Motility of microscopic swimmers as protocells

Encoding life-like behavior in prebiotically plausible compartments, for example growth and reproduction, has been a major focus of protocell research. We argue that, in addition to these essential features of dynamic protocellular systems, motility could have also contributed to a significant degree in the emergence, survival, and complexification of protocells because it would endow these compartments with autonomous behavior and with the possibility to adapt to the environment. Therefore, we have looked into plausible mechanisms by which motility can be imparted to synthetic compartments in fluids, with a special focus on the prebiotic relevance of these compartments. The discussion is organized based on salient features of motile behavior, such as random walk, gravitaxis, chemotaxis, predator-and-pray, stop-and-go, and helical trajectories. In the conclusion, we suggest a motility-based scenario for the formation of stable vesicles from early lipids. The sophisticated movement of these compartments in aqueous environements could also find applications in healthcare, e.g., to deliver cargo.