Center for Behavior, Evolution, and Culture

Hillard Kaplan - An evolutionary-physiological model of human energy management and the emergence of novel non-communicable diseases
2025-03-31 12:00 - 13:30 (America/Los_Angeles) | 352 Haines Hall
An evolutionary-physiological model of human energy management and the emergence of novel non-communicable diseases
Hillard Kaplan
Professor, Anthropology, University of New Mexico
Research Affiliate, Economic Science Institute, Chapman University
This talk presents recent findings obtained with Tsimane and Moseten Native South Americans showing that they 1) engage in high levels of physical activity, and have a high burden of infectious disease and high fertility rates; 2) have a very low prevalence of heart disease and dementia; 3) have slower rates of brain volume loss with age than U.S. and European populations; and 4) evidence a curvilinear relationship of BMI and non-HDL cholesterol with brain volume. Based on those results, I propose a theoretical model of the evolved human energy management system, focusing on the regulation and use of macronutrients in supporting physical activity, brain function, immunity, and reproduction. This is followed by a quantitative model that examines how natural selection would act on exogenous changes in energy supply and expenditure. The final part of the talk utilizes the model to explore how recent rapid changes in energy supply, physical activity, pathogen burden and reproduction result in increased risk of diabetes, heart disease, dementia, and cancer.

Ny Vasil - Generic generalizations within and across contexts
2025-04-14 12:00 - 13:30
Generic generalizations within and across contexts
Ny Vasil
Assistant Professor
Psychology Department, California State University East Bay
Generic generalizations about natural and social kinds (e.g., “Raccoons have rabies”; “Trader Joe’s cashiers are friendly”) shape how agents learn, explain and intervene on their environment. Yet, there’s no consensus about what underwrites people’s endorsement of generic generalizations. This talk brings together ideas from psychology, philosophy and linguistics to argue that stability of the described relationship – the extent to which it holds across various contexts, real or hypothetical – plays an important role in people’s endorsement of generic generalizations about natural and social kinds, and about causal relationships in these domains. In a series of empirical studies, we explore how agents navigate the world composed of both broad and narrow patterns, how the search for robust non-accidental regularities is flexibly adapted to handle “sociocultural bubbles” and other exceptions to universality, and how this capacity develops. In conclusion, I will discuss how the proposed account coheres with the psychological functions of generalizations.

Katrine Whiteson - May the Fiber Be with You: Gut Microbiomes from a remote Amazon village to the undergraduate lab
2025-04-28 12:00 - 13:30
May the Fiber Be with You: Gut Microbiomes from a remote Amazon village to the undergraduate lab
Katrine Whiteson
University of California Irvine School of Biological Sciences, co-Director, UCI Microbiome Center
Bacterial and viral colonization of the human body has profound implications for human health, yet our understanding of what constitutes a “healthy microbiome” remains incomplete—especially in the context of industrialization. Over the past century, global diets have shifted dramatically, with increased consumption of processed foods and a steep decline in dietary fiber intake. These changes have left our colons depleted of critical substrates that fuel gut microbial communities, with potential consequences for immune function, metabolic health, and chronic disease risk.
To explore what a less industrialized microbiome might look like, we studied the gut, oral, and fermented food microbiomes of women and children from 28 households in Conambo, a remote Indigenous community along the Conambo River in the Ecuadorian Amazon. This community is largely isolated from urban infrastructure, with minimal exposure to processed foods or modern medical care. Microbiome profiles from Conambo participants revealed high diversity and a dominance of microbial taxa such as Prevotellaceae.
We also analyzed chicha, a traditional fermented manioc beverage prepared by mastication of boiled cassava tubers. Our findings revealed microbial succession during fermentation and close taxonomic overlaps with oral and gut microbiota—underscoring the intimate links between diet, tradition, and microbial transmission. Within Conambo, household co-residence emerged as a strong driver of microbiome similarity across fecal, saliva, and chicha samples.
Finally, we contextualized the Conambo microbiomes by comparing them to global reference datasets, including UC Irvine undergraduates participating in dietary fiber intervention studies. Together, these datasets reveal how environmental exposure, diet, and social structure shape the human microbiome—and offer a lens into both human microbial history and the future of microbiome-informed health.

Annie E. Wertz - How infants learn to eat plants (and why they may not want to)
2025-05-12 12:00 - 13:30
How infants learn to eat plants (and why they may not want to)
Annie E. Wertz
Assistant Professor, Psychological & Brain Sciences
University of California, Santa Barbara
Life is mostly plants. Plants constitute an estimated 80% of the biomass on Earth and are concentrated in terrestrial environments. Millions of animal species rely on plants to survive and the organismic design of plants and animals have been tightly interwoven in intricate ways over evolutionary time. Humans are no exception. Plants have been a foundational component of human diets across evolutionary time, yet many plants can be toxic or even fatal if ingested. In this talk, I will present research exploring the cognitive adaptations human infants use to negotiate this paradox and safely learn which plants they can eat.

Erin Riley - Roadside primates: Balancing risks and rewards in anthropogenic environments
2025-06-02 12:00 - 13:30
Roadside primates: Balancing risks and rewards in anthropogenic environments
Erin Riley
Professor, Anthropology, San Diego State University
In the contemporary era it is becoming increasingly difficult to find a primate population that has not experienced some form of anthropogenic influence. Primates living in anthropogenic spaces may benefit from access to novel food resources, such as agricultural crops or provisioned foods, but they also must deal with potential negative outcomes from the presence of humans and their activities. The complexity of these human-primate interfaces necessitates the use of interdisciplinary approaches that draw from both the natural and social sciences. In this talk, I will discuss my research on the human-macaque interface in Sulawesi, Indonesia, highlighting the mixed methods approaches my colleagues and I are using to examine how macaques and people are co-adapting to ever-expanding shared landscapes.
