13 papers
Phase transition in a mean-field model for sympatric speciation
V. Schwämmle, K. Luz-Burgoa, J. S. Sá Martins +1
We introduce an analytical model for population dynamics with intra-specific competition, mutation and assortative mating as basic ingredients. The set of equations that describes…
Evolution of polymorphism and sympatric speciation through competition in a unimodal distribution of resources
E. Brigatti, J. S. Sa' Martins, I. Roditi
A microscopic agent dynamical model for diploid age-structured populations is used to study evolution of polymorphism and sympatric speciation. The underlying ecology is represente…
The Coester Line in Relativistic Mean Field Nuclear Matter
A. Delfino, M. Malheiro, V. S. Timoteo +1
The Walecka model contains essentially two parameters that are associated with the Lorentz scalar (S) and vector (V) interactions. These parameters are related to a two-body intera…
Positive mutations and mutation-dependent Verhulst factor in Penna ageing model
S. Moss de Oliveira, D. Stauffer, P. M. C de Oliveira +1
We twice modify the Penna model for biological ageing. First we introduce back (good) mutations and a memory for them into the model. It allows us to observe an improvement of the…
Emergence of Hierarchy on a Network of Complementary Agents
M. Copelli, R. M. Zorzenon dos Santos, J. S. Sa Martins
Complementarity is one of the main features underlying the interactions in biological and biochemical systems. Inspired by those systems we propose a model for the dynamical evolut…
Justification of Sexual Reproduction by Modified Penna Model of Ageing
J. S. Sá Martins, D. Stauffer
We generalize the standard Penna bit-string model of biological ageing by assuming that each deleterious mutation diminishes the survival probability in every time interval by a sm…