Center for Behavior, Evolution, and Culture

Stacy Rosenbaum (Univ. Michigan) - "The long arm of “childhood:” what can other primates teach us about the early life origins of aging and resiliency?"
2025-10-20 12:00 - 13:30 (America/Los_Angeles) | 352 Haines Hall
Early life experiences are widely thought to shape adult behavior, health, and fitness across the tree of life. The deep evolutionary roots of these “early life effects”—seen in organisms ranging from plants to primates—have sparked considerable interest in their biological underpinnings. While individual variation in responses to early life adversity is well recognized, new research suggests that species-level differences may also be considerable. In this talk, I present longitudinal data from wild savannah baboons and mountain gorillas showing that similar forms of early life adversity can have dramatically different outcomes depending on the species. I explore the socioecological factors that may drive this variation and discuss how these insights can inform our broader understanding of aging and resilience in primates, including humans.

Change of plans: Our speaker will not be able to attend in person and will give her talk via Zoom.
Enrolled students are still expected to attend in person to watch the zoom presentation together (in 352 Haines Hall). We will still have individual meetings between the speaker and students.
https://ucla.zoom.us/j/94308730584?pwd=[REDACTED]
Meeting ID: 943 0873 0584
Passcode: [REDACTED]

Richard Karban (UC-Davis) - Plant Communication and Individual Personalities
2025-11-03 12:00 - 13:30
This talk will attempt to answer three questions: 1) Do plants communicate about their risk of herbivory? 2) Do plants have individual personalities with respect to communication? 3) Why does this matter?
Biologists have known for a long time that plants sense their environments and respond accordingly, i.e., they exhibit “behavior.” Whether they communicate with each other with respect to their risk of being attacked by insect herbivores has been more controversial. We have found that sagebrush plants that are attacked by insects or mechanically damaged emit volatiles. Neighboring sagebrush plants sense these volatiles and increase their resistance to herbivory. Volatiles are required for this eavesdropping between individuals and between branches on a single individual. In the field, this eavesdropping increased the survival of seedlings and the production of flowers and new shoots for older plants. Individual plants showed relatively stable tendencies in their emission of active cues and also in their responses to cues. In other words, they showed tendencies that were consistent over time and also consistent across different situations, i.e., they exhibited personalities. For example, individuals that were good receivers were also good emitters. Recognizing that plants communicate via volatile cues expands our view of the sophisticated behaviors that plants are capable of. It may also allow us to design more effective pest management strategies. Recognizing that plants have individual personalities forces us to think about their past experiences and to consider correlations between behaviors.

Zoom link for those unable to attend in person:
https://ucla.zoom.us/j/94308730584?pwd=[REDACTED]
Meeting ID: 943 0873 0584
Passcode: [REDACTED]

Bret Beheim, MPI-EVAN - "Planck's Principle, Price's Theorem and the Forces of Cultural Evolution" (via Zoom)
2025-11-17 12:00 - 13:30
Abstract:
Physicist Max Planck famously said that “A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die”. This is basically a theory of human cultural change, one rooted primarily in the mechanisms of differential recruitment, inheritance and demography. If the Planck Principle (as it has come to be known) is a key explanatory force, it has major implications for the study of cultural evolution, which has instead traditionally focused on the role of social and individual learning (as people ‘see the light’). Although there have been several projects focusing on the role of demographic turnover in cultural evolution, evidence to date has been mixed and equivocal. A key theoretical limitation has been the lack of a principled way to compare the relative strength of different forces of cultural evolution.
To solve this problem, we adapt the method of *evolutionary decomposition* pioneered in mathematical demography, which applies Price’s Theorem to trajectories of phenotypic change. Using a novel derivation of this approach tailored to historical archives of creative human culture, we can measure (for the first time) the relatively explanatory strength of three categories of force in cultural evolution, namely, the entrances of new cohorts, the process of attrition, and the “changiness” of individuals over the course of their creative careers. Taking this to a variety of high-resolution longitudinal datasets, including song lyrics, board game strategies, and stylistic themes in European literature and musical compositions, we find strong evidence for the importance of population turnover and the entrance of new cohorts with splashy, disruptive ideas. Rather than Planck’s formulation of cultural change “one funeral at a time”, however, we find instead many circumstances where cultural change occurs “one birth at a time”. We also find systematic differences in the relative strength of these three categories of force, with some systems being driven by social learning and strategic adoption dynamics consistent with the canonical models of social learning, while others being mostly characterized by the slower process of demographic replacement. Our results demonstrate the value of an expanded, force-centric approach to studying long-term cultural change.
Zoom link:
https://ucla.zoom.us/j/94308730584?pwd=[REDACTED]
Meeting ID: 943 0873 0584
Passcode: [REDACTED]

