Institutional Seminar Series
(in person)
Thursday, September 5th, 2024
at Scripps Seaside Forum Auditorium
12 p.m. Talks begin w/ Q&A
Pizza to be served after, will have vegan and gluten free options
-------------------------
Title: Ecological transitions along the water column in marine fishes over deep time
Abstract: Macroevolution has traditionally been studied from the viewpoint of paleontology and paleobiology. However, the increasing availability of time-calibrated molecular trees has more recently fueled the development of novel approaches to studying diversification dynamics and morphological evolution over deep time. My presentation will cover research conducted in my lab, focusing on the implementation of robust phylogenetic trees and their subsequent use in phylogenetic comparative analyses. More specifically, this research focuses on how habitat transitions along the water column have shaped the macroevolutionary trajectory of multiple marine fish groups. Studies covered on these topics include examining how historical mass extinction events, such as the Cretaceous–Paleogene extinction (66 million years ago), have promoted lineage, ecological, and morphological diversification in association with newly released niches along the benthic-pelagic ecological axis. Additionally, they investigate how the repeated origin of water column forms in time and space has led to convergent evolution in body shapes, an outcome driven by deterministic factors. Lastly, while the more uniform water column theoretically provides fewer opportunities for diversification compared to the ecologically and structurally complex bottom habitats, I will present exceptions to this hypothesis, highlighting extraordinary radiations in pelagic habitats. All in all, this research underscores the importance of making robust phylogenetic inferences to address broader questions about macroevolutionary processes.
Bio: Originally from Colombia, Ricardo Betancur-R. began his academic journey in 1994 with a B.Sc. in Marine Biology from Universidad Jorge Tadeo Lozano, followed by an M.Sc. in Marine Biology from Universidad Nacional de Colombia in 2004. In 2004, he moved to the U.S. and completed his Ph.D. in Biological Sciences at Auburn University in 2009. Afterward, he conducted postdoctoral research at The George Washington University until 2013 and was awarded a 2-year Peter Buck Postdoctoral fellowship at the Smithsonian National Museum of Natural History, which he held from 2013 to 2014. From 2014 to 2018, Ricardo was an Assistant Professor at the University of Puerto Rico, Rio Piedras campus, and then at the University of Oklahoma, where he became an Associate Professor in 2023. He is currently an Associate Professor at SIO in the MB division. His research focuses on phylogenetic inference and comparative analysis using fishes as study systems, emphasizing genome-scale approaches for macroevolutionary research. Fieldwork is a key component of his research, with expeditions across four continents.
Title: Enzymes as biocatalysts for sustainable chemistry
Abstract: Enzymes are essential to metabolic processes, from catalyzing life-sustaining mechanisms to constructing chemicals used in ecological relationships. In Nature, enzymes are capable of catalyzing a dazzling diversity of chemical reactions. The ocean specifically is home to specialized enzymes that are often rarely or not found in other environments and perform chemical reactions that are of importance to human and environmental health. We aim to leverage these unique enzymatic reactions in the lab for sustainable chemistry through biocatalysis, or the use of enzymes in chemical synthesis. Of particular interest to my lab are “tailoring” enzymes that decorate a core scaffold that has been built by other enzymes in a pathway. Halogenases are tailoring enzymes that are especially abundant in the marine environment and are capable of installing halogen atoms such as fluorine, chlorine, bromine, and iodine onto carbon atoms, often with precision that is challenging or impossible to achieve with chemical methods alone. In this presentation, I will discuss our work on novel, efficient halogenases from marine cyanobacteria and our plans for their biocatalytic development for sustainable medicinal chemistry.
Bio: April Lukowski is from Bay City, Michigan and developed an interest in enzymes and the environment as an undergraduate student at Saginaw Valley State University, where she completed a B.S. in Biochemistry in 2015. She then continued her education at the University of Michigan for her Ph.D. in Chemical Biology with Alison Narayan studying the biosynthesis of saxitoxin in cyanobacteria and the application of enzymes in biocatalysis. In Fall 2020, April started her postdoc with Bradley Moore at SIO to study genome mining and the biosynthesis of halogenated toxins. April launched her own research group at UC San Diego at the Scripps Institution of Oceanography and the Skaggs School of Pharmacy and Pharmaceutical Sciences in Fall 2023, where her lab focuses on the discovery of novel enzymes from natural product biosynthetic pathways and their applications as biocatalysts in medicinal chemistry.
*talks will not be recorded