Paul W. Leslie

Effect on infant mortality of iodination of irrigation water in a severely iodine-deficient area of China

BACKGROUND Hotien county in Xinjiang province, China, is an area of severe iodine deficiency and has a high infantmortality rate. We investigated whether iodine replacement through iodination of the irrigation water would decrease infant mortality. METHODS We added potassium iodate to irrigation water over a 2 to 4 week period beginning in 1992 in certain areas of three townships (Tusala, Long Ru, and Bakechi). Logistic regression analysis was used to compare the odds ratios for infant and neonatal mortality in treated and intreated areas. FINDINGS The median urinary iodine concentration significantly increased in women of child-bearing age from < 10 micrograms/L to 55 micrograms/L. Infant-mortality rates decreased in the treated areas of Long Ru (mean [SD] 58.2 [4.4] per 1000 births to 28.7 [7.1] per 1000 births), Tusala (47.4 [12.4] per 1000 births to 19.1 [1.5] per 1000 births), and Bakechi (106.2 [9.5] per 1000 births to 57.3 [7.3] per 1000 births). Similar results were also seen for neonatal mortality. On regression analysis iodine treatment and time were significant independent predictors of infant mortality. INTERPRETATION Iodine supplementation of irrigation water in areas of severe iodine deficiency decreases neonatal and infant mortality. Iodine replacement has probably been an important factor in the national decrease in infant mortality in China.

Cattle Raiding, Cultural Survival, and Adaptability of East African Pastoralists

Since the late 1970s, cattle raiding with automatic weapons has escalated among nomadic herding societies in northern East Africa. We examine the impact of AK47 raiding on the adaptability of Karimojong agropastoralists in northern Uganda. Most notably, raiding is linked to a loss of population resilience in Karamoja, measured in increased mortality of young children and of adult males in their prime reproductive years and decreased female fertility. AK47 raiding has acted both directly and indirectly as a Darwinian stressor in this population, compromising longstanding adaptive strategies and intensifying selection pressure. We briefly discuss similar effects of recently altered patterns of raiding among related Turkana pastoralists in Kenya. We then consider the process by which this traditional cultural institution was modified in the interests of preserving cultural identity. We conclude nonetheless that cattle raiding with automatic weapons constitutes singularly maladaptive cultural behavior in contemporary pastoralist societies. Indeed, it represents the single greatest threat to their biobehavioral resilience and ultimately may have profound evolutionary costs in terms of pastoralists survival.

Response Diversity and Resilience in Social-Ecological Systems

Recent work in ecology suggests that the diversity of responses to environmental change among species contributing to the same ecosystem function can strongly influence ecosystem resilience. To render this important realization more useful for understanding coupled human-natural systems, we broaden the concept of response diversity to include heterogeneity in human decisions and action. Simply put, not all actors respond the same way to challenges, opportunities, and risks. The range, prevalence, and spatial and temporal distributions of different responses may be crucial to the resilience or the transformation of a social-ecological system and thus have a bearing on human vulnerability and well-being in the face of environmental, socioeconomic, and political change. Response diversity can be seen at multiple scales (e.g., household, village, region), and response diversity at one scale may act synergistically with or contrary to the effects of diversity at another scale. Although considerable research on the sources of response diversity has been done, our argument is that the consequences of response diversity warrant closer attention. We illustrate this argument with examples drawn from our studies of two East African pastoral populations and discuss the relationship of response diversity to characteristics of social-ecological systems that can promote or diminish resilience.

Risk-sensitive fertility: The variance compensation hypothesis

Two conditions are sufficient to indicate the need for risk-sensitive, adaptive analysis: (i) the outcomes of a behavior must be unpredictable to some degree and (ii) the relationship between outcomes and their value (in terms of fitness or utility) must be nonlinear. We argue that these conditions are common, and develop a general model for the analysis of risk-sensitive fertility behavior when long-term reproductive outcomes are unpredictable. We show that unpredictability is likely to have a patterned effect on fertility behavior, beyond adjustment for expected or average mortality, and we analyze the conditions under which that effect will be to promote or dampen fertility (positive or negative variance compensation, respectively). We then describe the implications of this variance compensation hypothesis (VCH) for the analysis of demographic transitions, agricultural intensification, fertility differences in natural-fertility populations, and clutch size. We conclude by lamenting that data are lacking to test the VCH, probably because it has not been appreciated that there can be patterned and effective behavioral adjustments to stochastic features of the environment. D 2002 Elsevier Science Inc. All rights reserved.

Caloric requirements of human populations: A model

Currently available models used for predicting human caloric requirements do not reflect the great variability in activity patterns observed among populations, and are insensitive to important anthropometric, demographic, and environmental variables. They are thus inadequate for application to many populations and problems of anthropological interest. We present a model for determining caloric requirements which more accurately accommodates the effects of variation in activity and in anthropometries on individual needs, and which predicts population requirements based on individual needs and demographic parameters. The model is tested on four populations (the Andean community of Nuñoa, Peru, the Dobe !Kung of Botswana, and two New Guinean villages) and is found to provide consistently better estimates of caloric requirements than are generated by the Food and Agriculture/World Health Organizations model. This model should be useful to anthropologists and human ecologists concerned with problems involving human energy consumption, such as the efficiency of subsistence strategies, optimum family composition, or certain consequences of increased labor migration or technological change.

