Modelling Gene Flow and Population Dynamics in an Age-structured
Population
Lars Rönnegård
Dept of Animal Breeding and Genetics, Swedish University of
Agricultural Science, Sweden
Abstract
Population dynamics describes the change of population size over time, while gene flow is the process of gene inheritance between sub-groups in a population. When generations overlap, genetic improvement in a selected group of animals in one year is not immediately passed through the population, as it is if generations are discrete. A deterministic gene flow model was developed by Hill for modelling how genetic gain from selection in an age-structured population spread through age-classes in domestic animal populations. Hill's model is a matrix model corresponding to Leslie matrix models of population dynamics, and have mathematical properties in common. Hill's model has now been further developed by Rönnegård to analyse the effects of male migration on observed calf body weight differences between a selected and an unselected reindeer herd. In a reindeer herd the age-structure varies between years and, therefore, Hill's model has been extended to include effects of population dynamics on gene flow, by connecting the model to Leslie matrix models. Hill's model has also been developed so that inherited maternal influences, besides direct genetic effects, can be simulated.
