Thermally driven fission of protocells.

We propose a simple mechanism for the self-replication of protocells. Our main hypothesis is that the amphiphilic molecules composing the membrane bilayer are synthesized inside the protocell through exothermic chemical reactions. The slow increase of the inner temperature forces the hottest molecules to move from the inner leaflet to the outer leaflet of the bilayer. Because of this outward translocation flow, the outer leaflet grows faster than the inner leaflet. This differential growth increases the mean curvature and amplifies any local shrinking of the protocell until it splits in two. The proposed model, based on mere laws of physics, is a step in the study of the origin of life, as well as a clue for a better understanding of cell proliferation in cancer.