uniqueness in indigenous knowledge and strong coupling with threatened languages suggests that language loss will be even more critical to the extinction of medicinal knowledge than biodiversity loss.

Nuya kankantawa (we are feeling healthy): Understandings of health and wellbeing among Shawi of the Peruvian Amazon

Promoting and supporting Indigenous health includes ensuring health services reflect local concepts of health. There is, therefore, a need to better understand context-specific Indigenous understandings of health in order to design culturally appropriate health services. To this end, this study characterized two Shawi communities' understandings of what it means to be healthy. Using a community-based participatory research approach, 40 semi-structured interviews and a series of informal interviews were conducted and analysed thematically, using a constant comparative method. The Shawi definition of health extended beyond individual physical welfare and focused on emotional, collective, and environmental wellbeing. The primary factors underlying Shawi perceptions of health and wellbeing included providing for the family, ensuring the welfare of others, maintaining positive social relationships, preserving traditional values and practices, and living harmoniously with the natural environment. Conversely, Shawi classified illnesses according to their cause or treatment. These included illnesses caused by sorcery, those caused by spirits of the forest, and 'new diseases,' that first appeared in the communities when they were contacted by the Western civilization, for which no traditional remedies existed. Consequently, according to Shawi, sociocultural, environmental, and climatic changes are posing imminent health threats. This study highlights the differences between biomedical and Indigenous Shawi health understandings, and therefore emphasizes the importance of acknowledging and embracing Shawi culture and beliefs within the formal healthcare system.

Sex-specific differences in somatic investment and strategies of physical activity among Portuguese schoolchildren

OBJECTIVES

Physical activity (PA) is required for healthy growth, development, and maturation and plays an important role in the prevention of overweight and obesity in childhood and adolescence. Sex-differences in PA levels are well documented, with boys spending more time in PA, especially in moderate-to-vigorous activities. Following the Life History Theory, our aim is to study if PA affects the fat tissues increases during childhood and juvenile phases in both sexes.

METHODS

Time spent in sedentary, light, and moderate-to-vigorous PA levels were measured in a sample of 415 Portuguese children and juveniles (207 females/208 males; aged 6-11 years), using an accelerometer for 7 days. Skinfolds related with body fat were objectively collected and socioeconomic status factors were reported using a parental questionnaire.

RESULTS

The outcomes show that girls' and boys' fat variables increased during the end of the childhood and the juvenile phase. However, these variables were differently affected by PA. Girls increased fat variables with the sedentary activity while boys decreased fat variables with moderate-to-vigorous PA. Alike, active boys but not girls reduced the fat increase tendency with age.

CONCLUSIONS

Although both sexes displayed a general fat increment with age, moderate-to-vigorous PA dampens the increase only in boys. In fact, active girls increased body fat in the same manner as non-active girls. From an evolutionary perspective, it could explain sex-specific somatic strategies related to future reproduction or, with future mating and intrasexual competition.

The role of schools as an opportunity for transmission of local knowledge about useful Restinga plants: experiences in southeastern Brazil

BACKGROUND

The study of cultural transmission can help identify processes that influence knowledge systems dynamics and evolution, especially during childhood and youth, which are fundamental phases in acquiring survival skills. In this sense, we use the knowledge about useful restinga plants (Brazilian coastal vegetation) as an analytical model to describe, compare, and analyze cultural transmission during youth, while factoring in origin, in the Cabo Frio region, southeastern Brazil. We tested (1) whether transmission of knowledge is conservative, (2) whether immigration events define the transmission modes, (3) whether teaching is the most important social transmission cognitive process, and (4) which type of stimulus/context is most important for the knowledge transmission process.

METHODS

Questionnaires and free listings were applied to 150 high school students aged between 15 and 20 to obtain information about socioeconomic characteristics, useful plant knowledge, and cultural transmission. We analyzed the distribution of knowledge according to the informant's origin and evaluated the models, processes, and context with which this information was transmitted. The chi-square test was used to determine the association between origin, plant knowledge, and transmission as well as to reveal the most important models, modes, and processes during youth.

RESULTS

Informants provided 299 plant citations ([Formula: see text] = 1.75; s = 1.73) related to 37 species. The categories of the most cited uses were edible (93) and medicinal (32). Statistical results showed that origin did not influence knowledge distribution and transmission. In addition, although the most relevant mode was the conservative (vertical) one, the one-to-many diffuse mode (teacher) was highlighted. The new environmental context for immigrants did not influence transmission, the main transmission process was teaching, and the learning contexts were predominantly school-related.

CONCLUSION

Plant knowledge in youth was related to local edible and medicinal plants, indicating adaptive knowledge linked to material demands for survival. While the initial models for cultural transmission are family (vertical), during the development phase of juveniles, other actors become models (one-to-many). In addition, the nature of the information (survival demand) and age are more relevant to cultural transmission than the socio-environmental context.

