Sarah Kocher

Principal Investigator

Sarah is an evolutionary biologist and geneticist interested in how social behaviors arise and evolve. Her lab studies socially variable bees to understand the factors that shape the evolution of social behavior. Her lab integrates methods from many different areas of biology, from evolutionary and population genomics to neurobiology and field ecology. Kocher is an HHMI Freeman Hrabowski Scholar and an Associate Professor in the department of Integrative Biology at UC Berkeley.

Eli Wyman

Lab Manager

Eli began his foray into the biological sciences as a volunteer at the Belize Botanic Gardens, where he got his very first taste of neotropical biodiversity. Later, he found himself a bit adrift in Costa Rica for “one year”, and he decided to volunteer at a butterfly garden and insect museum. It was here that Eli was first exposed to the science of entomology and he knew right away this would become a major interest in his life. At this time, he was most fascinated by the odd and highly variable pronotums of tropical Membracidae as well as their maternal care behaviors. Eli was quickly offered a managerial position at the gardens, where he stayed for four years, but eventually felt homesick and made his way back to the USA. Keen to continue working with insects, Eli almost magically landed a position at the American Museum of Natural History working with Jerome “Jerry” Rozen and John Ascher, where he remained for four years. Drs. Rozen and Ascher became mentors and inspirations to Eli, and their knowledge and affection for bees became integral to his scientific interests. During that time he learned a great deal about bees and met many researchers working on Hymenoptera, including Dr. Kocher. Seeing a very rare opportunity to work with both membracids and bees while expanding his knowledge of genomics, Eli jumped at the chance to join the Kocher Lab.

Andrew Webb

Research Specialist

Andrew studied Biotechnology (B.Sc. cum laude) and Genetics (M.Sc.) at UC Davis where his research examined developmental mutations in chickens with Dr. Mary Delany. He joined Dr. Mary O’Connel’s lab for his doctoral studies, where he studied the molecular underpinnings of phenotypic variation in humans and mice. He then joined Jody Hey’s lab at Temple where he developed bioinformatic pipelines to faciltate consistent, standardized population genetic pipelines.

Atul Pandey

Research Specialist

Atul studies the mechanisms of social behavior in bumble bees, working in the Kocher Lab at UC Berkeley. His research centers on how early-life social experience and diverse social signals shape the formation and dynamics of dominance hierarchies in bumble bees, particularly how social cues/interactions during a bee’s earliest stages influence its later social rank, behavior, and reproductive potential within the colony.

Alongside, he is developing genetic manipulation tools for bumble bees, expanding the molecular toolkit available for this system and enabling more precise, mechanistic tests of how genes and early experience jointly shape social outcomes. By combining behavioral experiments with new genetic approaches, his work aims to bridge the gap between proximate developmental mechanisms and the broader evolutionary forces that give rise to social behavioral complexity in insects.

Scott Wolf

Scientist/Barista

Anne Larsen

Staff Research Associate

Anne is broadly interested in understanding social evolution in socially flexible species and the interplay of environment and social phenotype. She completed her undergraduate degree in Ecology and Evolutionary Biology at Princeton University and currently works as a Staff Research Associate in the Kocher Lab at UC Berkeley, where she helps manage the lab, conducts fieldwork in the US and Japan, and takes care of bee colonies in the lab.

Callum Kingwell

Postdoc

Callum is interested in mechanisms of communication and their evolution, and in particular chemical signaling systems which are used extensively by social insects. He completed a B.Sc. (hons.) in Evolutionary Biology at the University of British Columbia, then completed his Ph.D. in Dr. Robert Raguso’s lab in the Department of Neurobiology and Behavior at Cornell University. During his Ph.D. work, Callum characterized the queen pheromones of flexibly social sweat bees in Dr. William Wcislo’s research group at the Smithsonian Tropical Research Institute in Panama. In the Kocher lab, he plans to leverage new techniques and a comparative approach across the sweat bee phylogeny to better understand the molecular underpinnings of pheromonal signals and their importance for social evolution.

