Economic Theory Commons^™

Evidence For Height And Immune Function Trade-Offs Among Preadolescents In A High Pathogen Population, Angela R. Garcia, Aaron Blackwell, Benjamin C. Trumble, Jonathan Stieglitz, Hillard Kaplan, Michael Gurven

ESI Publications

Background

In an energy-limited environment, caloric investments in one characteristic should trade-off with investments in other characteristics. In high pathogen ecologies, biasing energy allocation towards immune function over growth would be predicted, given strong selective pressures against early-life mortality.

Methodology

In the present study, we use flow cytometry to examine trade-offs between adaptive immune function (T cell subsets, B cells), innate immune function (natural killer cells), adaptive to innate ratio and height-for-age z scores (HAZ) among young children (N = 344; aged 2 months–8 years) in the Bolivian Amazon, using maternal BMI and child weight-for-height z scores (WHZ) as …

Immune Function During Pregnancy Varies Between Ecologically Distinct Populations, Carmen Hové, Benjamin C. Trumble, Amy S. Anderson, Jonathan Stieglitz, Hillard Kaplan, Michael Gurven, Aaron Blackwell

ESI Publications

Background and objectives

Among placental mammals, females undergo immunological shifts during pregnancy to accommodate the fetus (i.e. fetal tolerance). Fetal tolerance has primarily been characterized within post-industrial populations experiencing evolutionarily novel conditions (e.g. reduced pathogen exposure), which may shape maternal response to fetal antigens. This study investigates how ecological conditions affect maternal immune status during pregnancy by comparing the direction and magnitude of immunological changes associated with each trimester among the Tsimane (a subsistence population subjected to high pathogen load) and women in the USA.

Methodology

Data from the Tsimane Health and Life History Project (N = 935) and …

Cardiovascular Disease And Type 2 Diabetes In Evolutionary Perspective: A Critical Role For Helminths?, Michael D. Gurven, Benjamin C. Trumble, Jonathan Stieglitz, Aaron D. Blackwell, David E. Michalik, Caleb E. Finch, Hillard Kaplan

ESI Publications

Heart disease and type 2 diabetes are commonly believed to be rare among contemporary subsistencelevel human populations, and by extension prehistoric populations. Although some caveats remain, evidence shows these diseases to be unusual among well-studied hunter-gatherers and other subsistence populations with minimal access to healthcare. Here we expand on a relatively new proposal for why these and other populations may not show major signs of these diseases. Chronic infections, especially helminths, may offer protection against heart disease and diabetes through direct and indirect pathways. As part of a strategy to insure their own survival and reproduction, helminths exert multiple cardio-protective …