Physical limits of biological adaptation, interaction, and perception due to individual variations

The field of biological physics has grown from applying physics methods to biological systems to searching for new principles in biological systems that expand the scope of physics. One such principle that uniquely characterizes biological systems is the fact that individuals in any biological population are so diverse in their traits that they cannot be treated as “identical particles”, as often done in physical modeling. Such individual variation has important consequences on the ecology and evolution of biological species. In this talk, I will present work in my group that has looked at several examples of biological processes where individual variations result in various constraints on the extent to which species can adapt to changing environments, persist under species interactions, and perceive patterns from signals. I will first discuss the benefit of population diversity for adaptation in varying environments and show that the benefit can be increased by organisms utilizing external and internal sources of information. Then I will consider predatory interactions between species and show that trait variation within species can lead to unexpected outcomes, such as the predator being able to promote the abundance of the prey rather than reducing it. Finally, I will mention our latest work on mimicry and color perception, where individual variation of display patterns may redefine the criterion of resemblance and explain the “imperfect mimicry problem” in evolution.