Ian Traniello

Lewis-Sigler Scholar

Ian is interested in the evolution and maintenance of social organization, beginning with the fundamental question of how a brain “wired” for solitary life can handle the intense push-and-pull of group living. In the Kocher Lab, he explores the neurogenomic architecture of collective and individual behaviors, focusing on molecular correlates of gains and losses of sociality in bees. This focus is subserved by cutting-edge sequencing technologies like single-cell and spatial ‘omics, platforms and analytical pipelines Ian is developing and adapting for bees through close collaboration with the Pritykin Lab at LSI. Ian studied neuroscience and physiology in the Collaborative Degree Program at Boston University, where he earned his joint BS/BA degrees before completing his Neuroscience PhD in Dr. Gene E. Robinson’s lab at the University of Illinois at Urbana-Champaign. Outside of lab, he has over half a decade of experience teaching STEM to incarcerated students, and he is passionate about using science education to build community and create a world without prisons.

Billie Goolsby

Postdoc

Billie is a neuroethologist interested in the evolutionarily convergent and independent neural mechanisms underlying social behavior. More specifically, she studies the molecular substrates that underlie social status ascension and entrenchment. She graduated with a degree in biochemistry and molecular biology from Boston University (B.A. 2019), where she worked with Dr. James Traniello on the neural, physiological, and behavioral impacts of isolation in ants. She then earned her PhD in 2026 from Stanford University, where she studied neural circuits underlying poison frog parental care with Dr. Lauren O’Connell and the evolution of neural cell types across vertebrates (using fish, amphibians, reptiles, birds, and mammals!) with Drs. Lauren O’Connell, Bo Wang, and Liqun Luo. In her free time, she enjoys spending time with her family, watching TV, and hopping around the Bay Area in search of the best restaurants.

Laymon Ball

Postdoc

Charlotte Knopp

EEB Grad Student

Charlotte is broadly interested in how host social structure shapes host-symbiont coevolution. She received her B.A. in Biological Sciences (summa cum laude) from Mount Holyoke College in 2019, where she studied social parasitism in ants and pathogen co-infection in deer ticks. In the Kocher lab, Charlotte studies nematodes of solitary, eusocial, and socially flexible bees, and is particularly interested in how host social structure may push these symbionts across the mutualist-commensal-parasite spectrum. She works with halictid species native to New Jersey and with neotropical halictids at the Smithsonian Tropical Research Institute with Dr. William Wcislo’s research group. Outside of work, Charlotte enjoys ceramics, hiking, climbing, snowshoeing & cross-country skiing, knitting to true-crime podcasts, riding her horse, snuggling with her cat, and teaching her dog new tricks.

Michelle White

EEB Grad Student

Michelle is interested in the behavioral building blocks that precede sociality and other life history traits in insects. By observing pairwise interactions between bees within the Halictidae family, Michelle hopes to reveal the interactive behaviors that exhibit correlated evolution with family traits like time of mating, life expectancy, and sociality. In the Kocher Lab, Michelle will combine field work with phylogenetic comparative methods to infer the evolutionary history and branching patterns of behaviors across Halictidae. Michelle received her B.A. in Biology and B.S.E in Bioengineering from the University of Pennsylvania, where she studied the evolution of queen-worker dimorphism in Formicidae. At Princeton, Michelle hopes to expand her knowledge through teaching and coursework. In her free time, Michelle loves journaling, beadwork, and cooking!

Daniel Jorge

EEB Grad Student

Broadly, Daniel is interested in understanding the evolution of bee societies. This involves questions of “why” would such societies evolve—thus, the selective drivers of sociality—as well as “how” these societies are constructed from an ancestral phenotype—such as the behaviors of a solitary ancestor. As a PhD Student in the Kocher lab, Daniel is building a theoretical framework to investigate how the diverse range of bee societies—communal, semi-social, eusocial, etc.—emerges from the behavior of individuals within colonies. To do this, he is developing a mathematical model of collective organization, with the goal of using the insights from the model to inform and perform new empirical studies.

