SpeciesEvolver: A Landlab component to evolve life in simulated landscapes

Abstract

The surface of the Earth and its biota evolve together. Climate and tectonics ultimately drive the physical and chemical surface processes that evolve landscape structure, including the connectivity of landscape portions that facilitate or impede movement of organismal populations (Antonelli et al., 2018; Stanley, 1979). Impeded organismal movement reduces gene flow among populations and genetic diversity within populations, increasing the probability of species extinction (Bohonak, 1999). Long-term geographic separation of populations (i.e., allopatry) is a mechanism of speciation as populations genetically diverge due to reproductive isolation (Coyne, 1992). Speciation within the same area (i.e., sympatry) can emerge as subpopulations specialize in different resources, and along environmental gradients (e.g., in surface air temperature) where a continuum of reproductive isolation develops, among other proposed mechanisms (Dieckmann & Doebeli, 1999; Doebeli & Dieckmann, 2003). These macroevolutionary processes—dispersal, extinction, and speciation—determine regional biodiversity (Taylor, Fahrig, Henein, & Merriam, 1993).