The effect of gender targeting of food transfers on child nutritional status: Experimental evidence from the Bolivian Amazon

Some research suggests women are more likely to allocate additional resources to their children than are men. This perception has influenced policies such as in-kind food transfer programs and cash transfer programs, which often target women recipients. We assess whether targeting in-kind rice transfers to female versus male adult household members has a differential impact on children's short-run nutritional status. We estimate the impacts of transfers of edible rice and rice seeds, randomly allocated to female or male adults, on three anthropometric indicators: BMI-for-age, arm-muscle area, and triceps skinfold thickness. The trial includes 481 children aged 3-11 years in a horticultural-foraging society of native Amazonians in Bolivia. On average, the gender of the transfer recipient does not influence child anthropometric dimensions, possibly due to norms of cooperation and sharing within and between households. We find limited evidence of heterogeneity in impacts. Transfers to women help children who were growth stunted at baseline to partially catch-up to their better-nourished age-sex peers and help boys (but not girls) and children in higher-income households increase their BMI-for-age. The results of this research point to the importance of considering cultural context in determining if allocating food transfers according to gender are most effective.

Prestige and homophily predict network structure for social learning of medicinal plant knowledge

Human subsistence societies have thrived in environmental extremes while maintaining biodiversity through social learning of ecological knowledge, such as techniques to prepare food and medicine from local resources. However, there is limited understanding of which processes shape social learning patterns and configuration in ecological knowledge networks, or how these processes apply to resource management and biological conservation. In this study, we test the hypothesis that the prestige (rarity or exclusivity) of knowledge shapes social learning networks. In addition, we test whether people tend to select who to learn from based on prestige (knowledge or reputation), and homophily (e.g., people of the same age or gender). We used interviews to assess five types of medicinal plant knowledge and how 303 people share this knowledge across four villages in Solomon Islands. We developed exponential random graph models (ERGMs) to test whether hypothesized patterns of knowledge sharing based on prestige and homophily are more common in the observed network than in randomly simulated networks of the same size. We found that prestige predicts five hypothesized network configurations and all three hypothesized learning patterns, while homophily predicts one of three hypothesized network configurations and five of the seven hypothesized learning patterns. These results compare the strength of different prestige and homophily effects on social learning and show how cultural practices such as intermarriage can affect certain aspects of prestige and homophily. By advancing our understanding of how prestige and homophily affect ecological knowledge networks, we identify which social learning patterns have the largest effects on biocultural conservation of ecological knowledge.

Global WEIRDing: transitions in wild plant knowledge and treatment preferences in Congo hunter-gatherers

Cultures around the world are converging as populations become more connected. On the one hand this increased connectedness can promote the recombination of existing cultural practices to generate new ones, but on the other it may lead to the replacement of traditional practices and global WEIRDing. Here we examine the process and causes of changes in cultural traits concerning wild plant knowledge in Mbendjele BaYaka hunter-gatherers from Congo. Our results show that the BaYaka who were born in town reported knowing and using fewer plants than the BaYaka who were born in forest camps. Plant uses lost in the town-born BaYaka related to medicine. Unlike the forest-born participants, the town-born BaYaka preferred Western medicine over traditional practices, suggesting that the observed decline of plant knowledge and use is the result of replacement of cultural practices with the new products of cumulative culture.

Traditional and Local Knowledge in Chile: Review of Experiences and Insights for Management and Sustainability

Scientific interest in traditional and local knowledge (TLK) has grown in recent decades, because of the potential of TLK for improving management and conservation practices. Here, we synthesize and evaluate TLK studies in Chile, discuss how this progress compares to the international scientific literature in the field, and contextualize our results according to the multiple evidence base approach. We found 77 publications on the subject, a steady increase since 1980, and a peak production in the 1990s and the 2010s decades. Publications most often provide basic information on species names and lists of resource uses in terrestrial rather than marine ecosystems. Papers had an emphasis on natural, rather than social sciences. Work was concentrated on the extreme northern and southern regions of Chile where more indigenous populations are found. Indigenous ethnic groups received greater attention than non-indigenous people. Future work in Chile must broaden its attention to local and urban communities and focus on how TLK can contribute to management and sustainability, rather than only acquiring the basic knowledge contained in local and traditional communities. To better comprehend TLK’s contribution to policy measures, an interdisciplinary approach must be present to address these knowledge gaps.