Energy reserves and parity of nomadic and settled Turkana women

Members of the Turkana tribe include settled and nomadic peoples who reside in the southern part of Turkana District in the semiarid region of northwest Kenya. Nomadic Ngisonyoka Turkana keep livestock (camels, cattle, sheep, goats, donkeys), subsist principally on livestock products, and move camps frequently in search of forage for the livestock; settled Turkana cultivate foods along the principal rivers. Both nomadic and settled Turkana are subject to limited food resources on seasonal and long‐term bases. Protein from meat, blood, and milk is sufficient in the diet, but food energy is limited, as are body fat reserves. Previous work has documented a decline in maternal adiposity with age in a large sample of the relatively lean nomadic women, and a negative association of fat stores with parity in a smaller sample of nomadic women. The problem of maternal depletion of fat energy reserves as a function of female reproductive history is explored in this study through anthropometry in a relatively large sample (N = 312) of nomadic and settled women. Both nomadic and settled women displayed some parity‐related losses in fat stores. The relationship was stronger in the nomads, even after controlling for age.

Feedbacks between Conservation and Social‐Ecological Systems

Robust ways to meet objectives of environmental conservation and social and economic development remain elusive. This struggle may in part be related to insufficient understanding of the feedbacks between conservation initiatives and social-ecological systems, specifically, the ways in which conservation initiatives result in social changes that have secondary effects on the environments targeted by conservation. To explore this idea, we sampled peer-reviewed articles addressing the social and environmental dimensions of conservation and coded each paper according to its research focus and characterization of these feedbacks. The majority of articles in our sample focused either on the effect of conservation initiatives on people (e.g., relocation, employment) or the effect of people on the environment (e.g., fragmentation, conservation efficacy of traditional management systems). Few studies in our sample empirically addressed both the social dynamics resulting from conservation initiatives and subsequent environmental effects. In many cases, one was measured and the other was discussed anecdotally. Among the studies that describe feedbacks between social and environmental variables, there was more evidence of positive (amplifying) feedbacks between social and environmental outcomes (i.e., undesirable social outcomes yielded undesirable environmental effects and desirable social outcomes yielded desirable environmental effects). The major themes within the sampled literature include conflict between humans and wild animals, social movements, adaptive comanagement, loss of traditional management systems, traditional ecological knowledge, human displacement and risks to livelihoods, and conservation and development. The narratives associated with each theme can serve as hypotheses for facilitating further discussion about conservation issues and for catalyzing future studies of the feedbacks between conservation and social-ecological systems.

Partitioning chi-square for the analysis of frequency table data: an archaeological application

Abstract Archaeologists often wish to compare observed frequency distributions with expectations generated by a model. We describe a technique of partitioning chisquare which yields information about goodness of fit to a model and about homogeneity among populations simultaneously, and which is often superior to other commonly used methods of evaluating frequency data. The technique is demonstrated with data from the Upper Paleolithic rockshelter Le Flageolet I. The results suggest selective raw material use by the Aurignacian occupants.

Collecting women's reproductive histories

The importance of womens reproductive histories for scientific questions mandates rigor in collecting data. Unfortunately, few studies say much about how histories were constructed and validated. The aim of this report, therefore, is to illustrate the elements of a rigorous system of data collection. It focuses particularly on potential sources of inaccuracy in collecting reproductive histories and on options for avoiding them and evaluating the results. A few studies are exemplary in their description of methods of data collection and evaluation of data quality because they clearly address the main issues of ascertaining whether or not an event occurred and, if so, its timing. Fundamental variables such as chronological age, live birth, or marriage may have different meanings in different cultures or communities. Techniques start with asking the appropriate people meaningful questions that they can and will answer, in suitable settings, about themselves and others. Good community relations and well‐trained, aware interviewers who check and cross‐check, are fundamental. A range of techniques estimate age, date events, and optimize the value of imperfect data. Robust data collection procedures rely on skillful and knowledgeable interviewing. Reliability can be improved, evaluated and explained. Researchers can plan to implement robust data collection procedures and should assess their data for the scientific community to raise confidence in reproductive history data. Am. J. Hum. Biol. 26:577–589, 2014.

Differences in intergenerational fertility associations by sex and race in Saba, Dutch Caribbean, 1876–2004

This study examines the intergenerational transmission of fertility behavior in Saba, Dutch Caribbean from 1876 to 2004 using reconstituted genealogies. Pearson product-moment correlation coefficients of several fertility measures and event-history models of age at first birth are used to explore relationships between the fertility of mothers and their children. The strength of intergenerational fertility ties varies by race and gender. Individuals that are better positioned to realize their fertility preferences have the strongest intergenerational associations, while individuals with the most limited reproductive options have the weakest intergenerational associations. This evidence supports hypotheses that posit the intergenerational transmission of attitudes, goals, and behaviors and the ability to act on those preferences as drivers of the presence or magnitude of links between the fertility of parents and their children.