Title
Sexual Selection Promotes Ecological Speciation in Digital Organisms
Authors
Rosangela Canino-Koning, Jason Keagy, Charles Ofria
Schedule
Date: Wednesday 6 Sept
Talk Time: TBA
Session: Ecological and evolutionary dynamics 10:30
Keywords
digital evolution, speciation, sexual selection, evolution, ecological speciation, pre-mating isolation, pre-zygotic isolation, divergent adaptation, avida
Abstract
Ecological Speciation is the development of reproductive isolation as a result of divergent adaptation to different environments. As populations diverge, post-zygotic isolation effects such as hybrid unfitness and zygotic inviability are expected to become increasingly dominant. However, for genetically similar incipient species, post-zygotic effects may not be sufficient to enforce a reduction in gene-flow. Models of allopatric speciation predict that pre-mating isolation may play an important role in reinforcing barriers between species, regardless of genetic incompatibilities. However, evidence for these models is mixed, and remain controversial. In this paper, we examine the extent to which pre-mating isolation resulting from divergent sexually-selected traits is sufficient to generate incipient species. We evolved populations of sexually-reproducing digital organisms that use sexual selection to choose their mates. These populations are then divided, and each half allowed to adapt to divergent environmental conditions (allopatry). We then reunited these populations for a single round of mating and measured the rate of hybridization. We found that sexual selection significantly reduces the number of hybrid matings between populations. Further, we found that post-zygotic effects were only are minimally present, despite adaptation to distinct environments, and that there was little difference in both pre-mating and post-zygotic effects between distinct sets of environments. We conclude that sexual selection is a strong force for generating incipient species, even while post-zygotic effects have minimal impact.