Storing and sharing: A review of indigenous and local knowledge conservation initiatives

Despite its relative adaptive capacity and its many values, indigenous and local knowledge (ILK) is rapidly eroding. Over the past decades a myriad of efforts have emerged to prevent this erosion. In this work, we reviewed and systematically coded 138 ILK conservation initiatives published in academic papers in order to explore trends in participation, digitalization, timing, location, and approach of the initiatives. We also explored factors influencing initiative inclusiveness. Our findings reveal that ILK holders are generally absent from most phases of the studied initiatives, although IT-based and in situ initiatives (i.e., education and community based conservation) appear as the exceptions. We also found that ex situ initiatives (i.e., research/documentation and policy/legislation efforts) are predominant, despite the challenges they reportedly face. These findings call for re-formulating the ways in which ex situ ILK conservation is done and for supporting in situ and IT based initiatives, as they offer the potential to lead the participatory turn.

Status determinants, social incongruity and economic transition: Gender, relative material wealth and heterogeneity in the cultural lifestyle of forager-horticulturalists

For small-scale societies, transitions from self-sufficiency to cash-based labor in market economies have been associated with the exacerbation of existing, and the emergence of new, social incongruities. Social incongruity occurs when two or more of a person’s status determinants (e.g. age, gender, wealth) conflict, resulting in reduced social status. A central focus of theory and research on social incongruity is the relationship between the cultural prototype of what is needed to live a good life–or lifestyle–and status determinants. Assessment of status determinants is challenging because of their relative nature at multiple levels of analysis. This study uses theory and methods from cognitive anthropology to investigate whether and how individual knowledge of a cultural lifestyle prototype conflicts with status determinants at two levels of economic transition among 101 adults from a small-scale society of forager-horticulturalists in Bolivian Amazonia, the Tsimane’. Results support cultural consensus in a 38-item model labeled market lifestyle (explaining 72.7% of sample variance). While the model includes both overlapping traditional (e.g. weaving) and market-related (e.g. education) items and behaviors, most market alternatives were rated higher. When market lifestyle was tested for social incongruity against other status determinants, only gender predicted variation. Thematically, when lifestyle was stratified by gender, men rated several items of relational wealth higher than women did. Analysis of model residual agreement revealed heterogeneity in the form of a syncretic lifestyle model (explaining 18.2% of additional variance). Participants whose knowledge better matched syncretic lifestyle rated traditional items and market alternatives closer to parity. Agreement with the syncretic model correlated with lower material wealth and less market integration. In sum, the findings document a modern, market-oriented form of Tsimane’ lifestyle that varies ontologically from past modelling and ethnographic accounts in preferred forms of livelihood and wealth.

Different patterns in medicinal plant use along an elevational gradient in northern Peruvian Andes

ETHNOPHARMACOLOGICAL RELEVANCE

Through the study of mestizo people that share a common culture in a large geographic region and where traditional knowledge (TK) is still poorly documented, we compared medicinal plant use in the northern Andes of Peru.

AIMS OF THE STUDY

(1) To compare patterns of the distribution of TK for a human group living between two ecoregions: high tropical montane forests vs. low tropical montane forests; (2) to understand the TK at the gender level; and (3) to analyse TK transmission over five generations.

MATERIAL AND METHODS

The study was conducted in two ecoregions, four areas and 12 localities. We gathered information with 600 participants through semi-structured interviews. We worked with 3-7 expert informants per locality using the "walk in the woods" methodology for gathering ethnomedicinal information in the field. We annotated local vernacular names, medicinal indications, and collected the plants in their habitats. Then we interviewed the rest of the participants in their homes. To evaluate significant differences between highlands and lowlands, we use general mixed linear models test and its corresponding post hoc LSD Fisher test of multiple comparisons (p < 0.05) at ecoregion, gender and generation level.

RESULTS

A total of 416 species belonging to 107 plant families and 13,898 use-reports were found in both ecoregions. Overall, significant differences indicated that people in the highlands had higher TK than people in the lowlands for most of the medicinal categories. Women showed higher knowledge on medicinal plants in all medicinal categories and areas in both ecoregions. However, transmission of TK showed different patterns between ecoregions. In the highlands, the TK increased from the youngest to the senior group (51-60 years), with a slight decreasing for those over 60 years, whereas in the lowlands the findings were less clear and generations with highest TK were divergent across localities.

CONCLUSION

TK on medicinal plants is still widely applied in the tropical montane forests of northern Peru. The localities with less prosperous socioeconomic development (highlands) were the areas with higher TK on medicinal plants. Women are mainly the depositories of the traditional medicine. The older generations maintain most of the TK in the highlands, whereas in the lowlands the TK is more widespread across generations. Future conservation programs on medicinal plants should understand who are the generations depositaries of the TK before dedicate any effort.

Indigenous knowledge networks in the face of global change

Indigenous communities rely extensively on plants for food, shelter, and medicine. It is still unknown, however, to what degree their survival is jeopardized by the loss of either plant species or knowledge about their services. To fill this gap, here we introduce indigenous knowledge networks describing the wisdom of indigenous people on plant species and the services they provide. Our results across 57 Neotropical communities show that cultural heritage is as important as plants for preserving indigenous knowledge both locally and regionally. Indeed, knowledge networks collapse as fast when plant species are driven extinct as when cultural diffusion, either within or among communities, is lost. But it is the joint loss of plant species and knowledge that erodes these networks at a much higher rate. Our findings pave the road toward integrative policies that recognize more explicitly the inseparable links between cultural and biological heritage.

