Clusters of incompatible genotypes evolve with limited dispersal

Area of Science:

• Evolutionary Biology
• Population Genetics
• Landscape Genetics

Background:

• Heterogeneous selection is considered a primary driver of reproductive isolation in continuous populations.
• The role of limited dispersal in isolation, independent of selection or geography, remains less understood.

Purpose of the Study:

• To investigate if limited dispersal alone can lead to reproductive isolation in the absence of geographic barriers and heterogeneous selection.
• To explore the influence of different dispersal strategies on the evolution of reproductively isolated genotypes.

Main Methods:

• Utilized a spatially-explicit, individual-based landscape genetics program.
• Simulated genetic structure in a continuously distributed population across various dispersal strategies.
• Varied the number of potential mating partners within the population (20 to 5000 individuals).

Main Results:

• Short-range dispersal strategies resulted in the evolution of reproductively isolated genotype clusters.
• These isolated clusters persisted when the number of mating partners was restricted (below approximately 350 individuals).
• Geographic barriers and heterogeneous selection were not required for the emergence of reproductive isolation.

Conclusions:

• Limited dispersal can be a significant factor in the early stages of speciation.
• The number of mating partners plays a critical role in maintaining reproductive isolation driven by dispersal.
• Further research should examine gene flow heterogeneity and spatial selection gradients in speciation.