Are you interested in joining our research group? Check out our research interests and send an email to Aaron about opportunities.
Current group members
Aaron Ragsdale, Assistant Professor
I joined the Department of Integrative Biology (now “Biology”) at UW-Madison in Fall 2021.
I am interested in the evolutionary and historical processes that shape
molecular and organismal variation (see our research interests in the lab).
Prior to Wisconsin, I was a postdoc with both
Simon Gravel and
Andres Moreno, and was a graduate student with
Ryan Gutenkunst at the University of Arizona.
Email: apragsdale@wisc.edu
Sumit Sen (Graduate student)
I’m interested in human evolutionary and population genetics. I received my bachelor’s degree in biological sciences at Northwestern University. My work at the Ragsdale Lab is focused on human evolutionary history in deep time and ARG-based inference. I have also previously worked on evaluating methods of controlling for population structure in tests for selection in ancient human DNA.
Email: sumit.sen@wisc.edu
Max Shpak (Research scientist)
Max’s primary research interest is understanding the processes that drive changes in allele frequency and the distribution of quantitative traits under natural selection and neutral evolution. His current project in the lab is a study of the dynamics of underdominant selection on alleles contributing to quantitative traits. He is also pursuing a side project applying diffusion models to approximate the dynamics of frequency-dependent selection.
Email: mshpak@wisc.edu
Santiago Medina, Joint graduate student with the
Andrés Moreno Lab
at LANGEBIO-Cinvestav.
I am a computational biologist. I received my bachelor’s in agro-genomic
sciences from the National Autonomous University of Mexico (UNAM). I am
passionate about evolutionary genetics, and my research centers on
understanding how demographic history shapes genetic diversity in Native
American populations. I love learning mathematics, mainly probability theory.
Outside research, I enjoy meeting with friends, hiking, and practicing
Brazilian Jiu-Jitsu.
Undergraduate researchers
Yufei Zhou (2025-): Data Science major, working on recent population history and linguistics in South America
Jesse (Yixin) Yang (2025-): Biochemistry and Computer Science major, working on protein evolution and mutational robustness
Jiarui (Chris) Gong (2025-): Mathematics and Statistics major, working on protein evolution and mutational robustness
Stavan Sagala (2026-): Computer Science and Statistics major, working on embedding methods in phylogenetic inference
Past members
Epifanía Arango Isaza, Postdoctoral Researcher (2025-2026) – moved on to a Marie Curie postdoctoral fellowship at U Copenhagen
Nathan Anderson, PhD Student (graduated 2026) – moved on to a postdoc with Yuval Simons at U Chicago
Nicholas Collier, Undergraduate and Post-Bac Researcher (2022-2026) – moved on to pursue a PhD in Genetics at UW-Madison
Gustavo Barroso, Postdoctoral Researcher (2022-2026)
Lloyd Kirk, Masters Student (2022-2025)
Undergraduates
Nithya Atla, Undergraduate Researcher (Fall 2024)
Renee Li, Undergraduate Researcher (Fall 2021-Spring 2024)
Vasudha Khanna, Undergraduate Researcher (Fall 2021-Summer 2023)
Linda Zeng, Undergraduate Researcher (Fall 2021-Spring 2023)
Jake Hamburg, Undergraduate Researcher (Spring 2022)