Traditional lifestyles, transition, and implications for healthy aging: An Example from the remote island of Pohnpei, Micronesia

Lifestyle-related, non-communicable diseases, such as diabetes, hypertension, and obesity have become critical concerns in the Pacific islands of Micronesia. We investigated the relationship between the diminution of traditional lifestyle practices and the decline in the health of the population in the State of Pohnpei, Federated States of Micronesia. To assess this, our interdisciplinary team developed two scales, one to rank individuals on how traditional their lifestyles were and one to rank individuals on the healthiness of their lifestyles. Participants’ locations were categorized as living on a remote atoll, living on the main island, or as a transitional population. Pohnpeians living in transitional communities (e.g. recently moved from a remote atoll to the main island, or the reverse) ranked lowest on both the tradition and health scales, rather than ranking intermediate between the remote and main island groups as we had hypothesized. As predicted, individuals residing on the remote atolls were living the most traditional lifestyles and also had the healthiest lifestyles, based on our rating system. The higher an individual scored on the tradition scale, e.g. the more traditional life they lived, the higher they scored on the health scale, suggesting the importance of traditional lifestyle practices for maintaining health. These findings have significant implications for promoting health and longevity of Micronesians and other Pacific Island peoples. We suggest the process of transition be recognized as a significant lifestyle and health risk and be given the attention we give to other risk factors that negatively influence our health. Based on our findings, we discuss and recommend the revitalization of particular traditional lifestyle practices, which may advance healthy aging among Pohnpeians.

Maternal experiences of intimate partner violence and C-reactive protein levels in young children in Tanzania

Intimate partner violence (IPV) is a critical public health issue that impacts women and children across the globe. Prior studies have documented that maternal experiences of IPV are associated with adverse psychological and physical health outcomes in children; however, research on the underlying physiological pathways linking IPV to these conditions is limited. Drawing on data from the 2010 Tanzania Demographic and Health Survey, we examined the relationship between maternal report of IPV in the past 12 months and inflammation among children ages 6 months to 5 years. Our study included 503 children who were randomly selected to provide a blood sample and had a mother who had ever been married and who had completed the Domestic Violence Module, which collected information on physical, sexual, and emotional violence. Analyses were stratified based on a threshold for acute immune activation status, defined by the threshold of CRP > 1.1 mg/L for young children in Tanzania. In bivariate analyses, healthy children whose mothers reported IPV showed a marginally elevated median CRP level compared to children whose mothers did not report IPV (0.35 vs. 0.41 mg/L; p = 0.13). Similarly, among children with active or recent infections, those whose mothers reported IPV had an elevated median CRP compared to children whose mothers did not (4.06 vs 3.09 mg/L; p = 0.03). In adjusted multiple variable regression models to account for child, mother, and household characteristics, maternal IPV was positively associated with (log) CRP in both healthy children and children with active or recent infection. Although longitudinal research with additional biomarkers of inflammation is needed, our results provide support for the hypothesis that inflammation may function as a biological pathway linking maternal IPV to poor psychological and physical health outcomes among children of mothers who are victimized-and this may extend to very young children and children in non-Western contexts.

Community factors associated with stunting, overweight and food insecurity: a community-based mixed-method study in four Andean indigenous communities in Ecuador

OBJECTIVES

We aimed to implement participatory research to answer a question posed by four Kichwa indigenous communities in Andean Ecuador about what actionable factors are associated with childhood stunting, overweight and food insecurity among their people.

DESIGN

We used mixed methods including household questionnaires, discussion groups with respondents of the questionnaires and anthropometric measurement of children (6 months to 12 years) from surveyed households.

SETTING

The study involved four Andean indigenous communities transitioning from traditional to Western lifestyles. They subsist mainly on small-scale agriculture and have a rich cultural heritage including their traditional language.

PARTICIPANTS

Anthropometric data were collected from 298 children from 139 households in four communities; all households completed the questionnaire. We held five discussion groups (6-10 participants each): three composed of mothers and two of farmers.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcomes were stunting, overweight, food insecurity and their relationship with demographics, dietary habits and agricultural habits.

