Evolutionary Models: Movement and Mixing in Trait and Physical Space

Over generations, a species will evolve to increase its fitness to its environment. Natural selection is the primary mechanism by which this occurs, wherein environmental pressures cause individuals with more fit phenotypes to reproduce at a higher rate. For the purpose of modeling, the space of possible heritable traits may be viewed as a continuum, and a particular individual as inhabiting a point in trait space. Making the biomass continuous as well, a population is viewed as a distribution in trait space. In this view, natural selection is the process by which the distribution of biomass propagates through trait space, generally increasing its average fitness.