Reproductive inequality in humans and other mammals.

To address claims of human exceptionalism, we determine where humans fit within the greater mammalian distribution of reproductive inequality. We show that humans exhibit lower reproductive skew (i.e., inequality in the number of surviving offspring) among males and smaller sex differences in reproductive skew than most other mammals, while nevertheless falling within the mammalian range. Additionally, female reproductive skew is higher in polygynous human populations than in polygynous nonhumans mammals on average. This patterning of skew can be attributed in part to the prevalence of monogamy in humans compared to the predominance of polygyny in nonhuman mammals, to the limited degree of polygyny in the human societies that practice it, and to the importance of unequally held rival resources to women's fitness. The muted reproductive inequality observed in humans appears to be linked to several unusual characteristics of our species-including high levels of cooperation among males, high dependence on unequally held rival resources, complementarities between maternal and paternal investment, as well as social and legal institutions that enforce monogamous norms.

Measuring food insecurity: An introduction to tools for human biologists and ecologists.

OBJECTIVE: Food insecurity is a significant and growing concern undermining the wellbeing of 30% of the global population. Food in/security is a complex construct consisting of four dimensions: availability, access, utilization, and stability, making it challenging to measure. We provide a toolkit human biologists/ecologists can use to advance research on this topic. METHODS: We review the strengths and limitations of common tools used to measure food access and utilization, the two dimensions most proximate to people's lived experience, and emphasize tools that provide data needed to best link food security with human biological outcomes. We also discuss methods that provide contextual data human biologists/ecologists will find useful for study design, ensuring instrument validity, and improving data quality. RESULTS: Food access is principally measured using experience-based instruments that emphasize economic access. Social access, such as food sharing, is under-studied and we recommend using social network analysis to explore this dimension. In terms of utilization, emphasis has been on food choice measured as dietary diversity. Food preparation and intrahousehold distribution, also part of the utilization dimension, are less studied and standardized instruments for measuring both are lacking. The embodiment of food insecurity has focused on child growth, although a growing literature addresses adult mental wellbeing and chronic and infectious disease risk. CONCLUSIONS: We see the potential to expand outcomes to include reproductive and immune function, physical activity, and the gut microbiome. Human biologists/ecologists are well-positioned to advance understanding of the human health impacts of food insecurity and provide data to support intervention efforts.

Linking subsistence harvest diversity and productivity to adaptive capacity in an Alaskan food sharing network.

BACKGROUND: Although anthropogenic climate change poses existential challenges for Indigenous communities in the Arctic, these challenges are not entirely unprecedented. Over many generations, Arctic peoples have developed a wide range of behavioral strategies to navigate environmental change and uncertainty, and these strategies provide a foundation for contemporary adaptation. AIMS: In this article, we focus on mixed cash-subsistence economies and the social networks that underlie them in Alaska. The patterns of food production, labor exchange, and food sharing in subsistence-oriented communities throughout Alaska are driven by the productivity of keystone households who regularly harvest and share resources within and between communities. MATERIALS & METHODS: Building on previous research suggesting the critical importance of these networks to community resilience, we use network analysis to investigate whether patterns in resource transfers between households are associated with subsistence harvest diversity-the diversity of species harvested by a household unit. We use exponential random graph models to describe the structure of a sharing network from Aniak, Alaska, and model the links between harvest productivity, harvest diversity, and household position in this network. RESULTS: Our results indicate that both productivity and diversity are positively associated with network connections, and that productivity alone provides an incomplete model of network structure. DISCUSSION: We suggest that subsistence harvest diversity may play a unique role in supporting adaptive capacity and resilience by maintaining the productivity of keystone households despite changing environments and sustaining social network structures that circulate resources throughout the community. Harvest diversity may also serve as a broad indicator of Indigenous ecological knowledge and a tangible representation of cultural practices, values, and worldviews that underlie subsistence in Alaska. CONCLUSION: Greater attention to harvest diversity is important for understanding how subsistence networks adapt to environmental change and uncertainty linked to social and ecological dynamics of anthropogenic climate change.