Piaroa Manioc Varietals: Hyperdiversity or Social Currency?

The maintenance of exceptionally high numbers of folk varieties by the Piaroa people of the Venezuelan Amazon is considered. We cataloged 113 manioc folk varieties, their nomenclature, use and relevant characters, revealing significant insights into the role of manioc in Piaroa social life. Through a qualitative investigation of the cultivation, processing and symbolic significance of manioc (Manihot esculenta) in two Piaroa regions over a period of 18 years, we have found that such agrobiodiversity can only be fully explained by a combination of multiple factors, including pragmatic and ecological considerations, the subtle and complex diversity of Piaroa manioc preparations and a variety of sociocultural factors, such as manioc’s role as a mediator of social relationships and as a marker of cultural and social heritage.

Livestock Acquisitions Dynamics in Nomadic Pastoralist Herd Demography: A Case Study Among Ngisonyoka Herders of South Turkana, Kenya

Despite the attention given to social relations in the pastoral literature, the role of livestock acquisitions—additions of livestock to herds through bridewealth, exchanges, gifts, payments, and begging (requests)—in herd build up has usually been assumed to be relatively minor compared to births and relevant mostly when the need for rebuilding arises after major losses. This study is based on an unusual set of data—the reproductive histories of the female cattle, camels, and goats and sheep of 13 Ngisonyoka Turkana nomadic herders in northwestern Kenya, collected in 1987. The article reports on the means by which mothers were added to the herd and how these changed through time. The results suggest that for this population in the late 1970s and 1980s, acquisitions were not merely relevant when disaster struck, but instead were a continuously important component of herd management. The results demonstrate the crucial role of social networks in the survival of Ngisonyoka pastoralists in their non-equilibrial ecosystem. Social exchanges, such as bridewealth, provide a resource security well suited to the challenges of coping with such unpredictable environments. Researchers and policymakers are urged to make efforts to support such indigenous networks if they want nomadic pastoralists to continue their effective use of arid, marginal lands.

Amazon Forestry Tranformed: Integrating Knowledge for Smallholder Timber Managemet in Eastern Brazil

Recent discussions of local knowledge emphasize its dynamic nature invoking local peoples’ ability to effectively integrate traditional or local with science-based or “modern” knowledges. The smallholder timber industry of the Amazon’s estuarine floodplain provides an outstanding example of local patterns of resource management and economic activities transformed from within by smallholder farmers who participated in the industrial timber boom of the 1970s and 1980s. These farmers of eastern Amazonia have developed a vertically integrated local industry based on expertise reflecting profound locally developed knowledge of specific forests and management of ecological processes, individual observation and experimentation, as well as concepts and practices derived from temporary employment by large-scale industrial timber firms. At each stage of the smallholder forestry process—from managing natural regeneration to running small sawmills and marketing lumber—local managers apply an innovative set of practices reflecting their diverse experiences. This combination of technical, market, and ecological knowledge results in forests, timber markets, and economic patterns that do not correspond to many of the widely-held generalizations concerning either local or industrial tropical timber exploitation. This article uses data from 7 years of research in the Amazon floodplain.

Evolutionary Trends

The occurrence, generality, and causes of large-scale evolutionary trends—directional changes over long periods of time—have been the subject of intensive study and debate in evolutionary science. Large-scale patterns in the history of life have also been of considerable interest to nonspecialists, although misinterpretations and misunderstandings of this important issue are common and can have significant implications for an overall understanding of evolution. This paper provides an overview of how trends are identified, categorized, and explained in evolutionary biology. Rather than reviewing any particular trend in detail, the intent is to provide a framework for understanding large-scale evolutionary patterns in general and to highlight the fact that both the patterns and their underlying causes are usually quite complex.

Understanding Evolutionary Trees

Charles Darwin sketched his first evolutionary tree in 1837, and trees have remained a central metaphor in evolutionary biology up to the present. Today, phylogenetics—the science of constructing and evaluating hypotheses about historical patterns of descent in the form of evolutionary trees—has become pervasive within and increasingly outside evolutionary biology. Fostering skills in “tree thinking” is therefore a critical component of biological education. Conversely, misconceptions about evolutionary trees can be very detrimental to one’s understanding of the patterns and processes that have occurred in the history of life. This paper provides a basic introduction to evolutionary trees, including some guidelines for how and how not to read them. Ten of the most common misconceptions about evolutionary trees and their implications for understanding evolution are addressed.

Objects limit human comprehension

This paper demonstrates that the human visual system, the primary sensory conduit for primates, processes ambient energy in a way that obligatorily constructs the objects that we ineluctably perceive. And since our perceptual apparatus processes information only in terms of objects (along with the properties and movements of objects), we are limited in our ability to comprehend ‘what is’ when we move beyond our ordinary world of midsize objects—as, for example, when we address the micro microworld of quantum physics.

