We try to understand the “rules of the game” that explain how cells function and evolve. We study budding yeast, using experimental evolution, genetic analysis, synthetic biology, and cell biology. We try to make quantitative measurements that discriminate amongst different classes of models. Members of the lab come from both biology and physics backgrounds.
How does biological novelty evolve? Because we lack time travel, this process is difficult to study in nature, and we therefore apply selective pressure in the laboratory. We have evolved multicellularity, altered mating preferences, circadian oscillators, genetic instability, and new connections between signaling pathways and have developed methods to find the mutations that cause these new phenotypes. We are interested both in general questions about what determines evolutionary trajectories and the specific mechanisms that organisms invent to produce novel traits.
How do cells accomplish specific tasks and how did these solutions evolve? We follow the Feynman principle of “What I cannot create, I cannot understand” by engineering and analyzing the behavior of new yeast strains. As examples, we have used synthetic biology to support the notions that the efficient use of secreted public goods drove the evolution of multicellularity, that multicellularity arose before cellular differentiation, and that novel symbioses could arise without requiring previous evolutionary co-adaptation.
How do cells respond and adapt to their environment to maximize the chance that they survive and reproduce? Achieving these aims requires the coordination of thousands of reactions under a wide range of inter- and extracellular conditions. We are exploring how yeast cells respond to sudden starvation and have discovered that they can rapidly halt their cell cycles, at any stage, and then, later, slowly resume cell division. We are asking how they arrest, whether the arrest destabilizes the genome, and how cells adapt to start dividing again.
Finally, we collaborate with David Nelson (Physics and MCB) to combine theory and experiment to investigate population dynamics and evolution in space and time.
New Course Information: LS50 a/b: Integrated Science
For much of the 20th century, the different branches of science were seen as separate: biologists studied biology, chemists studied chemistry, and physicists studied physics. In the 21st century, the distinctions have blurred: scientists who try to understand living systems combine tools and approaches from biology, chemistry, computer science, mathematics, and physics to reach a level of knowledge that satisfies our curiosity and tackles pressing problems that face humankind, and scale and precision of the biochemical and biophysical machines that keep cells alive inspires engineers to design new materials and principles for creating devices. We aim to mimic this fusion of disciplines in an intensive, year-long, double course that will teach a small group of students the natural sciences as an integrated whole, incorporating the key principles in biology, chemistry, and physics, providing them with the mathematical tools needed to think quantitatively about scientific problems, introducing them to experimental computation as a way of building understanding, and allowing them to do original research projects in well-equipped labs. In looking for the first wave of students, who will both take the course and contribute to shaping it for their successors, we are more concerned with students' enthusiasm and motivation than we are with their level of academic preparation. The faculty teaching the course would be delighted to talk to entering students who would be interested in taking the course.
For more information (intranet): https://canvas.harvard.edu/courses/3013
Course Description and SyllabusLS50 Course Description pdf