Luseadra McKerracher

Food Aversions and Cravings during Pregnancy on Yasawa Island, Fiji

Women often experience novel food aversions and cravings during pregnancy. These appetite changes have been hypothesized to work alongside cultural strategies as adaptive responses to the challenges posed by pregnancy (e.g., maternal immune suppression). Here, we report a study that assessed whether data from an indigenous population in Fiji are consistent with the predictions of this hypothesis. We found that aversions focus predominantly on foods expected to exacerbate the challenges of pregnancy. Cravings focus on foods that provide calories and micronutrients while posing few threats to mothers and fetuses. We also found that women who experience aversions to specific foods are more likely to crave foods that meet nutritional needs similar to those provided by the aversive foods. These findings are in line with the predictions of the hypothesis. This adds further weight to the argument that appetite changes may function in parallel with cultural mechanisms to solve pregnancy challenges.

Biocultural theory: The current state of knowledge.

Biocultural theory is an integrative research program designed to investigate the causal interactions between biological adaptations and cultural constructions. From the biocultural perspective, cultural processes are rooted in the biological necessities of the human life cycle: specifically human forms of birth, growth, survival, mating, parenting, and sociality. Conversely, from the biocultural perspective, human biological processes are constrained, organized, and developed by culture, which includes technology, culturally specific socioeconomic and political structures, religious and ideological beliefs, and artistic practices such as music, dance, painting, and storytelling. Establishing biocultural theory as a program that self-consciously encompasses the different particular forms of human evolutionary research could help scholars and scientists envision their own specialized areas of research as contributions to a coherent, collective research program. This article argues that a mature biocultural paradigm needs to be informed by at least 7 major research clusters: (a) gene-culture coevolution; (b) human life history theory; (c) evolutionary social psychology; (d) anthropological research on contemporary hunter-gatherers; (e) biocultural socioeconomic and political history; (f) evolutionary aesthetics; and (g) biocultural research in the humanities (religions, ideologies, the history of ideas, and the arts). This article explains the way these research clusters are integrated in biocultural theory, evaluates the level of development in each cluster, and locates current biocultural theory within the historical trajectory of the social sciences and the humanities.

The ex-pat effect: presence of recent Western immigrants is associated with changes in age at first birth and birth rate in a Maya population from rural Guatemala

Abstract Background: Economic transitions expose indigenous populations to a variety of ecological and cultural challenges, especially regarding diet and stress. These kinds of challenges are predicted by evolutionary ecological theory to have fitness consequences (differential reproduction) and, indeed, are often associated with changes in fertility dynamics. It is currently unclear whether international immigration might impact the nature of such an economic transition or its consequences for fertility. Aim: To examine measures of fertility, diet and stress in two economically transitioning Maya villages in Guatemala that have been differentially exposed to immigration by Westerners. Subjects and methods: This study compared Maya women’s ages at first birth and birth rates between villages and investigated whether these fertility indicators changed through time. It also explored whether the villages differed in relation to diet and/or a proxy of stress. Results: It was found that, in the village directly impacted by immigration, first births occurred earlier, but birth rate was slower. In both villages, over the sampled time window, age at first birth increased, while birth rate decreased. The villages do not differ significantly in dietary indicators, but the immigration-affected village scored higher on the stress proxy. Conclusion: Immigration can affect fertility in host communities. This relationship between immigration and fertility dynamics may be partly attributable to stress, but this possibility should be evaluated prospectively in future research.

Breastfeeding and infant growth

Globally, mothers from a wide variety of socio-environmental contexts often assume slow-growing babies are underfed and erroneously attribute perceived growth retardation to inadequate milk supply or poor milk quality [1]. These assumptions frequently prompt replacement of breastmilk with formula or other nonbreastmilk foods to encourage infant weight and length gains [1]. This tendency to truncate breastfeeding to accelerate growth is exacerbated by some features of contemporary environments in both developing and developed nations such as growing rates of maternal obesity and caesarean section that interfere with breastfeeding. Unfortunately, regardless of the primary reason for truncation, cessation of exclusive breastfeeding before 4–6 months and of continued breastfeeding before 12 months is associated with increased risk of gastrointestinal infections and poor immune system development in infancy, and obesity and a variety of non-communicable diseases in later life [2]. Although stunting and wasting in children do represent major public health challenges in lowand middle-income countries, these phenomena should not be confused with unfaltering growth less than two standard deviations below global averages. EVOLUTIONARY PERSPECTIVES