Life on Earth is predominantly microbial; complex microbial ecosystems run our planet and shape our health. Thanks to a recent technological revolution, we are discovering that our macroscopic intuition about evolution and ecology is faltering at the microbial scale, making us question some of the most basic concepts, such as "species," "fitness," and even "organism." But how else could we describe these systems, if not in these terms? I will argue that this exciting challenge is one where the methods of theoretical physics have the most to contribute. I will then discuss one way to make this intriguing question precise, investigating simple mathematical models whose large-N regime can be seen as describing both ecological and evolutionary phenomena. This approach blurs the boundary between a simple ecosystem and a complex organism, and may pave the road towards non-discrete generalizations of the familiar discrete notions.
Wtr. Qtr. Colloq. committee: A. Linde (Chair), S. Kivelson, B. Lev, S. Zhang
Location: Hewlett Teaching Center, Rm. 201