Katie Sayre, UCSB - Title: "Loneliness and health: insights from the Tsimane Health and Life History Project"
2025-12-01 12:00 - 13:30
Abstract: Loneliness as a public health concern has exploded in recent years. Recognition of its widespread prevalence and presumed recency have led to declarations that a “loneliness epidemic” faces industrialized populations. Changes to certain aspects of modern life—fewer face-to-face interactions, more time spent alone, more people living by themselves—are thought to exacerbate loneliness, and imply that it may be a relatively recent phenomenon, tied to capitalism and the market economy. Recent meta-analyses, however, suggest that adults in lower- and middle-income countries also experience loneliness, despite living in socially embedded contexts. Still, most research on loneliness and its behavioral and health correlates focuses primarily on those people living in higher-income countries. In this talk, I will discuss recent work examining loneliness, the social environment, and health in Tsimane and Moseten forager-horticulturalists of Bolivia. This work challenges the concept that loneliness necessarily results from processes of the market economy, and suggests that loneliness is not confined to industrialized settings but likely represents a shared aspect of human experience.
Zoom link for those unable to attend in person:
https://ucla.zoom.us/j/94308730584?pwd=[REDACTED]
Meeting ID: 943 0873 0584
Passcode: [REDACTED]

Delaney Knorr, Duke University -- Title: Evolutionary Constraints on Human Pregnancy: How Social Environments and Energetic Limits Shape Maternal-Fetal Health
2026-01-05 12:00 - 13:30
Abstract: Human pregnancy is an energetically demanding and socially embedded process that requires mothers to balance competing physiological needs while maintaining fetal development. In this talk, I integrate biocultural and mechanistic approaches to examine how social, ecological, and energetic environments become biologically embedded during gestation. Drawing on mixed-methods research with Latina women in the U.S., I show how neighborhood context, discrimination, and sociopolitical stress shape maternal psychological distress, and how support from allomothers buffers these effects. I then present evidence from immunological and placental biology indicating that maternal stress is linked to reductions in regulatory T cells and placental extracellular vesicles, revealing potential pathways through which social experience influences maternal-fetal communication and immune tolerance. Finally, I discuss findings from a project measuring total energy expenditure in pregnancy using doubly labeled water to test whether physical activity and psychosocial stress push gestation toward a metabolic ceiling. Together, this work highlights how social environments and energetic constraints jointly structure maternal-fetal trade-offs.

Katie Starkweather, UCSB
2026-01-26 12:00 - 13:30

Amy Non, Dept of Anthropology, UCSD
2026-02-09 12:00 - 13:30

Greg Grether, EEB, UCLA
2026-02-23 12:00 - 13:30

Sara Lowes, Economics, UCSD
2026-03-09 12:00 - 13:30

Joan Silk, School of Human Evolution and Social Change, ASU
2026-03-30 12:00 - 13:30

Eva Jablonka, Prof. Emeritus, Tel Aviv Univ.
2026-04-13 12:00 - 13:30

Frank Marlowe Memorial Lecturer: Mike Gurven, Anthropology, UCSB
2026-04-20 12:00 - 13:30

Kim Zhu
2026-05-04 12:00 - 13:30

Morgan Tingley, EEB, UCLA: "To move, or not to move? How species respond to a warming climate"
2026-05-18 12:00 - 13:30

Ashley Mensing, Dept of Anthropology, UCLA
2026-06-01 12:00 - 13:30
