  It has been proposed that during the early steps in the origin of life, small
droplets could have formed via the segregation of molecules from complex
mixtures by phase separation. These droplets could have provided chemical
reaction centers. However, whether these droplets could divide and propagate is
unclear. Here we examine the behavior of droplets in systems that are
maintained away from thermodynamic equilibrium by an external supply of energy.
In these systems, droplets grow by the addition of droplet material generated
by chemical reactions. Surprisingly, we find that chemically driven droplet
growth can lead to shape instabilities that trigger the division of droplets
into two smaller daughters. Therefore, chemically active droplets can exhibit
cycles of growth and division that resemble the proliferation of living cells.
Dividing active droplets could serve as a model for prebiotic protocells, where
chemical reactions in the droplet play the role of a prebiotic metabolism.
