The Research Talks provide an opportunity for students and postdocs in the Biology department to present their work to the entire department. We encourage everyone to attend and support these presentations!

The Research Talks provide an opportunity for students and postdocs in the Biology department to present their work to the entire department. We encourage everyone to attend and support these presentations!

The Research Talks provide an opportunity for students and postdocs in the Biology department to present their work to the entire department. We encourage everyone to attend and support these presentations!

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 Shaham will describe recent published and unpublished findings that support the notion that glia play active and critical roles in defining behaviorally consequential activity set points in the nervous system.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. Boris Igic | Igic Lab

Brief Bio:
Professor of Biology at the University of Illinois at Chicago and Research Associate, Field Museum of Natural History.

Abstract:
The vast majority of angiosperms simultaneously produce pollen and ovules. Despite the obvious potential for self-fertilization, most instead predominantly or exclusively cross-fertilize. The most important contrivance used by flowering plants to ensure cross-fertilization is self-incompatibility (SI). SI is a suite of mechanisms that prevents zygote formation by recognizing and rejecting a plant’s own pollen. SI strongly scales effective population sizes and shapes both spatial and temporal distribution of genetic variation. This, in turn, determines the rate of adaptation with far-reaching consequences for the evolution of other traits. 

Nevertheless, SI faces high mutation rate and selection favoring transition from SI to self-compatibility (SC). One-half of angiosperm species are self-fertile, and the transition from SI to SC is one of the best trod evolutionary pathways in flowering plant evolution. Here, I present our recently developed candidate-based, phylotranscriptomic approach for rapid discovery of genes that underly such traits (Ramanauskas and Igic 2021, 2023, Ramanauskas et al. 2025). Using both our original data and a literature review, I discuss the significance of the massive convergence and deep homology of SI, an unusual "meta key innovation" across flowering plants. 

Genetic mechanisms causing SI are complex and varied, but each minimally comprises of a self-recognition reaction between pollen- ("male") and pistil-expressed ("female") genes, leading to a regulatory cascade and death of self-pollen. Remarkably similar--yet clearly distinct and convergent--SI systems have independently evolved many times. And yet, one SI system (RNase-based SI) is extraordinarily widespread and homologous. It has been continually present since the common ancestor of eudicots 120+ My ago, and gave rise to 200,000+ species, nearly 75% of all flowering plants

References

Ramanauskas, K., F.J. Jimenez-Lopez, M. Sanchez-Cabrera, M. Escudero, P.L. Ortiz, M. Arista, and B.Igic. 2025. Rapid Detection of RNase-based Self-incompatibility in Lysimachia monelli (Primulaceae). American Journal of Botany 112:e16449 16pp. https://bsapubs.onlinelibrary.wiley.com/doi/full/10.1002/ajb2.16449

Ramanauskas, K. and B. Igic. 2023. kakapo: Easy extraction and annotation of genes from raw RNA-seq reads. PeerJ e16456 13pp. https://peerj.com/articles/16456/

Ramanauskas, K. and B. Igic. 2021. RNase-based self-incompatibility in cacti. New Phytologist 231:2039-2049. https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/nph.17541

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.

Watch the seminar here!

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?

Watch the seminar here!