Dr. Caroline Geisler

Dr. Shai Shaham | Shaham Lab

Bio:
Glial cells are major components of nervous systems, and are in a position to influence nearly every
step of neural information transfer and processing. To understand if and how glia control nervous system
functions, the Shaham lab developed the nematode C. elegans as a unique setting to probe glia-neuron
interactions; demonstrating that glia in this animal can be interrogated without perturbing neuronal viabilityan
important experimental advantage. Using molecular, cell-biological, and physiological tools, developed in part by the Shaham lab group, the lab identified multiple mechanisms by which glia influence nervous system development and function. The Shaham lab showed that the four CEPsh glia of C. elegans are astrocyte-like glia that play central roles in modulating locomotory behavior. The Shaham lab also investigated glia that ensheath sensory-neuron receptive endings, and identified novel signaling interactions with these neurons that control an animal’s response to environmental stimuli. Dr. Shaham will describe recent published and unpublished findings that support the notion that glia play active and critical roles in defining behaviorally consequential activity set points in the nervous system. The lab hypothesizes that many of the rules we describe are conserved across animals, and Dr. Shaham will discuss evidence that
supports this idea.

Shai Shaham received his A.B. degree in biochemistry from Columbia University in 1989. In 1995, he graduated from the Massachusetts Institute of Technology with a Ph.D. in biology. After postdoctoral studies at the University of California, San Francisco, Shaham joined Rockefeller as assistant professor in 2001. He was named associate professor in 2007 and professor in 2012. Shaham was named a Sidney Kimmel Foundation for Cancer Research Scholar and a Rita Allen Foundation Scholar. He has received an Irma T. Hirschl/Monique Weill-Caulier Trust Research Award, a Masin Young Investigator Award from the Breast Cancer Alliance, a Klingenstein Fellowship, The Rockefeller University Distinguished Teaching Award, a Blavatnik Award, and a NINDS Outstanding Investigator Award.

Abstract:
Glial cells are major components of nervous systems and are in a position to influence nearly every step of neural information transfer and processing. To understand if and how glia control nervous system functions, we developed the nematode C. elegans as a unique setting to probe glia-neuron interactions; demonstrating that glia in this animal can be interrogated without perturbing neuronal viability- an important experimental advantage. Using molecular, cell-biological, and physiological tools, developed in part by our group, we identified multiple mechanisms by which glia influence nervous-system development and function. We showed that the four CEPsh glia of C. elegans are astrocyte-like glia that play central roles in modulating locomotory behavior. We also investigated glia that ensheath sensory-neuron receptive endings, and identified novel signaling interactions with these neurons that control an animal’s response to environmental stimuli. Our studies support the notion that glia play active and critical roles in defining behaviorally consequential activity set points in the nervous system. We hypothesize that many of the rules we describe are conserved across animals, and will provide evidence that supports this idea.

Watch the seminar here!

Dr. Valerie Peters | Peters Lab

Bio:
Dr. Valerie Peters is an associate professor of Community Ecology in the Department of Biological Sciences at Eastern Kentucky University. Her research focuses in the areas of agroecology, conservation biology, insect community ecology, plant-animal interactions and tropical ecology. Dr. Peters current research is supported by an NSF CAREER grant, with five years of funding to conduct research and educational outreach in Costa Rica that focuses on the conservation of >700 species of native tropical bees and the pollination services they provide. Dr. Peters is originally from Pennsylvania and graduated with her B.S. in Biology from Pennsylvania State University. After graduating, she wanted to gain a better understanding of real-world issues in conservation biology before deciding on a specific topic for her PhD research. To reach this objective, she decided to combine her passion for ecological science with poverty eradication, and worked for five years, first as an Americorps Volunteer and later, as a Peace Corps Volunteer. As a Peace Corps Volunteer, her work pioneered the successful protection of over 20,000 hectares of land leading to a reserve now known as the La Botija National Park which represents one of the few protected areas in southern Honduras. After Peace Corps, she received her PhD in Ecology from the Odum School of Ecology at the University of Georgia. Her PhD work focused on understanding how to best manage diverse coffee agroforests for bird and bee communities, and was conducted in Costa Rica with funding from the Earthwatch Institute.

Abstract:
Land-maxing in cultivated ecosystems will require a science-based selection of tree species in order for the land to be effective in achieving its multiple goals; e.g. biodiversity conservation and ecosystem integrity, alleviating malnutrition and global inequalities of wealth, and the mitigation of climate change. Plant species are not all equivalent in the number of species they support, and land managers have hundreds or thousands of plant species to choose among. The analysis of ecological networks can be used to quantitatively identify species that are posited to have the strongest impacts on network structure and stability based on their topological role. Once identified, experimental tests of these species’ efficacy in conservation and restoration applications are needed to confirm theory. 

Tropical bees and the pollination services they provide are a critical conservation target yet remain relatively understudied. We empirically quantified tropical bee/butterfly-plant and bee-plant interaction networks and identified the topological roles of all plant species. These networks were constructed across home gardens in a lowland tropical rain forest life zone (years 2017-2019), in 10 agroforestry systems in a tropical premontane life zone (year 2022), and across 30 home gardens spanning an elevational gradient from 200-1500m elevation encompassing three life zones: tropical dry forest, tropical premontane and tropical montane (year 2023). Plant species identified as holding core topological roles from these previous studies are now planted in an experimental restoration study, with data expected to be collected over the next two years.