Assessing the fitness landscape revolution

According to Pigliucci and Kaplan, there is a revolution underway in how we understand fitness landscapes. Recent models suggest that a perennial problem in these landscapes—how to get from one peak across a fitness valley to another peak—is, in fact, non-existent. In this paper I assess the structure and the extent of Pigliucci and Kaplan’s proposed revolution and argue for two points. First, I provide an alternative interpretation of what underwrites this revolution, motivated by some recent work on model-based science. Second, I show that the implications of this revolution need to carefully assessed depending on question being asked, for peak-shifting is not central to all evolutionary questions that fitness landscapes have been used to explore.

Towards Endogenous Livestock Development: Borana Pastoralists’ Responses to Environmental and Institutional Changes

Borana pastoralists in southern Ethiopia are faced with the challenge of developing more efficient and sustainable use of natural resources. In past decades poorly adapted development interventions and inadequate land-use policies aggravated by population growth have weakened pastoral rangeland management. Ignoring pastoralists’ technical and organizational capacities has contributed to progressive land degradation, the erosion of social structures and poverty. The Endogenous Livestock Development concept recognises pastoralists’ indigenous knowledge-based strategies and priorities, and uses them as the bases for further development of their production system and social relations, to be utilized, improved and combined with modern technologies. This paper explores the Borana pastoralists’ adaptive strategies for improved utilization of natural resources and the manner in which they respond to environmental risk and external influences such as water development and new formal administration. The adaptive responses include controlled integration of crop production and protection of grazing reserves, as well as changing cattle breeding priorities and the adoption of camel husbandry. The pastoralists have started negotiations with the administration to regain control of land utilization by strengthening directives for settlements, land use pattern and extraction rates. To support these initiatives the study recommends that pastoralists and other stakeholders enter into an institutionalized process of negotiation that builds on indigenous knowledge and organizational structures and facilitates validation and implementation of newly generated knowledge.

Risk Management by Communal Decision in Trans-Himalayan Farming: Manang Valley in Central Nepal

It is generally assumed that peasants optimize security of food supply rather than maximize profit. One way of securing the survival of the household is to spread risk in farming by extending the planting and harvesting seasons in order to avoid all crops being damaged if unfavorable production conditions should occur. It thus seems peculiar that some Himalayan peasant communities act in the opposite manner by compressing peak agricultural activity into a minimum period, and furthermore that all cultivators simultaneously start planting and harvesting on dates fixed by the village headman in consultation with a lama (Buddhist priest). Rather than suggesting that any single explanation for this practice is the right one, however, this article contends that specific farming system cannot be understood properly unless a combination of subsystems — or facets — are included in the analyses.

Smallholders and the ‘Household Responsibility System’: Adapting to Institutional Change in Chinese Agriculture

During the last quarter century, China’s agricultural sector has undergone a dramatic transformation from collective to private production under the so-called “Household Responsibility System.” This incentive system, designed to increase yields, reallocated communal land to peasant households, creating hundreds of millions of smallholders with relative autonomy over land use decisions and crop selection. Based on recent ethnographic research, this paper discusses the smallholder farming system of a mixed-ethnic community that intensively cultivates small land plots for subsistence and market exchange in China’s populous southwestern province of Sichuan. The paper characterizes the smallholder system in terms of biodiversity of plant and animal species, market distribution of crops, multiple cropping systems, and labor and technology inputs. The paper also describes how smallholders adapt their agricultural practices and decisions to changing market conditions and agricultural policies. Significantly, these adaptive strategies focus on shifting to the production of various cash crops, including melons and mangoes. Implications for the long-term viability of China’s smallholders, particularly in ecologically and economically marginal areas, are also discussed.

Is it a revolution?

Jablonka and Lamb's claim that evolutionary biology is undergoing a ‘revolution’ is queried. But the very concept of revolutionary change has uncertain application to a field organized in the manner of contemporary biology. The explanatory primacy of sequence properties is also discussed.

Indigenous Land Use in the Ecuadorian Amazon: A Cross-cultural and Multilevel Analysis

Among the remaining tropical forests of lowland Latin America, many are inhabited by indigenous peoples, and the sustainability of their land uses is a point of heated debate in the conservation community. Numerous small-scale studies have documented changes in indigenous land use in individual communities in the context of expanding frontier settlements and markets, but few studies have included larger populations or multiple ethnic groups. In this paper we use data from a regional-scale survey of five indigenous populations in the Northern Ecuadorian Amazon to describe their agricultural land use practices and investigate the factors that affect those practices. We find the areas cultivated by indigenous households to be small compared to those of nearby mestizo colonists, but a large proportion of indigenous cultivated area is in commercial land uses. We also construct multilevel statistical models to investigate the household and community-level factors that affect indigenous land use. The results reveal significant influences on cultivated area from contextual factors such as access to markets, oil company activities, and the land tenure regime, as well as from household characteristics such as demographic composition, participation in alternative livelihood activities, and human, social and physical capitals. Overall the results are most consistent with market integration as an underlying driver of land use change in indigenous territories of the study area.

