Emergence of species in a Chemoton-like model: Technical issues.

The Chemoton model constitutes a minimalistic description of a protocell unit. The original formulation assumes three coupled chemical networks, representing a proto' metabolism, a template duplication and the membrane growth. An improved version is here proposed that explicitly incorporates the effects of the volume changes, due to the membrane growth. A stochastic mechanisms is also introduced that mimics a stochastic source of error in the template duplication process. Numerical simulations are performed to monitor the time evolution of a family of protocells, under the chemoton hypothesis. An open'ended Darwinian evolution under the pressure of the environment is reproduced thus allowing to conclude that differentiation into species is an emergent property of the model.