title: Effect of migration in a diffusion model for template coexistence in protocells.
abstract: The compartmentalization of distinct templates in protocells and the exchange of templates between them (migration) are key elements of a modern scenario for prebiotic evolution. Here we use the diffusion approximation of population genetics to study analytically the steady-state properties of such a prebiotic scenario. The coexistence of distinct template types inside a protocell is achieved by a selective pressure at the protocell level (group selection) favoring protocells with a mixed template composition. In the degenerate case, where the templates have the same replication rate, we find that a vanishingly small migration rate suffices to eliminate the segregation effect of random drift and so to promote coexistence. In the nondegenerate case, a small migration rate greatly boosts coexistence as compared with the situation where there is no migration. However, increase of the migration rate beyond a critical value leads to the complete dominance of the more efficient template type (homogeneous regime). In this case, we find a continuous phase transition separating the homogeneous and the coexistence regimes, with the order parameter vanishing linearly with the distance to the transition point.
authors.affiliation: Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, SP, Brazil, fontanari@ifsc.usp.br.
authors.forename: José F
authors.initials: JF
authors.lastname: Fontanari
authors.forename: Maurizio
authors.initials: M
authors.lastname: Serva
mesh_terms: D000465:Algorithms; D058045:Artificial Cells / Q000378:metabolism; D005075:Biological Evolution; D002465:Cell Movement; D002468:Cell Physiological Phenomena; D004058:Diffusion; D055641:Mathematical Concepts; D008954:Models, Biological; D000069497:Origin of Life; D049490:Systems Biology