Biological Levers and Extended Adaptationism

Two critiques of simple adaptationism are distinguished: anti-adaptationism and extended adaptationism. Adaptationists and anti-adaptationists share the presumption that an evolutionary explanation should identify the dominant simple cause of the evolutionary outcome to be explained. A consideration of extended-adaptationist models such as coevolution, niche construction and extended phenotypes reveals the inappropriateness of this presumption in explaining the evolution of certain important kinds of features—those that play particular roles in the regulation of organic processes, especially behavior. These biological or behavioral ‘levers’ are distinctively available for adaptation and exaptation by their possessors and for co-optation by other organisms. As a result they are likely to result from a distinctive and complex type of evolutionary process that conforms neither to simple adaptationist nor to anti-adaptationist styles of explanation. Many of the human features whose evolutionary explanation is most controversial belong to this category, including the female orgasm.

In Search of Sustainable Land Use and Food Security in the Arid Hillside Regions of Central America: Putting the Horse Before the Cart

This article is based on a 2003 case study of the Special Program for Food Security in two dry, upland regions of Honduras and Nicaragua. In particular the research sought to identify factors influencing farmers’ interest in various “best practices” being promoted as alternatives to the use of fire in cropping and ranching systems. The economic feasibility and/or affordability of several of these practices are questionable in light of most farmers’ priorities, risk concerns, or limited resources. The technical feasibility of several of the practices is unclear, at least in the marginal agroecological environments in which most of the farmers in these regions operate. The study highlights the weaknesses of agricultural development initiatives designed without a sufficient understanding of existing agricultural strategies and their purposes. It also reveals the limitations of technological approaches to problems of food insecurity and land degradation, and the need for broader, more integrated rural development strategies. The findings support critiques regarding the biases of many development professionals that may prevent them from giving sufficient attention to local knowledge and perspectives.

Defining vision: what homology thinking contributes

The specialization of visual function within biological function is reason for introducing “homology thinking” into explanations of the visual system. It is argued that such specialization arises when organisms evolve by differentiation from their predecessors. Thus, it is essentially historical, and visual function should be regarded as a lineage property. The colour vision of birds and mammals do not function the same way as one another, on this account, because each is an adaptation to special needs of the visual functions of predecessors—very different kinds of predecessors in each case. Thus, history underlies function. We also see how homology thinking figures in the hierarchical classification of visual systems, and how it supports the explanation of visual function by functional role analysis.

Filling the Information Void: Using Public Registries as a Tool in Nanotechnologies Regulation

Based on the experiences of two high profile voluntary data collection programs for engineered nanomaterials, this article considers the merit of an international online registry for scientific data on engineered nanomaterials and environmental, health and safety (EHS) data. Drawing on the earlier experiences from the pharmaceutical industry, the article considers whether a registry of nanomaterials at the international level is practical or indeed desirable, and if so, whether such an initiative—based on the current state of play—should be voluntary or mandatory. The article commences with an examination of the success and failures of voluntary reporting schemes in the UK and the US, as well as the International Council of Nanotechnology’s EHS Database and the OECD’s Working Party on Manufactured Nanomaterials. The article then examines the history of clinical trials registries, including the key motivations behind their creation, the role of self-regulation, and the perceived benefits thereof. Key lessons of the rise of clinical trials registration are highlighted, as are crucial considerations that must be addressed by policy makers should a multi-lateral public registry for data on nanoscale materials and EHS research be perceived to be a desirable option. The article concludes by arguing that while the creation of a registry to record information generated on nanomaterials is not straightforward, this reason alone should not deter industry from taking a proactive approach to the dissemination of fundamental data and research findings.

Adaptationism and the adaptive landscape

Debates over adaptationism can be clarified and partially resolved by careful consideration of the ‘grain’ at which evolutionary processes are described. The framework of ‘adaptive landscapes’ can be used to illustrate and facilitate this investigation. We argue that natural selection may have special status at an intermediate grain of analysis of evolutionary processes. The cases of sickle-cell disease and genomic imprinting are used as case studies.

Home Garden Production and Energetic Sustainability in Calakmul,Campeche, Mexico

Energy flows were studied for the 2002–2003 agricultural cycle in four households for which agriculture is part of a diversified survival strategy and four that practice agriculture as a business. Home garden inputs and outputs were measured monthly. Quantified inputs were: household labour, household agro-system production, and purchased external renewable and non-renewable energy. Outputs measured were: sales, family and animal foods. While both strategies had similar indicators in biomass and energy production, vegetable richness, and soil quality, household garden function and sustainability differed between subsistence and commercial householders. Subsistence gardens complemented family diet and contributed to household system resiliency. They relied heavily on renewable energy sources from within their agro-system. Gardens in commercial households reduced fruit tree area and increased animal husbandry for the market. They depended more on purchased non-renewable energy sources and were less sustainable and much less energy efficient than traditional gardens.

Asymmetries in the Friendship Preferences and Social Styles of Men and Women

Several hypotheses on the form and function of sex differences in social behaviors were tested. The results suggest that friendship preferences in both sexes can be understood in terms of perceived reciprocity potential—capacity and willingness to engage in a mutually beneficial relationship. Divergent social styles may in turn reflect trade-offs between behaviors selected to maintain large, functional coalitions in men and intimate, secure relationships in women. The findings are interpreted from a broad socio-relational framework of the types of behaviors that facilitate selective advertisement and investment of reciprocity potential across individuals and within groups of men and women.