Beyond Size Limits: Examining the Biophysical Basis of Multicellular Adaptation

How simple, single-celled organisms evolved into the complex multicellular life forms we see today is one of science's greatest mysteries. Using a unique long-term laboratory evolution experiment with specially engineered yeast, the investigators in this award are watching multicellularity evolve in real-time over thousands of generations. These experiments enable them to directly observe the evolution process. Preliminary data shows that the evolved “snowflake yeast” have already grown from microscopic clusters to centimeter-sized organisms—as large as fruit flies. The yeast has also evolved remarkable abilities including self-generated fluid flows that overcome physical limits on growth, wound healing capabilities that allow them to repair damage, and complex donut-shaped structures that enhance nutrient transport. By combining cutting-edge biophysics, evolutionary biology, and computational modeling, this research reveals the fundamental physical principles that drive the evolution of increasingly complex life forms. The project also includes an innovative educational component that provides research opportunities to high school and undergraduate students, helping us to train the next generation of scientists while advancing our understanding of how life itself becomes more complex. This work has profound implications for understanding the origins of all complex life on Earth, from plants and animals to humans, while demonstrating how physics and evolution work together to create biological innovation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.