Welcome new faculty: Research Asst. Professor Seppe Kuehn
Seppe Kuehn is an experimental biological physicist who applies the tools of chemical and statistical physics to the study of ecology and evolution. His current research program at the Center for the Physics of Living Cells has two foci: first, to probe how ecosystems respond to well-defined environmental perturbations to uncover general statistical laws that govern behavior at the microscopic level; and second, to study evolution at the single-cell level by looking at how bacterial populations subjected to evolutionary pressures find nutrients in their environment. Kuehn’s approach to biological physics was shaped by colleagues at Rockefeller University, where Keuhn completed his postdoctoral work.
In the laboratory, Kuehn studies bacterial population dynamics and phenotypic evolution under controlled environmental conditions. His experiments will test long-held assumptions in ecology about how ecosystems respond to changes in their environment and the role adaptation plays in these responses. By making careful measurements with bacterial communities Kuehn and his collaborators hope to discover whether stability and adaptation in microbial communities are governed by general statistical laws.
“From physics, we learn that it can be powerful to describe a system’s macroscopic properties rather than each individual interaction,” explains Kuehn. “Think about the laws of thermodynamics, for example: first, we had laws that were inferred empirically from measurements, and though we couldn’t observe at the atomic level why these laws were true, they turned out to be incredibly powerful for understanding and controlling physical systems” explains Kuehn. “Biology is in many ways more complex, but maybe the approach is a valid one: within an ecosystem, you have organisms interacting in complex ways; by studying the emergent properties of the system, it may be possible to infer general laws about ecosystems that would have implications for understanding their dynamics. Such laws might even help us refine our understanding of how the organisms interact on the microscopic level.”
In a second postdoctoral project, Kuehn collaborated with a graduate student to develop high-throughput microscopy for studying microbial behavior, along with a new methodology for quantifying that behavior; using statistical approaches, he and colleagues discovered simple descriptions of immensely complex behavioral phenotypes. At Illinois Kuehn plans to extend these studies by looking at how microbial behaviors adapt under evolutionary pressures. These experiments will explore how behavioral phenotypes at the single-cell level emerge from genetic adaptions and how these adaptations drive variation across a population.
Kuehn received his bachelor’s degree in physics from Beloit College in 2000. He received his doctoral degree in chemical physics from Cornell University in 2007, working under John A. Marohn. Prior to his joining the faculty at Physics Illinois, Kuehn worked as a postdoctoral researcher at Rockefeller University in New York, under Stanislas Leibler in the Laboratory of Living Matter, Center for Studies in Physics and Biology (2007-2013). While there, he contributed to the development of holographic microscopes to obtain precise measurements of population dynamics in microbial communities. He and colleagues together hold a patent for the holographic device (2011).
Kuehn is the recipient of several honors, including a postdoctoral fellowship from the Helen Hay Whitney Foundation (2009-2012). He received a Tunis Wentink Award for Outstanding Doctoral Dissertation (2007) and a Wachter Prize for Excellence in Physical Chemistry (2005), each from the Department of Chemistry and Chemical Biology at Cornell University.
At Illinois, Kuehn is interested in developing a graduate course in quantitative biology with a curriculum that explores statistical physics and evolution using both theoretical and experimental methods. “Statistical tools are becoming increasingly important, especially in biological physics, where high throughput methods from sequencing to phenotyping are becoming standard,” comments Kuehn. “My goal will be to equip students with problem solving abilities and sound strategies for learning from these data and to pique their interest in the remarkable complexities of biological problems.”