The cultural ecology of dietary change accompanying changing activity patterns among the shipibo

Shipibo Indians, who formed a village to establish a school and health clinic, are gradually depleting local fish and game resources. Men, recently adopting rice as a cash crop, tend to fish and hunt less than other men working only their subsistence gardens. Sale of fish and game in the village is becoming common, and pigs, once raised exclusively for sale to non-Shipibo, are now more regularly eaten and used for attracting agricultural labor. Other research has indicated that cash cropping often competes for workers' time in subsistence and so dietary change usually accompanies changing activity patterns. This paper explores the latter possibility by examining the relationship between cash cropping, wild meat procurement, and diet among the Shipibo. Time allocation and food consumption data are analyzed statistically to test a mathematical theory and model which relates indigenous work patterns to diet.     

Labor specialization and the formation of markets for food in a Shipibo subsistence economy

Traditionally, the Shipibo economy was subsistence-based with shifting cultivation supplying calories, principally in the form of plantains and root crops, while fishing and hunting provided animal proteins to the diet. Some men, who recently began producing rice for sale in regional markets, now allocate less time to wild food procurement. Moreover, this trend has been accompanied by the nucleation of households, a growing cash market for agricultural labor, and the intravillage sale of faunal foods. This paper shows that with cash cropping, some Shipibo now freely distribute less food to others in relation to the amount they produce. To account for this change, a theory is developed based on time allocation and patterns of economic behavior reported throughout the Amazon. This theory is then applied to explain specialization and the formation of cash markets for food labor among the Shipibo.     

Art and Residence Among the Shipibo Indians of Peru: A Study in Microacculturation

The geometric decorative art of the Shipibo Indians, Peruvian montaña, is produced by women balanced between a cultural imperative for personal innovation and submission to the constraints of traditional style. The experimental commissioning of painted Shipibo textile samplers using a rule-based approach reveals that additional variables in the Deetz-Longacre hypothesis associating female stylistic uniformity with matrilineal descent and matrilocal residence, such as the number of elements and rules used and the higher position in a hierarchy of complexity such solutions occupy, contribute to aesthetic micro-acculturation. That is done in the Shipibo case in a way that belies the presupposition that the mother is always the most important mentor in a girl's art, while supporting this archaeological theory's prediction that a group of coresiding females produces relatively homogeneous art. [ethnoarchaeology, art-style analysis, Deetz-Longacre hypothesis, South American Indians, Peru, Shipibo]     

Early paleolithic of China and eastern Asia

In attempting to understand the course of human evolution and the nature of hominid adaptation over the past few million years, it is necessary to consider prevailing evidence from all parts of the world. Eastern Asia provides a range of important questions and challenges with regard to this evolutionary puzzle. Although evidence for earlier ape evolution is present in China (for example, at Lufeng in Yunnan Province), the earliest evidence for hominid presence appears to be in the Early Pleistocene, apparently the result of a migration of hominids to and subsequent adaptation within Eastern Asia. The archeological record provides a closer look at some technological aspects of this adaptation during the Early and Middle Pleistocene, showing both distinctive contrasts and intriguing continuities relative to the rest of the Old World.     

The effects of tourist and boat traffic on parrot geophagy in lowland Peru

Ecotourism generates important revenue in many developing economies, but poorly regulated ecotourism can threaten the long‐term viability of key biological resources. We determined the effects of tourism, boat traffic, and natural disturbances on parrot geophagy (soil consumption) across seven riverine claylicks in the lowlands of Madre de Dios, Peru. Claylick use significantly decreased when visitors did not follow good practice guidelines and tourist numbers exceeded the capacity of the observation blinds. Otherwise, tourist presence and natural disturbance did not have a significant effect. However, large macaws, particularly Red‐and‐green Macaws (Ara chloropterus), avoided visiting claylicks during periods of peak tourist numbers. Where parrots had multiple geophagy sites to choose from, they preferred sites further from tourist groups. The effect of boat disturbance was greatest on a narrow river with infrequent boat events. On a wider river with heavier traffic, boat disturbance had less of an effect and this effect was inversely proportional to the distance of boats from the claylick. Where visitors followed good‐practice tourism guidelines, they had a low overall negative effect on parrot geophagy. We recommend that visitors respect the claylick observation guidelines to minimize anthropogenic disturbance on parrots and maintain these sites for the benefit of wildlife and humans alike.     

Age-dependency in hunting ability among the Ache of eastern Paraguay

This paper examines changes in hunting ability across the lifespan for the Ache of eastern Paraguay. Hunting ability is decomposed into two components-finding prey and probability of kill upon encounter- and analyzed for important prey species. Results support the argument that skill acquisition is an important aspect of the human foraging niche with hunting outcome variables reaching peaks surprisingly late in life, significantly after peaks in strength. The implications of this study are important for modeling the role of the human foraging niche in the co-evolution of various outstanding human life history characteristics such as large brains, long lifespans, and extended juvenile periods.     