David Cardona

EEB Grad Student

David received his B.S. in Biology at Universidad del Rosario, Bogotá, Colombia, and completed his undergraduate thesis with Dr. Andre Riveros and Dr. Robert Srygley, studying three-dimensional path integration in leafcutter ants, Atta colombica. Later, as an intern at the Smithsonian Tropical Research Institute in Panama, David worked with Dr. William Wcislo on the endocrine consequences of sociality acquisition in the facultatively social bee Megalopta genalis. As a Ph.D. student in the Kocher Lab, David aims to understand if and how natural selection on ancestral molecular pathways has shaped the neural circuits underlying social behavior in bees.

Fiona Corcoran

EEB Grad Student

Fiona received her BS in Ecology, Evolution, and Biodiversity from the University of Michigan and completed her undergraduate thesis with Dr. Elizabeth Tibbetts working on cognition in Polistes paper wasps. As a graduate student in the Kocher Lab, she plans to investigate the evolution of brains and cognition in bees. She also has an interest in how early life experiences impact brain and cognitive development. In her free time she loves to crochet, cook, and take care of her many houseplants and leopard gecko Penelope.

George Liu

IB Grad Student

Sarthok Rahman

Postdoc

Sarthok is primarily interested in understanding how molecular mechanisms drive the evolution of social complexity, focusing on the fundamental question of how changes in gene regulation enable the transition from solitary to social lifestyles. In the Kocher Lab, he explores the genomic and epigenomic architecture underlying sociality, caste differentiation and behavioral variation in bumblebees, using integrative multi-omics approaches. He is also working towards developing and optimizing reproducible computational pipelines for analyzing gene expression (RNA-seq) and chromatin accessibility (ATAC-seq) data for non-model systems. Previously, he was a postdoctoral fellow in the Lozier Molecular Ecology Lab at the University of Alabama where he studied the genetic and epigenetic basis of the thermal tolerance of montane bumble bees across elevations in the Sierra Cascade Mountain ranges of the American West. Before that, Sarthok earned his PhD working at the Hines Lab of The Pennsylvania State University, where his doctoral dissertation research focused on understanding the ecological and evolutionary genomics of color pattern variation in bumble bees. His doctoral research work led to the novel discovery of the genomic basis of bumble bee coloration and its underlying gene regulatory network, establishing bumble bees as a new model system for pigmentation genetics. Outside of lab, he enjoys cooking and exploring new cuisines, discovering coffee shops, following cricket, reading non-fiction books and mystery thrillers.

Sherry Zhang

Research Specialist

Bees play a pivotal role in maintaining the health of our ecosystems, yet they are facing unprecedented challenges. As a molecular biologist, I am deeply committed to leveraging my expertise to contribute to the bee research community. I aim to apply my knowledge in genetic analysis and molecular markers to address some of the critical issues affecting bee populations today. Additionally, my experience in cell biology, gene editing, primary neuron studies, and mechanical sensing equips me to explore many unsolved mysteries in bee research. Together, we can guide the bee world toward a better future.

Anvita Chaudhary

Molecular Technician

Joanna Shoubaki

Research Specialist

Joanna (Jojo) first joined the Kocher Lab as an undergraduate in Princeton’s Ecology and Evolutionary Biology Department. While there, she completed a thesis exploring how chemical signals may influence social variation in the socially flexible sweat bee, Lasioglossum baleicum. After graduating, she joined the Kocher Lab as a Research Specialist to continue her research into L. baleicum and assist colleagues studying sequence variation and gene expression differences in other bees. She frequently assists in the field and in the lab by collecting specimens, dissecting tissues, and generating genomic libraries of various genera (Bombus, Megalopta, Lasioglossum, etc.). She has also worked with Dr. William Wcislo at the Smithsonian Tropical Research Institute to study the eusocial sweat bees Megalopta genalis’s and M. amoena’s neurobiological profiles and the impacts of a manipulated social environment on their brains. Jojo hopes to later pursue a PhD exploring the environmental and molecular power that drives evolution and behavior.

