Life Sciences Commons^™

Natural Selection Of Immune And Metabolic Genes Associated With Health In Two Lowland Bolivian Populations, Amanda J. Lea, Angela Garcia, Jesusa Arevalo, Julien F. Ayroles, Kenneth Buetow, Steve W. Cole, Daniel Eid Rodriguez, Maguin Gutierrez, Heather M. Highland, Paul L. Hooper, Anne Justice, Thomas Kraft, Kari E. North, Jonathan Stieglitz, Hillard Kaplan, Benjamin C. Trumble, Michael Gurven

ESI Publications

A growing body of work has addressed human adaptations to diverse environments using genomic data, but few studies have connected putatively selected alleles to phenotypes, much less among underrepresented populations such as Amerindians. Studies of natural selection and genotype–phenotype relationships in underrepresented populations hold potential to uncover previously undescribed loci underlying evolutionarily and biomedically relevant traits. Here, we worked with the Tsimane and the Moseten, two Amerindian populations inhabiting the Bolivian lowlands. We focused most intensively on the Tsimane, because long-term anthropological work with this group has shown that they have a high burden of both macro and microparasites, as …

Anything For A Cheerio: Brown Capuchins (Sapajus [Cebus] Apella) Consistently Coordinate In An Assurance Game For Unequal Payoffs, Lauren M. Robinson, Mayte Martínez, Kelly L. Leverett, Mattea S. Rossettie, Bart J. Wilson, Sarah F. Brosnan

ESI Publications

Unequal outcomes disrupt cooperation in some situations, but this has not been tested in the context of coordination in economic games. To explore this, we tested brown capuchins (Sapajus [Cebus] apella) on a manual version of the Stag Hunt (or Assurance) Game, in which individuals sequentially chose between two options, Stag or Hare, and were rewarded according to their choices and that of their partner. Typically, coordination on Stag results in an equal highest payout, whereas coordinating on Hare results in a guaranteed equal but lower payoff and uncoordinated play results in the lowest payoff when playing …

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 …

Predictable And Predictive Emotions: Explaining Cheap Signals And Trust Re-Extension, Eric Schniter, Roman M. Sheremeta

ESI Publications

Despite normative predictions from economics and biology, unrelated strangers will often develop the trust necessary to reap gains from one-shot economic exchange opportunities. This appears to be especially true when declared intentions and emotions can be cheaply communicated. Perhaps even more puzzling to economists and biologists is the observation that anonymous and unrelated individuals, known to have breached trust, often make effective use of cheap signals, such as promises and apologies, to encourage trust re-extension. We used a pair of trust games with one-way communication and an emotion survey to investigate the role of emotions in regulating the propensity to …

Responses To The Assurance Game In Monkeys, Apes, And Humans Using Equivalent Procedures, Sarah F. Brosnan, Audrey E. Parrish, Michael J. Beran, Timothy Flemming, Lisa Heimbauer, Catherine F. Talbot, Susan P. Lambeth, Steven J. Schapiro, Bart J. Wilson

ESI Publications

There is great interest in the evolution of economic behavior. In typical studies, species are asked to play one of a series of economic games, derived from game theory, and their responses are compared. The advantage of this approach is the relative level of consistency and control that emerges from the games themselves; however, in the typical experiment, procedures and conditions differ widely, particularly between humans and other species. Thus, in the current study, we investigated how three primate species, capuchin monkeys, chimpanzees, and humans, played the Assurance (or Stag Hunt) game using procedures that were, to the best of …

A Neuroeconomic Theory Of The Decision Process, John Dickhaut, Aldo Rustichini, Vernon L. Smith

ESI Publications

We develop a neuronal theory of the choice process (NTCP), which takes a subject from the moment in which two options are presented to the selection of one of the two. The theory is based on an optimal signal detection, which generalizes the signal detection theory by adding the choice of effort as optimal choice for a given informational value of the signal for every effort level and a cost of effort. NTCP predicts the choice made as a stochastic choice: That is, as a probability distribution over two options in a set, the level of effort provided, the error …