ESPCI web site
Emergence of evolution in simple chemical systems
Sustained autocatalysis coupled to compartment growth and division is believed to be a key step in the origin of life. We show that autocatalytic reactions within compartments—when autocatalysis, and reactant and solvent exchange outpace product exchange—drive osmosis and diffusion, resulting in compartment growth. We demonstrate, using the autocatalytic formose reaction compartmentalized in aqueous droplets in an emulsion, that compartment volume can more than double. Competition for a common reactant (formaldehyde) causes variation in droplet growth rate based on the composition of the surrounding droplets. These growth rate variations are partially transmitted after selective division of the largest droplets by shearing, which converts growth-rate differences into differences in droplet frequency. This shows how a combination of properties of living systems (growth, division, variation, competition, rudimentary heredity and selection) can arise from simple physical–chemical processes and may have paved the way for the emergence of Darwinian evolution by natural selection and may represent an important step towards the conception of evolvable synthetic chemical systems.