Dr. Caroline Geisler

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. 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.

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!

Dr. Chelsea Specht | Specht Lab

Bio:
Dr. Chelsea Specht is the Barbara McClintock Professor of Plant Biology and Associate Director for Faculty Development, Equity, and Inclusion in the School of Integrative Plant Science and serves as the elected Associate Dean of Faculty for Cornell University.   She is a faculty member in the graduate fields of Plant Biology and Ecology and Evolutionary Biology and a faculty fellow of the Atkinson Center for a Sustainable Future.  She is also a member of the L.H. Bailey Hortorium and affiliated with the Cornell University Herbarium. 

In the Specht Lab we work together to investigate the evolution and diversification of Plant Form and Function. We use traditional morphological and developmental techniques combined with molecular genetics, comparative genomics and evolutionary biology to study the natural diversity of plants and to help better understand the forces creating and sustaining this diversity.  Our research incorporates elements of systematics, developmental genetics and molecular evolution to study the patterns and processes associated with plant speciation and diversification.  We take advantage of living and preserved collections to advance our research in plant systematics, biogeography, and developmental evolution. 

Abstract:
Fifty years since Dr. Paul J.M. Maas published his first monograph of the New World Costoideae, we continue to struggle with species boundaries and evolutionary relationships within this charasmatic lineage of tropical monocotyledonous plants.  In fact, the more we explore and discover the more questions emerge about the dynamics, patterns, and processes leading to speciation and diversification across the Neotropical Costaceae.  In this seminar, I will discuss the recent monographic revision and its critical role in establishing a framework for evolutionary and ecological studies of the Neotropical Costus lineage within a phylogenetic context.  The tempo and mode of speciation events are correlated with morphological changes that influence organismal interactions, including pollination and herbivory.  Ecologic, morphologic, and biogeographic conditions that appear to promote hybridization and result in the potential for hybrid speciation are discussed across the genus, and implications for developing a stable taxonomy – and whether or not that is even possible or desirable – will be discussed.

Dr. Jennifer Coughlan | Coughlan Lab

Bio:
See attached CV here.

Abstract:
Determining what factors generate biodiversity is a central question in evolutionary biology. Despite its long history of study, we are only beginning to understand the evolutionary drivers of reproductive barriers between species, including reproductive barriers that manifest as sterile or dead hybrids. An intriguing hypothesis is that intragenomic conflicts- or selfish evolution- can drive the evolution of alleles that cause hybrid sterility/inviability. One such source of conflict is conflict between parents over resource allocation to offspring. Under parental conflict, multiple paternity drives the evolution of paternally derived, resource-acquiring alleles, and maternally derived alleles that distribute resources equally among offspring. In hybrids, mismatches between these parent-of-origin effect alleles can cause inappropriate development of placenta or endosperm, and subsequently embryo death. Here, I test the role of parental conflict in generating one of the most common intrinsic barriers in seed angiosperms- hybrid seed inviability-using members of the evolutionary and ecological model system; the Mimulus guttatus species complex. I show that hybrid seed inviability has evolved rapidly and repeatedly in this group, and patterns of HSI conform to the predictions of parental conflict. Additionally, genetic mapping suggests that hybrid seed inviability is conferred by nuclear, parent-of-origin effect loci (i.e. loci that affect the probability of death only if maternally or paternally derived). Lastly, using a series of natural surveys and mixed pollination crosses, I find that species with different histories of parental conflict frequently co-occur and hybridize, and hybridization between species with differing histories of parental conflict can indirectly influence growth in intraspecific seeds. Overall, this work highlights a dual role of parental conflict in the speciation process; both in the origin of reproductive isolation, but also in the dynamics and outcomes of hybridization in nature.

Watch the seminar here!
 

Dr. Ricardo Mallarino | Mallarino Lab

Bio:
Ricardo Mallarino is an Assistant Professor of Molecular Biology at Princeton University. Originally from Bogota, Colombia, he graduated with a B.S. in Biology from Universidad de los Andes. He completed his graduate studies at Harvard in Organismic and Evolutionary Biology in 2011, working with Arhat Abzhanov on developmental mechanisms underlying beak shape diversity in Darwin’s finches and their close relatives. After completing his PhD. he joined Hopi Hoekstra’s lab at Harvard, where he established a new model species and developed tools for studying the molecular basis of pigment pattern formation in mammals. Research in the Mallarino lab focuses on understanding the genetic and developmental mechanisms by which form and structure are regulated during vertebrate embryogenesis and elucidating how these processes get modified during evolutionary time to produce phenotypic diversity.

Abstract:
The evolution of metazoan organisms over millions of years has led to remarkable complexity of form and function. While biologists have long studied the ultimate causes of biological diversity (i.e., why it originates), the proximate mechanisms underlying its emergence (i.e., how it arises) remain largely unknown. The goal of my lab is to uncover the genetic and developmental mechanisms underlying the establishment of phenotypic traits and to understand how these mechanisms have evolved to generate diversity across species. We achieve this by harnessing naturally evolved phenotypic variation in ‘non-traditional’ species and integrating multiple disciplines, including developmental biology, computational biology, and evolutionary genetics. For the past six years, our research has focused primarily on patterning and evolution of novelty in mammalian skin. In this talk, I’ll describe how my lab has developed new model systems to study two distinct spatially patterned phenomena during skin development - stripe pattern formation in rodents and gliding membrane formation in marsupials. Through the use of experimental embryology, transcriptomics, comparative genomics, and functional genetics, our work has yielded insights into the mechanisms by which phenotypic novelty is generated at the molecular level.