RESULTS

Of 298 children, 48.6% were stunted and 43.3% overweight for age. Stunted children were more likely to live in households that sold livestock (ORa 1.77, 95% CIa 1.06 to 2.95) and with illiterate primary caretakers (ORa 1.81, 95% CIa 1.07 to 3.06), but were less likely to live in households with irrigation (ORa 0.47, 95% CIa 0.27 to 0.81). Overweight children were more likely to be male (ORa 1.87, 95% CIa 1.02 to 3.43) and live in a household that sold livestock (ORa 2.14, 95% CIa 1.14 to 4.02). Some 67.8% of children lived in a household with food insecurity, more frequently in those earning below minimum wage (ORa 2.90, 95% CIa 1.56 to 5.41) and less frequently in those that ate quinoa in the past 24 hours (ORa 0.17, 95% CIa 0.06 to 0.48). Discussion groups identified irrigation and loss of agricultural and dietary traditions as important causes of poor childhood nutrition.

CONCLUSION

Many indigenous communities face tumultuous cultural, nutritional and epidemiological transitions. Community-based interventions on factors identified here could mitigate negative health outcomes.

Birth seasons and heights among girls and boys below 12 years of age: lasting effects and catch-up growth among native Amazonians in Bolivia

BACKGROUND

Seasons affect many social, economic, and biological outcomes, particularly in low-resource settings, and some studies suggest that birth season affects child growth.

AIM

To study a predictor of stunting that has received limited attention: birth season.

SUBJECTS AND METHODS

This study uses cross-sectional data collected during 2008 in a low-resource society of horticulturists-foragers in the Bolivian Amazon, Tsimane'. It estimates the associations between birth months and height-for-age Z-scores (HAZ) for 562 girls and 546 boys separately, from birth until age 11 years or pre-puberty, which in this society occurs ∼13-14 years.

RESULTS

Children born during the rainy season (February-May) were shorter, while children born during the end of the dry season and the start of the rainy season (August-November) were taller, both compared with their age-sex peers born during the rest of the year. The correlations of birth season with HAZ were stronger for boys than for girls. Controlling for birth season, there is some evidence of eventual partial catch-up growth, with the HAZ of girls or boys worsening until ∼ age 4-5 years, but improving thereafter. By age 6 years, many girls and boys had ceased to be stunted, irrespective of birth season.

CONCLUSION

The results suggest that redressing stunting will require attention to conditions in utero, infancy and late childhood.

Conditional cash transfers for primary education: Which children are left out?

Conditional cash transfer (CCT) programs to increase primary-school enrollment and attendance among low-income households have been shown to benefit children and households, but to date little is known about who joins such programs. We test three hypotheses about predictors of CCT program participation in indigenous societies in Bolivia, focusing on attributes of the household (ethnicity), parents (modern human capital), and children (age, sex). We model whether children receive a transfer from Bolivia's CCT program (Bono Juancito Pinto), using data from 811 school-age children and nine ethnic groups. Children from the group least exposed to Westerners (Tsimane') are 18-22 percentage points less likely to participate in the program than children from other lowland ethnic groups. Parental modern human capital and child sex do not predict participation. We discuss possible mechanisms underlying the findings and conclude that the Tsimane's current lower returns to schooling are the most likely explanation.

Economic and demographic predictors of dietary variation and nutritional indicators in Nicaragua

OBJECTIVES

We measured carbon and nitrogen isotopic ratios in a contemporary population, and tested how the isotopic variability relates to measures of socioeconomic status (e.g., household wealth) and anthropometric measures (e.g., standardized height-for-age and weight-for-age z-scores).

METHODS

Hair samples from individuals living in the Bosawas Biosphere Reserve in Nicaragua were analyzed for δ¹³ C and δ¹⁵ N, and these data were examined in relation to individual (e.g., age, sex, anthropometrics) and household (e.g., household size, wealth) variables.

RESULTS

We found through mixed-effects modeling that δ¹³ C and δ¹⁵ N varied predictably with individual age and household wealth. δ¹³ C and δ¹⁵ N did not, however, improve models predicting variation in individual anthropometric measures.

CONCLUSION

These results indicate that, although there is a relationship between diet (δ¹³ C and δ¹⁵ N) and socioeconomic variables, these dietary differences are not the main cause of health differences in this population.

Child stunting is associated with weaker human capital among native Amazonians

OBJECTIVES

We assessed associations between child stunting, recovery, and faltering with schooling and human capital skills in a native Amazonian society of horticulturalists-foragers (Tsimane').

METHODS

We used cross-sectional data (2008) from 1262 children aged 6 to 16 years in 53 villages to assess contemporaneous associations between three height categories: stunted (height-for-age Z score, HAZ<-2), moderately stunted (-2 ≤ HAZ≤-1), and nonstunted (HAZ>-1), and three categories of human capital: completed grades of schooling, test-based academic skills (math, reading, writing), and local plant knowledge. We used annual longitudinal data (2002-2010) from all children (n = 853) in 13 villages to estimate the association between changes in height categories between the first and last years of measure and schooling and academic skills.