Dr. Delbert Green II | Green Lab

You can view Dr. Green's CV here!

Abstract:
Monarch butterflies (Danaus plexippus) are renowned for their annual transcontinental migration where they fly thousands of miles each fall to overwinter at specific sites in central Mexico. How did this phenotype evolve? One of our approaches to this question is to study the unique features of monarch migration. The mechanisms (behavioral, genetic, and molecular) required for migrants to perform this trip, particularly to naïvely identify their overwintering sites with remarkably high fidelity, are unknown. I will discuss efforts from our lab that aim to extend our understanding of how this occurs.

Dr. Denis Walsh

Bio:
Denis Walsh is Professor in the Department of Philosophy and the Institute for the History and Philosophy of Science at the University of Toronto. He completed a PhD in Biology at McGill University, Montreal and a PhD in Philosophy at Kings College, University of London. He is author of Organisms, Agency and Evolution (2105 Cambridge University Press)

Abstract:
Philosophers of biology and evolutionary biologists have recently begun to propound the view that organisms are agents and that understanding their agency should have a substantial impact on our understanding of the dynamics of evolution. This suggestion has been met with a fair degree of scepticism and consternation. The objective of this talk is to offer an overview of organismal agency. Questions to be discussed include: In what sense are organisms agents? In what ways might organismal agency alter our conception of evolution? How does organismal agency relate to proposals for an extended evolutionary synthesis? Is the agential perspective consistent with gene-centred modern synthesis thinking about evolution?

Dr. Sangeet Lamichhaney | Lamichhaney Lab

Bio:
Dr. Sangeet Lamichhaney's career has spanned various academic institutions and research topics. After earning his bachelor’s degree in veterinary medicine from Nepal, he completed an Erasmus Mundus Master's program in Molecular Genetics & Bioinformatics in Sweden. His doctoral work at Uppsala University in Sweden under Prof. Leif Andersson focused on the genetics of adaptation in natural populations, studying birds and fish. This work laid the foundation for his future research in adaptive evolution. Following his PhD, Lamichhaney joined Prof. Scott Edwards' lab at Harvard University as a Wenner-Gren research fellow. In 2019, he became an Assistant Professor at Kent State University, where his current research focuses on the genetic basis of adaptation to changing environments, with a particular emphasis on understanding how species evolve in response to environmental stressors. A major highlight of his work is his research in the Galápagos Islands, where he studied Darwin’s finches and their genetic adaptations to diverse food sources, climates, and other ecological factors. By integrating genomic data, he identified key genetic changes in traits such as beak morphology and diet, which are essential to their survival and speciation. Dr. Lamichhaney's research has been published in top-tier journals like Nature and Science and has been featured in prominent media outlets such as the BBC, The New York Times, and National Geographic. He has received several awards, including the Young Investigator Award for Evolutionary Studies and the Hwasser Prize.

Abstract:
Island ecosystems serve as natural laboratories for understanding the molecular mechanisms underlying key evolutionary processes such as adaptive evolution, speciation, and biological invasion. Darwin’s finches, inhabiting the Galápagos Islands, represent one of the most iconic systems for studying these evolutionary processes. As a part of our long-term research in the Galápagos Islands, we have conducted population-scale whole-genome re-sequencing for > 400 individuals of Darwin’s finches and have identified two major genetic mechanisms key to their evolution (1) Two transcription factors, ALX1 and HMGA2, affecting craniofacial development, have driven beak diversification, enabling the finches to utilize a broader range of food resources (2) Extensive interspecific gene flow has been critical in maintaining genetic diversity both within and between species, including a documented case of rapid hybrid speciation. Furthermore, recently, the invasive avian vampire fly (Philornis downsi) has become one of the greatest threats to the Darwin’s finches in Galápagos, that parasitizes their chicks and cause high mortality. We have generated a high-quality reference genome and conducted population-scale whole-genome re-sequencing of P. downsi populations from the Galápagos Islands and mainland Ecuador. Our findings have revealed reduced genetic diversity in Galápagos (indicative of a recent bottleneck), ongoing gene flow among island populations, and positive selection in genes involved in neural signaling, muscle development, and metabolism, traits that have likely facilitated the fly’s successful invasion in Galápagos. Our study offers a framework for investigating the genetic mechanisms underlying species colonization, local adaptation, and dynamics of invasive species within island ecosystems.

Dr. Tania Rozario | Rozario Lab

Bio:
Tania Rozario got her PhD from the University of Virginia studying embryonic development. During her postdoc she joined Phil Newmark's lab (Morgridge Institute for Research, WI) to study planarian regeneration but pivoted toward their parasitic cousins- tapeworms. Her work (re)established the rat tapeworm, Hymenolepis diminuta, as a non-traditional model to explore the molecular mechanisms that govern how tapeworms grow, regenerate, and reproduce at prolific rates. In 2021, she established her independent lab at the University of Georgia where her work understanding extrinsic and intrinsic signals that regulate tapeworm stem cells continues.

