Selection between Competing Self-Reproducing Lipids: Succession and Dynamic Activation.

Models of chemical evolution are central to advancing origins of life research. To design more life-like systems we must expand our understanding of molecular selection mechanisms. Here we show two selection modes that produce evolving populations of self-reproducing species, formed through thiol-disulfide exchange. Competition between thiol precursors can give clear succession patterns based on steric factors, an intrinsic property. A separate, emergent selection mechanism – dynamic activating metathesis – was found when exploring competing disulfide precursors. These experiments reveal that additional species generated in the mixture open up alternative reaction pathways to form self-reproducing products. Thus, increased compositional complexity provides certain species with a unique competitive advantage at the expense of others.