Active motility and navigation strategies at the microscale
At the microscopic scale, virtually everything moves. From diverse patterns of movement one can distinguish living from non-living matter, bacteria from eukaryotes, random from directed, purposeful movement. I will discuss our recent work on phenotyping the motility of diverse microeukaryotes from long-time trajectory statistics. These include swimmers that orchestrate propulsion-generating appendages (cilia and flagella) for propulsion through fluids, as well as organisms that glide mysteriously without the need to resort to any appendages at all. We derive species-agnostic measures of active motility from high-speed live imaging experiments and show how to distinguish between distinct yet stereotyped states (or gaits) of activity. Relating behavioural motifs with intracellular signalling (e.g. bioelectrical activity) we attempt to understand the origins of biological communication in aneural organisms.