Cooperation and conflict between women in the family

Here I review recent research on reproductive conflict between females in families and how it influences their reproductive behaviour. Kin selection can favor cooperation between parent and offspring, siblings, or unrelated co‐residents who share interests in other family members such as grand‐offspring. However, these are also the individuals most likely to be sharing resources, and so conflict can also emerge. While substantial interest has arisen in evolutionary anthropology, especially over the last two decades, in the possibility of cooperative breeding in humans, less attention has been paid to reproductive conflict among female kin. Communal breeding in animals is generally understood as emerging from competition over the resources needed to breed. Competition for household resources is a problem that also faces human families. Models suggest that in some circumstances, inclusive fitness can be maximized by sharing reproduction rather than harming relatives by fighting with them, even if the shares that emerge are not equal. Thus, competition and cooperation turn out to be strongly related to each other. Reproductive competition within and between families may have underpinned the biological evolution of fertility patterns (such as menopause) and the cultural evolution of marriage, residence, and inheritance norms (such as late male marriage or primogeniture), which can enhance cooperation and minimize the observed incidence of such conflicts.     

Global distribution and drivers of language extinction risk

Many of the world''s languages face serious risk of extinction. Efforts to prevent this cultural loss are severely constrained by a poor understanding of the geographical patterns and drivers of extinction risk. We quantify the global distribution of language extinction risk—represented by small range and speaker population sizes and rapid declines in the number of speakers—and identify the underlying environmental and socioeconomic drivers. We show that both small range and speaker population sizes are associated with rapid declines in speaker numbers, causing 25% of existing languages to be threatened based on criteria used for species. Language range and population sizes are small in tropical and arctic regions, particularly in areas with high rainfall, high topographic heterogeneity and/or rapidly growing human populations. By contrast, recent speaker declines have mainly occurred at high latitudes and are strongly linked to high economic growth. Threatened languages are numerous in the tropics, the Himalayas and northwestern North America. These results indicate that small-population languages remaining in economically developed regions are seriously threatened by continued speaker declines. However, risks of future language losses are especially high in the tropics and in the Himalayas, as these regions harbour many small-population languages and are undergoing rapid economic growth.     

Cultural transmission and the evolution of human behaviour: a general approach based on the Price equation

Transmitted culture can be viewed as an inheritance system somewhat independent of genes that is subject to processes of descent with modification in its own right. Although many authors have conceptualized cultural change as a Darwinian process, there is no generally agreed formal framework for defining key concepts such as natural selection, fitness, relatedness and altruism for the cultural case. Here, we present and explore such a framework using the Price equation. Assuming an isolated, independently measurable culturally transmitted trait, we show that cultural natural selection maximizes cultural fitness, a distinct quantity from genetic fitness, and also that cultural relatedness and cultural altruism are not reducible to or necessarily related to their genetic counterparts. We show that antagonistic coevolution will occur between genes and culture whenever cultural fitness is not perfectly aligned with genetic fitness, as genetic selection will shape psychological mechanisms to avoid susceptibility to cultural traits that bear a genetic fitness cost. We discuss the difficulties with conceptualizing cultural change using the framework of evolutionary theory, the degree to which cultural evolution is autonomous from genetic evolution, and the extent to which cultural change should be seen as a Darwinian process. We argue that the nonselection components of evolutionary change are much more important for culture than for genes, and that this and other important differences from the genetic case mean that different approaches and emphases are needed for cultural than genetic processes.     

Divergence and evolution of reproductive barriers among three allopatric populations of Rhagoletis cingulata across eastern North America and Mexico

Geography is often a key factor facilitating population divergence and speciation. In this regard, the geographic distributions of flies in the genus Rhagoletis (Diptera: Tephritidae) in temperate North America have been affected by cycles of Pleistocene glaciation and interglacial periods. Fluctuations in climatic conditions may have had their most dramatic effects on geographically isolating Rhagoletis flies in the central highland region of Mexico. During past periods of allopatry, a degree of post‐zygotic reproductive isolation appears to have evolved between hawthorn‐infesting populations of Rhagoletis pomonella (Walsh) in the central Eje Volcanico Trans Mexicano (EVTM) and those from the Sierra Madre Oriental Mountains (SMO) of Mexico, as well as hawthorn flies from the eastern USA. Here, we investigate the generality of this finding in the genus Rhagoletis by testing for reproductive isolation among populations of Rhagoletis cingulata (Loew) (Diptera: Tephritidae) collected from infested domesticated sweet cherry (Prunus avium L.) in the USA and black cherry [Prunus serotina Ehrh. (both Rosaceae)] from the SMO and EVTM. We report evidence for marked post‐mating reproductive isolation among certain R. cingulata populations. The high levels of reproductive isolation were observed between R. cingulata flies from populations in the USA and SMO differed from the pattern seen for R. pomonella, primarily involving the EVTM. In addition, egg hatch was significantly reduced for crosses between SMO males and EVTM females, but not greatly in the opposite direction. We discuss potential causes for the different patterns of post‐mating reproductive isolation among Rhagoletis flies.     