Dee Ruttenberg

QCB Grad Student

Dee received a BS in Biological Sciences (specializing in genetics) at the University of Chicago. They completed their undergraduate thesis with Dr. Marcus Kronforst on Elymnias hypermnestra, a Batesian mimic whose model varies across a geographic mosaic in Southeast Asia. Using computational genomics, Dee found the genetic factors that underlie E. hypermnestra’s mimicry. It was Dee’s experience taking linguistics courses at UChicago, however, that got them interested in the biology behind communication. As a PhD Student in Quantitative and Computational Biology at Princeton, they are integrating computer vision, genomic, and ecological techniques to better understand how bumblebees make and remake a communication network year after year. This project is currently funded by a NSF GRFP grant. Outside of lab, they love teaching, board games, hiking, Commedia dell’arte, and collecting tchotchke turtles (Chelonia tchotchkeus, seen to the right).

Kennedy Saitoti

EEB Grad Student

Kennedy received his B.S in Biology from University of Nairobi in Kenya. He has an ardent love for insects and has a particular interest in behavior, evolution, and genomics. He found his passion for ecology and evolution while working with researchers studying the African Queen butterfly at the Mpala Research Centre in Kenya. As a graduate student in the Kocher Lab, he is studying the interplay of genes and the environment in regulating and shaping the behavior and physiology of halictid bees.

Nikki van Dorp

Molecular Technician

Nikki received her BSc in Biology and Medical Laboratory Research from University of Applied Science Leiden in the Netherlands. She joined the CUBE lab at the Erasmus MC to help study the way the brain orchestrates motor adaptation and motor learning using functional ultrasound. In the Kocher lab, she is studying the mechanisms that generate variation in social behavior by combining cutting-edge genomic and neurobiological tools with field and lab studies.

Beryl Jones

Postdoc

Beryl is broadly interested in the role of phenotypic plasticity in shaping the evolution of novel traits. She is enamored with social insects, and uses a comparative approach to study the molecular underpinnings of social behaviors in bees. She received a B.S. from the University of Arizona before completing her Ph.D. in Dr. Gene Robinson’s lab at the University of Illinois at Urbana-Champaign, where she studied mechanisms of reproductive plasticity in two bee species. In the Kocher lab, she is excited to integrate behavior and ecology with modern molecular techniques across many species of sweat bees, leveraging the impressive diversity of social behaviors in this group to better understand the mechanisms that influence evolutionary gains and losses of social behavior.

Micah Fletcher

QCB Grad Student

Micah is a PhD student in the Quantitative and Computational Biology program, whose research focuses on the evolution of behavior in treehoppers, a family of hemipteran insects that have gained and lost both maternal care and honeydew-for-protection mutualism with ants multiple times. He earned his B.S. from the University of Missouri – Columbia studying the mechanisms male-male competitive signaling during male-female mate searching duets in treehoppers using plant-borne vibration playback experiments under the direction of Rex Cocroft. Since joining the Kocher Lab, he has been using field experiments, comparative genomics and comparative phylogenetic methods to study how life history and ant mutualism have shaped the evolution of maternal care in treehoppers.

Z. Yan Wang

Postdoc

Yan’s research focuses on the evolutionary neurobiology of social behaviors in invertebrates. She completed her PhD in Dr. Cliff Ragsdale’s lab at the University of Chicago, where she characterized neuroendocrine factors that drive maternal behaviors and death in Octopus bimaculoides. Before that, she studied biology, English literature, and Asian American Studies at Cornell University. In the Kocher Lab, she is excited to investigate the evolution of bee brains and social behaviors.

Ben Rubin

Postdoc

As an undergraduate at Cornell University, Ben’s very first research experiences focused on the behavioral ecology of birds. All the while, and unbeknownst to him, a passionate love for social Hymenoptera was growing within. So when offered the chance to study the population structure of a mutualistic acacia-ant in Kenya under Professor Irby Lovette, he jumped at the chance, beginning his foray into molecular biology and the power of DNA analysis by developing novel microsatellites. This experience fortified his love of Hymenoptera, and, rediscovering a delight for programming not felt since a high school computer science class, Ben completed a PhD on acacia-ant behavioral genomics at the University of Chicago under Field Museum Curator Corrie Moreau. With the purpose of life now clearly defined, he began a postdoc in the Kocher lab using genomics to study a number of aspects of sweat bee biology. Although nearly any use of non-model genomics can now pique Ben’s interest, he focuses on genome evolution, behavioral genomics, and endosymbiont communities. See more at benrubinbiology.com.