Competitive Exclusion Principle among Synthetic Non-Biochemical Protocells

Essential for Darwin’s “struggle for existence,” the competitive exclusion principle (CEP) states that any “two species occupying the same niche will compete with each other to the detriment of one of the species, which will thus be excluded.” Here, we report on competition experiments between two populations of autonomous, artificial, self-booting, self-reproducing polymer-based protocells emerging from a homogeneous blend of small synthetic chemicals in a one-pot reactor using polymerization-induced self-assembly (PISA). These protocells are carbon chemistry based but biochemistry free. The populations share their environment, differing only in that one contains a photocatalyst that confers advantages in reproduction. Competition in the shared environment follows the CEP. Thus, biochemistry is sufficient, not necessary, to drive the CEP. This has implications for protocell research, the origin and early evolution of life, and the laboratory synthesis of life and also relaxes constraints for the potential presence and evolution of generalized life in exoplanets.