The Runaway model is an attempt to confront theory in sexual selection with demogenetic dynamics. Can demogenetic models provide the same prediction than analytical optimality models for sexual selection ?
The purpose of this module is to study the joint emergence of tactics for sexual reproduction and evolution of genetic structure.
We model a theoretical population of individuals with genetically coded traits. These traits are: - the total resource that individuals will use for reproduction. It therefore affects further survival and logically the probability to participate in subsequent reproductions (termed as “resource”), - the energy invested in gametes production (termed as “investment”), - the energy invested in phenotype to signal quality (termed as “phenotype”), - the energy invested in preference to be choosy on phenotype (termed as “preference”).
The resource controls the amount of energy that can be invested in gametes, phenotype and preference. A high genetic value of any of these three traits will condition the expression of the two other traits.
Each trait is coded by a number of diploid genes along the genome, and each gene has various effect on the four traits. Through sexual selection and mutation, some variants are maintained, some removed and some created.
Although individuals do not have a gender, reproduction uses sex: the amount of offspring an individual can have is dependent on its investment and the investment of its partner, and the genome of offspring is built through the meiosis principles. Sexual conflict is thus accounted for. One of the interest of the model is also to propose alternative mate choice routine and assess their impact: random mate choice, preference/phenotype based mate choice, and so on.
Because the population is not subdivided in ecologically contrasted environment, there is no adaptation peak. However, there might be some equilibria conditional on all possible tactics in the population and on the genome structure.