From chemical reactions to evolution: Emergence of species

¹  Département de Mathématique, Université Notre Dame de la Paix - 8 Rempart de la Vierge, B-5000 Namur, Belgium
²  Dipartimento di Energetica “S. Stecco”, Università di Firenze - via S. Marta 3, I-50139 Firenze, Italy
³  INFN Sezione di Firenze - Firenze, Italy
⁴  Cell and Molecular Biology Department, Karolinska Institute - SE-17177 Stockholm, Sweden

Received: 31 May 2006
Accepted: 9 November 2006

Abstract

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 mechanism 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.