Abstract:
Tapeworms grow at rates that rival all metazoan tissues, including during embryonic and neoplastic growth. The rat tapeworm, Hymenolepis diminuta, produces up to 2,200 proglottids (segments), increasing in length up to 3,400 fold, and weight up to 1.8 million fold within the first 15 days of infection. Tapeworms can also regenerate: they shed large parts of their body, releasing their embryos to continue their life cycle, yet are able to continuously replenish proglottids and maintain an equilibrium length. Despite their impressive feats of growth, regeneration-competence is limited to one anatomical region- the neck. Using transcriptomics and RNA interference we have functionally validated the first molecular regulators of tapeworm regeneration and demonstrated that regeneration is dependent on a large population of poorly understood stem cells. Uncovering neck-exclusive stem cell subpopulations that can explain regionally restricted regeneration has remained elusive. Instead, we find that lethally irradiated tapeworms can be rescued from death when cells from both regeneration-competent and regeneration-incompetent regions are transplanted into the neck, suggesting that extrinsic signals at the neck are crucial for regeneration. In pursuit of such signals, we have discovered that the head has an organizer-like function. The head both maintains neck identity and regulates stem cell proliferation by establishing polarized expression patterns of Wnt signaling components like sfrp and beta-catenin. Our work is beginning to elucidate how the head and neck provide a rich signaling environment that enables region-specific regeneration in tapeworms.
 

Dr. Katja Seltmann 

Bio:
Katja Seltmann is the Director of the Cheadle Center for Biodiversity and Ecological Restoration at the University of California, Santa Barbara. The Cheadle Center manages 400 acres of restored habitat in coastal central California and maintains a natural history collection of over half a million specimens. Her research blends data science, digitized collections, and media arts to understand insect biodiversity, conservation, and evolution. Katja is currently leading the "Extending Anthophila Research Through Image and Trait Digitization" (Big-Bee) project, funded by the U.S. National Science Foundation. This multi-year initiative focuses on digitizing bee collections by capturing high-resolution images of bee specimens and creating detailed datasets of their traits. The project involves collaboration with thirteen U.S. institutions and government agencies, aiming to enhance research capabilities and support bee biodiversity conservation efforts.

Abstract:
Functional traits of bees, such as pilosity (hairiness), wing patterns, and dietary preferences, are important for understanding their ecology and evolution. These traits influence pollen collection, pollination efficiency, temperature regulation, and resilience to environmental changes. In this seminar, I will share our work at UC Santa Barbara's Cheadle Center for Biodiversity and Ecological Restoration, where we utilize computer vision and machine learning to analyze high-resolution bee images and large specimen datasets from natural history collections. Our methods offer innovative ways to explore bee biodiversity, including findings that climate and evolutionary history may influence bee hair patterns, that population variations can be detected through wing venation analysis, and that the pollen diet of bees can be predicted based on range size and other factors. Overall, our research provides deeper insights into bee biology and trait evolution and shows potential for improving bee health and conservation monitoring by identifying traits related to resilience and stress.

Watch the seminar here!

Dr. Farrah Madison 

Bio:
Dr. Farrah N. Madison is an Assistant Professor in the Department of Integrative Biology at the University of Wisconsin-Madison, where she leads the Madison Avian Behavioral Neuroendocrinology Lab. She earned her Ph.D. in Poultry Science from the University of Arkansas, Fayetteville, following an M.S. and B.S. in Animal Science from the University of Nebraska, Lincoln. She completed postdoctoral fellowships at Hope College and Johns Hopkins University, where she expanded her expertise in neuroendocrinology and behavioral neuroscience. Dr. Madison’s research explores the neurobiological, genetic, and endocrine mechanisms underlying phenotypic variation in songbirds, particularly focusing on how the endocrine system responds to social and environmental changes. Her work has provided insight into sex, strain, and morph-specific differences in brain plasticity, stress responses, and social behavior, utilizing avian models such as canaries, zebra finches, and Gouldian finches. By integrating molecular, neural, and behavioral approaches, her research seeks to advance our understanding of how hormones and genetic factors shape communication and social behaviors.

Abstract:
Social behaviors, including parental care, territoriality, and mating, vary widely across species, yet the genetic and neurobiological mechanisms regulating these behaviors are often conserved. While numerous studies have investigated gene-behavior associations, few have established direct functional links between genetic variation and individual behavioral differences. Research in my lab takes a comparative approach by leveraging naturally occurring phenotypic variation in songbirds, such as sex and color morphs, to uncover key differences in neurocircuitry, gene expression, and endocrine function that shape complex social behaviors. By integrating behavioral observations with molecular and neuroendocrine techniques, we aim to identify how specific genetic and hormonal factors influence individual differences in complex social behaviors. This work advances our understanding of the mechanisms driving behavioral diversity in avian models and provides broader insights into the conserved genetic pathways underlying social behavior across species.

Watch the seminar here!

Click here for more information on Dr. Joseph Takahashi.