Watch the seminar here!

Dr. Tiago Simões | Simões Lab

Bio:
Dr. Tiago Simões started his career in his home city (Rio de Janeiro, Brazil), where he obtained his BSc and MSc in Biological Sciences- Zoology at the Federal University of Rio de Janeiro and the National Museum of Brazil. He obtained his PhD at the University of Alberta, Canada, in 2018 working with Dr. Michael Caldwell. Between 2019 and 2023 he was a Postdoctoral Fellow at the Museum of Comparative Zoology & Dpt. Organismic and Evolutionary Biology, Harvard University, working with Dr. Stephanie Pierce, and since 2022 a Research Associate in the Division of Vertebrate Zoology at the American Museum of Natural History. Since 2024, he has been an Assistant Professor in the Dpt. Ecology and Evolutionary Biology at Princeton University.

Dr. Simões’s research integrates data from living and extinct species, as well as morphological and genomic data, to investigate deep time problems in vertebrate evolution, with a special focus on the origin and early evolution of lizards and snakes. He has created several new morphological and total-evidence datasets employing state-of-the-art techniques in Bayesian phylogenetics and phylodynamics that helped bridging gaps between morphological and molecular hypothesis of reptile evolution. These studies, along with new technical advances in phylogenetics have been published in several peer-reviewed scientific articles creating, including in Nature, Nature Ecology & Evolution, and Science Advances. 

:
The history of life on Earth is marked by complex interactions between species genomes and phenotypes across constantly changing environments. Therefore, it is necessary to investigate these interactions across deep evolutionary time to understand the processes responsible for the construction of both past and modern biological diversity. However, this line of research has historically faced several logistic and methodological limitations, such as the lack of quantitative methods for combining various data types sampled across vastly different organismal and temporal dimensions. Fortunately, the past decade has been testimony to several advances in Bayesian evolutionary analyses that have fostered the integration of data types towards more sophisticated inferences of evolutionary trees and macroevolutionary dynamics. Here, I will illustrate how I have used and expanded this class of techniques to integrate molecular and phenotypic data from living and fossil species to understand the patterns and processes operating across major evolutionary transitions in vertebrates, with a special focus on reptiles. These results have overhauled the structure of key areas of the reptile tree of life, including the origin of lizards and turtles, the interplay between phenotypic and molecular innovations during evolutionary transitions, and how these events have been impacted by climate change across deep time. I conclude by highlighting how a new omics era, integrating whole genomes and phenomes, can conciliate historical challenges in understanding organismal evolution and the interplay between genomes and phenotypes with their surrounding environments across broad taxonomic and time scales.

Watch the seminar here!

Dr. Susana Magallón Puebla

Bio:
Dr. Susana Magallón Puebla is the Director of the Biology Institute at the Universad Nacional Autónoma de México. She is an evolutionary biologist who focuses on understanding macroevolutionary processes associated to the evolution of flowering plants, including their floral structure, the timing and dynamics of their diversification, and the mechanisms of acquisition of species richness in diverse Mesoamerican lineages. She obtained her B.Sc. and M.SC. degrees from UNAM, and a Ph.D. from the University of Chicago. She held a postdoctoral fellowship at the University of California, Davis. Her research is characterized by a deep understanding and integration of paleobiology and of phylogenetic comparative methods, involving the combination of morphological and molecular data from extant and fossil species. Dr. Magallón was inducted as a member of the National Academy of Sciences (USA)  and the Royal Society (UK) in 2024 because of the quality of her research and contributions to the scientific community.

Abstract:
Integration of molecular data, to provide a general phylogenetic framework, and morphological data, to allow incorporation of fossils, represents a cardinal approach to investigate evolution in deep time. We assembled a morphological matrix for 1201 extant species representing all angiosperm families, and 121 well-preserved fossil flowers, and in combination with a molecular database for extant species based on exemplar representation, used it to investigate methodological issues relating to integration of extant and fossil taxa in phylogenetic estimation; divergence time estimation in a full Total Evidence approach; and estimation of the theoretical floral morphospace. Phylogenetic analyses used different optimization criteria and kinds of data to estimate relationships, as well as uncertainty in fossil placements. We found that the joint use of molecular and morphological data in a parametric context allows to recover a phylogenetic framework in agreement with molecular estimates, and fossils associated to branches in agreement with assessments based on detailed morphological comparisons. Nevertheless, uncertainty associated to fossil placements is usually high. An attempt to estimate divergence times using morphological, molecular and temporal information indicates that, while available models to integrate extant and fossil species in the same diversification process represent significant advances, there are practical difficulties with fossils for which few characters can be scored, and in the free estimation of model parameters. The theoretical morphospace of floral structure was estimated through the construction of a pairwise distance matrix among extant and fossil species, estimation of disparity, and ordination techniques to reduce dimensionality. The area of the theoretical morphospace occupied by extant and fossil species was identified, as well as how morphospace occupation has changed through time and among groups. A decrease in morphospace occupation towards the present and canalization in the of morphospace occupation among derived clades are documented, in agreement with previous independent observations.


How did the first flower in the history of Earth look like?