RESULTS

Stunting was associated with 0.4 fewer completed grades of schooling (∼24% less) and with 13-15% lower probability of showing any writing or math skills. Moderate stunting was associated with ∼20% lower scores in local plant knowledge and 9% lower probability of showing writing skills, but was not associated with schooling or math and writing skills. Compared with nonstunted children, children who became stunted had 18-21% and 15-21% lower probabilities of showing math and writing skills, and stunted children had 0.4 fewer completed grades of schooling. Stunted children who recovered showed human capital outcomes that were indistinguishable from nonstunted children.

CONCLUSIONS

The results confirm adverse associations between child stunting and human capital skills. Predictors of growth recovery and faltering can affect human capital outcomes, even in a remote, economically self-sufficient society.

Antibacterial activities of medicinal plants used in Mexican traditional medicine

ETHNOPHARMACOLOGICAL RELEVANCE

We provide an extensive summary of the in vitro antibacterial properties of medicinal plants popularly used in Mexico to treat infections, and we discuss the ethnomedical information that has been published for these species.

MATERIALS AND METHODS

We carried out a bibliographic investigation by analyzing local and international peer-reviewed papers selected by consulting internationally accepted scientific databases from 1995 to 2014. We provide specific information about the evaluated plant parts, the type of extracts, the tested bacterial strains, and the inhibitory concentrations for each one of the species. We recorded the ethnomedical information for the active species, as well as their popular names and local distribution. Information about the plant compounds that has been identified is included in the manuscript. This review also incorporates an extensive summary of the available toxicological reports on the recorded species, as well as the worldwide registries of plant patents used for treating bacterial infections. In addition, we provide a list with the top plant species with antibacterial activities in this review RESULTS: We documented the in vitro antibacterial activities of 343 plant species pertaining to 92 botanical families against 72 bacterial species, focusing particularly on Staphylococcus aureus, Mycobacterium tuberculosis, Escherichia coli and Pseudomonas aeruginosa. The plant families Asteraceae, Fabaceae, Lamiaceae and Euphorbiaceae included the largest number of active species. Information related to popular uses reveals that the majority of the plants, in addition to treating infections, are used to treat other conditions. The distribution of Mexican plants extended from those that were reported to grow in just one state to those that grow in all 32 Mexican states. From 75 plant species, 225 compounds were identified. Out of the total plant species, only 140 (40.57%) had at least one report about their toxic effects. From 1994 to July 2014 a total of 11,836 worldwide antibacterial patents prepared from different sources were recorded; only 36 antibacterial patents from plants were registered over the same time period. We offered some insights on the most important findings regarding the antibacterial effects, current state of the art, and research perspectives of top plant species with antibacterial activities in vitro.

CONCLUSIONS

Studies of the antibacterial in vitro activity of medicinal plants popularly used in Mexico to treat infections indicate that both the selection of plant material and the investigation methodologies vary. Standardized experimental procedures as well as in vivo pharmacokinetic studies to document the effectiveness of plant extracts and compounds are necessary. This review presents extensive information about the medicinal plants possessing antibacterial activity that has been scientifically studied and are popularly used in Mexico. We anticipate that this review will be of use for future studies because it constitutes a valuable information tool for selecting the most significant plants and their potential antibacterial properties.

Multilevel processes and cultural adaptation: Examples from past and present small-scale societies

Cultural adaptation has become central in the context of accelerated global change with authors increasingly acknowledging the importance of understanding multilevel processes that operate as adaptation takes place. We explore the importance of multilevel processes in explaining cultural adaptation by describing how processes leading to cultural (mis)adaptation are linked through a complex nested hierarchy, where the lower levels combine into new units with new organizations, functions, and emergent properties or collective behaviours. After a brief review of the concept of "cultural adaptation" from the perspective of cultural evolutionary theory and resilience theory, the core of the paper is constructed around the exploration of multilevel processes occurring at the temporal, spatial, social and political scales. We do so by examining small-scale societies' case studies. In each section, we discuss the importance of the selected scale for understanding cultural adaptation and then present an example that illustrates how multilevel processes in the selected scale help explain observed patterns in the cultural adaptive process. We end the paper discussing the potential of modelling and computer simulation for studying multilevel processes in cultural adaptation.

Gendered medicinal plant knowledge contributions to adaptive capacity and health sovereignty in Amazonia

Local medical systems are key elements of social-ecological systems as they provide culturally appropriate and locally accessible health care options, especially for populations with scarce access to biomedicine. The adaptive capacity of local medical systems generally rests on two pillars: species diversity and a robust local knowledge system, both threatened by local and global environmental change. We first present a conceptual framework to guide the assessment of knowledge diversity and redundancy in local medicinal knowledge systems through a gender lens. Then, we apply this conceptual framework to our research on the local medicinal plant knowledge of the Tsimane' Amerindians. Our results suggest that Tsimane' medicinal plant knowledge is gendered and that the frequency of reported ailments and the redundancy of knowledge used to treat them are positively associated. We discuss the implications of knowledge diversity and redundancy for local knowledge systems' adaptive capacity, resilience, and health sovereignty.

