1,721,004 research outputs found
A statistical model of an evolving population with sexual reproduction
No full textWe introduce a statistical model of a population with a sexual reproduction mechanism, evolving in a flat fitness landscape. We show that fluctuations in the genetic overlap between different individuals in the population vanish in the infinite-population limit, contrary to the case of asexual reproduction, which exhibited spin-glass-like behaviour
The selection of altruistic behaviour
No full textAltruistic behaviour is disadvantageous for the individual while is advantageous for its group. If the target of the selection is the individual, one would expect the selection process to lead to populations formed by wholly homogeneous groups, made up of either altruistic or egoistic individuals, where the winning choice depends on the balance between group advantage and individual disadvantage. We show in a simple model that populations formed by inhomogeneous groups can be stabilized in some circumstances. We argue that this condition is realized when there is a relative advantage conferred by the presence of a few altruists to all the members of the group
AN EVOLUTIONARY VERSION OF THE RANDOM ENERGY-MODEL
No full textWe consider Eigen's quasispecies model of molecular evolution in the case in which the reproduction rates of different molecular species are quenched independent random variables. We show, by analogy with the random energy model, the existence of two phases: a 'neutral' phase, where no adaptation effects are exhibited, and a (pathological) 'adapted' phase, where the population is made of identical, optimally adapted molecules, and does not evolve
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