Settler agriculture and the dynamics of resource allocation in frontier environments

This article attempts to conceptualize the dynamics of resource allocation by colonist farmers under the unique conditions of land abundance and labor scarcity which characterize frontier environments, such as the smallholder agricultural settlement areas in the Amazon basin. In contrast, most previous theoretical literature on household agricultural decision making and land-use change in rural areas considers conditions of high population density and land scarcity, and is not, therefore, adequate for understanding critical land-use changes which may be occurring in frontier regions. This article first discusses the appropriateness and inadequacies of the analytical frameworks commonly used to explain the expansion of settler agriculture into remote forest regions and the unsustainable land-use practices observed in these areas. This review serves as the basis for characterizing resource allocation under the particular conditions of frontier environments. A conceptual advance in the analysis is its consideration of the way institutional/policy factors and farm-level characteristics can interact to produce land-use outcomes. This knowledge is essential to understand not only the social and economic factors affecting present land use and choice of technology, but also those factors influencing farmers' demand for more optimal systems of land use which are consistent with varying agro-ecological potentials, demographic situations, and their own management capacity.     

The role of causal knowledge in the evolution of traditional technology

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Genetic diversity and genomic signatures of selection among cattle breeds from Siberia,eastern and northern Europe

Domestication in the near eastern region had a major impact on the gene pool of humpless taurine cattle (Bos taurus). As a result of subsequent natural and artificial selection, hundreds of different breeds have evolved, displaying a broad range of phenotypic traits. Here, 10 Eurasian B. taurus breeds from different biogeographic and production conditions, which exhibit different demographic histories and have been under artificial selection at various intensities, were investigated using the Illumina BovineSNP50 panel to understand their genetic diversity and population structure. In addition, we scanned genomes from eight breeds for signatures of diversifying selection. Our population structure analysis indicated six distinct breed groups, the most divergent being the Yakutian cattle from Siberia. Selection signals were shared (experimental P‐value < 0.01) with more than four breeds on chromosomes 6, 7, 13, 16 and 22. The strongest selection signals in the Yakutian cattle were found on chromosomes 7 and 21, where a miRNA gene and genes related to immune system processes are respectively located. In general, genomic regions indicating selection overlapped with known QTL associated with milk production (e.g. on chromosome 19), reproduction (e.g. on chromosome 24) and meat quality (e.g. on chromosome 7). The selection map created in this study shows that native cattle breeds and their genetic resources represent unique material for future breeding.     

Behavioural variation in 172 small-scale societies indicates that social learning is the main mode of human adaptation

The behavioural variation among human societies is vast and unmatched in the animal world. It is unclear whether this variation is due to variation in the ecological environment or to differences in cultural traditions. Underlying this debate is a more fundamental question: is the richness of humans’ behavioural repertoire due to non-cultural mechanisms, such as causal reasoning, inventiveness, reaction norms, trial-and-error learning and evoked culture, or is it due to the population-level dynamics of cultural transmission? Here, we measure the relative contribution of environment and cultural history in explaining the behavioural variation of 172 Native American tribes at the time of European contact. We find that the effect of cultural history is typically larger than that of environment. Behaviours also persist over millennia within cultural lineages. This indicates that human behaviour is not predominantly determined by single-generation adaptive responses, contra theories that emphasize non-cultural mechanisms as determinants of human behaviour. Rather, the main mode of human adaptation is social learning mechanisms that operate over multiple generations.     

On the combined analysis of proximate and ultimate aspects in diel vertical migration (DVM) research

Although evolutionary ecologists agree that proximate and ultimate aspects are two sides of one coin, they are seldom interested in studies on physiological and behavioural mechanisms at the base of ecological phenomena. Nevertheless, these mechanisms are objects of selection and evolved to realise adaptive significances. This paper is a plea to bring both fields closer together, and, by means of an example of Diel Vertical Migration of Daphnia, some proximate and ultimate aspects are discussed. It is argued that light changes, not fish kairomone, is the primary cause for an individual to swim downwards at dawn and upwards at dusk. However, what is called a causal factor might differ when ecosystems or individuals are studied. In addition, causality in ecology is not simple, and has the character of a `set of necessary conditions'. To illustrate the importance of proximate analyses in DVM, two basic response mechanisms are discussed: Photobehaviour system 1 and 2. The physiological character of these systems leads to a fixed type of migration or to a phenotypically induced DVM, respectively. The adaptive significance of the first might be a reduction of the hazardous effects of UV radiation and of the second a lowering of mortality due to visually hunting predators.