Knowledge-Sharing Networks in Hunter-Gatherers and the Evolution of Cumulative Culture

Humans possess the unique ability for cumulative culture [1, 2]. It has been argued that hunter-gatherer's complex social structure [3-9] has facilitated the evolution of cumulative culture by allowing information exchange among large pools of individuals [10-13]. However, empirical evidence for the interaction between social structure and cultural transmission is scant [14]. Here we examine the reported co-occurrence of plant uses between individuals in dyads (which we define as their "shared knowledge" of plant uses) in BaYaka Pygmies from Congo. We studied reported uses of 33 plants of 219 individuals from four camps. We show that (1) plant uses by BaYaka fall into three main domains: medicinal, foraging, and social norms/beliefs; (2) most medicinal plants have known bioactive properties, and some are positively associated with children's BMI, suggesting that their use is adaptive; (3) knowledge of medicinal plants is mainly shared between spouses and biological and affinal kin; and (4) knowledge of plant uses associated with foraging and social norms is shared more widely among campmates, regardless of relatedness, and is important for camp-wide activities that require cooperation. Our results show the interdependence between social structure and knowledge sharing. We propose that long-term pair bonds, affinal kin recognition, exogamy, and multi-locality create ties between unrelated families, facilitating the transmission of medicinal knowledge and its fitness implications. Additionally, multi-family camps with low inter-relatedness between camp members provide a framework for the exchange of functional information related to cooperative activities beyond the family unit, such as foraging and regulation of social life.

An ethnomedicinal survey of a Tashelhit-speaking community in the High Atlas, Morocco

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional knowledge about medicinal plants from a poorly studied region, the High Atlas in Morocco, is reported here for the first time; this permits consideration of efficacy and safety of current practises whilst highlighting species previously not known to have traditional medicinal use.

AIM OF THE STUDY

Our study aims to document local medicinal plant knowledge among Tashelhit speaking communities through ethnobotanical survey, identifying preferred species and new medicinal plant citations and illuminating the relationship between emic and etic ailment classifications.

MATERIALS AND METHODS

Ethnobotanical data were collected using standard methods and with prior informed consent obtained before all interactions, data were characterized using descriptive indices and medicinal plants and healing strategies relevant to local livelihoods were identified.

RESULTS

151 vernacular names corresponding to 159 botanical species were found to be used to treat 36 folk ailments grouped in 14 biomedical use categories. Thirty-five (22%) are new medicinal plant records in Morocco, and 26 described as used for the first time anywhere. Fidelity levels (FL) revealed low specificity in plant use, particularly for the most commonly reported plants. Most plants are used in mixtures. Plant use is driven by local concepts of disease, including "hot" and "cold" classification and beliefs in supernatural forces.

CONCLUSION

Local medicinal plant knowledge is rich in the High Atlas, where local populations still rely on medicinal plants for healthcare. We found experimental evidence of safe and effective use of medicinal plants in the High Atlas; but we highlight the use of eight poisonous species.

Heterogeneous effects of market integration on sub-adult body size and nutritional status among the Shuar of Amazonian Ecuador

BACKGROUND

Market integration (MI)-increasing production for and consumption from a market-based economy-is drastically altering traditional ways of life and environmental conditions among indigenous Amazonian peoples. The effects of MI on the biology and health of Amazonian children and adolescents, however, remain unclear.

AIM

This study examines the impact of MI on sub-adult body size and nutritional status at the population, regional and household levels among the Shuar of Amazonian Ecuador.

SUBJECTS AND METHODS

Anthropometric data were collected between 2005-2014 from 2164 Shuar (aged 2-19 years) living in two geographic regions differing in general degree of MI. High-resolution household economic, lifestyle and dietary data were collected from a sub-sample of 631 participants. Analyses were performed to investigate relationships between body size and year of data collection, region and specific aspects of household MI.

RESULTS

Results from temporal and regional analyses suggest that MI has a significant and overall positive impact on Shuar body size and nutritional status. However, household-level results exhibit nuanced and heterogeneous specific effects of MI underlying these overarching relationships.

CONCLUSION

This study provides novel insight into the complex socio-ecological pathways linking MI, physical growth and health among the Shuar and other indigenous Amazonian populations.

Medicinal plants at Rio Jauaperi, Brazilian Amazon: Ethnobotanical survey and environmental conservation

STUDY BACKGROUND

The Amazon basin is a mosaic of different environments. Flooded riparian and upland forests play a significant role for the establishment of human settlements. Riparian communities in the Amazon have evolved depending on the use of plants applied for therapeutic purposes, thus developing important knowledge about their management and preparation.

AIM OF THE STUDY

This paper describes and analyzes the use and management of medicinal plants in order to establish links to environmental conservation. The categorization of habitats of occurrence and categories of diseases were held in five riparian communities at Rio Jauaperi, in the border between Roraima and Amazonas states in Brazil. The study sight is poorly investigated in terms of scientific research.

MATERIALS AND METHODS

Quantitative and qualitative ethnobotanical field inquiries and analytical methods including observations, individual and focus group discussions, individual interviews, preference ranking by free listing tasks, guided tours and community mapping were applied. Sutrop's cognitive salience index was applied in order to check the most important ethnospecies and diseases. The survey was conducted from February to December 2012.

RESULTS

A total of 62 informants were interviewed, resulting in 119 botanical species documented. The most salient medicinal species are usually wide distributed and recognized transculturally. Arboreal habit was the most important corresponding to 47% of total species used. The most frequent accessed environments were terra-firme (upland forest), vargeado (flooded forest), poultry (regenerating forest) and restinga (seasonally flooded forest) which together provides 59% of the total medicinal plant species. Exotic species played a secondary role with only 20% of the total. Thirty seven percent of the species were cultivated. Plants at homegardens are usually associated with children's or women's disease. Xixuaú is the community with improved ability to environmental preservation using more forestry species. The most worrying disease was malaria. Biomedical assistance is precarious in the region and many diseases and healing rituals are culturally built.

CONCLUSIONS

Ethnobotanical surveys of medicinal plants can indicate the level of biodiversity conservation and human health by integrating social and ecological analytical elements. Considering a predominance of management for subsistence, the higher richness of native medicinal species availability indicates that biodiversity and associated traditional knowledge are better preserved. The methods applied here might contribute for the decision-making process regarding conservation public policies and medical assistance in remote areas of the Amazon basin.

Schooling, Local Knowledge and Working Memory: A Study among Three Contemporary Hunter-Gatherer Societies

Researchers have analysed whether school and local knowledge complement or substitute each other, but have paid less attention to whether those two learning models use different cognitive strategies. In this study, we use data collected among three contemporary hunter-gatherer societies with relatively low levels of exposure to schooling yet with high levels of local ecological knowledge to test the association between i) schooling and ii) local ecological knowledge and verbal working memory. Participants include 94 people (24 Baka, 25 Punan, and 45 Tsimane’) from whom we collected information on 1) schooling and school related skills (i.e., literacy and numeracy), 2) local knowledge and skills related to hunting and medicinal plants, and 3) working memory. To assess working memory, we applied a multi-trial free recall using words relevant to each cultural setting. People with and without schooling have similar levels of accurate and inaccurate recall, although they differ in their strategies to organize recall: people with schooling have higher results for serial clustering, suggesting better learning with repetition, whereas people without schooling have higher results for semantic clustering, suggesting they organize recall around semantically meaningful categories. Individual levels of local ecological knowledge are not related to accurate recall or organization recall, arguably due to overall high levels of local ecological knowledge. While schooling seems to favour some organization strategies this might come at the expense of some other organization strategies.

The Tsimane' Amazonian Panel Study (TAPS): Nine years (2002-2010) of annual data available to the public

This brief communication contains a description of the 2002-2010 annual panel collected by the Tsimane' Amazonian Panel Study team. The study took place among the Tsimane', a native Amazonian society of forager-horticulturalists. The team tracked a wide range of socio-economic and anthropometric variables from all residents (633 adults ≥16 years; 820 children) in 13 villages along the Maniqui River, Department of Beni. The panel is ideally suited to examine how market exposure and modernization affect the well-being of a highly autarkic population and to examine human growth in a non-Western rural setting.

The adaptive nature of culture. A cross-cultural analysis of the returns of local environmental knowledge in three indigenous societies

Researchers have argued that the behavioral adaptations that explain the success of our species are partially cultural, i.e., cumulative and socially transmitted. Thus, understanding the adaptive nature of culture is crucial to understand human evolution. We use a cross-cultural framework and empirical data purposely collected to test whether culturally transmitted and individually appropriated knowledge provides individual returns in terms of hunting yields and health and, by extension, to nutritional status, a proxy for individual adaptive success. Data were collected in three subsistence-oriented societies: the Tsimane' (Amazon), the Baka (Congo Basin), and the Punan (Borneo). Results suggest that variations in individual levels of local environmental knowledge relate to individual hunting returns and to self-reported health, but not to nutritional status. We argue that this paradox can be explained through the prevalence of sharing: individuals achieving higher returns to their knowledge transfer them to the rest of the population, which explains the lack of association between knowledge and nutritional status. The finding is in consonance with previous research highlighting the importance of cultural traits favoring group success, but pushes it forward by elucidating the mechanisms through which individual and group level adaptive forces interact.