@article{7995,
  abstract     = {When divergent populations are connected by gene flow, the establishment of complete reproductive isolation usually requires the joint action of multiple barrier effects. One example where multiple barrier effects are coupled consists of a single trait that is under divergent natural selection and also mediates assortative mating. Such multiple‐effect traits can strongly reduce gene flow. However, there are few cases where patterns of assortative mating have been described quantitatively and their impact on gene flow has been determined. Two ecotypes of the coastal marine snail, Littorina saxatilis , occur in North Atlantic rocky‐shore habitats dominated by either crab predation or wave action. There is evidence for divergent natural selection acting on size, and size‐assortative mating has previously been documented. Here, we analyze the mating pattern in L. saxatilis with respect to size in intensively sampled transects across boundaries between the habitats. We show that the mating pattern is mostly conserved between ecotypes and that it generates both assortment and directional sexual selection for small male size. Using simulations, we show that the mating pattern can contribute to reproductive isolation between ecotypes but the barrier to gene flow is likely strengthened more by sexual selection than by assortment.},
  author       = {Perini, Samuel and Rafajlović, Marina and Westram, Anja M and Johannesson, Kerstin and Butlin, Roger K.},
  issn         = {15585646},
  journal      = {Evolution},
  number       = {7},
  pages        = {1482--1497},
  publisher    = {Wiley},
  title        = {{Assortative mating, sexual selection, and their consequences for gene flow in Littorina}},
  doi          = {10.1111/evo.14027},
  volume       = {74},
  year         = {2020},
}

@article{1063,
  abstract     = {Severe environmental change can drive a population extinct unless the population adapts in time to the new conditions (“evolutionary rescue”). How does biparental sexual reproduction influence the chances of population persistence compared to clonal reproduction or selfing? In this article, we set up a one‐locus two‐allele model for adaptation in diploid species, where rescue is contingent on the establishment of the mutant homozygote. Reproduction can occur by random mating, selfing, or clonally. Random mating generates and destroys the rescue mutant; selfing is efficient at generating it but at the same time depletes the heterozygote, which can lead to a low mutant frequency in the standing genetic variation. Due to these (and other) antagonistic effects, we find a nontrivial dependence of population survival on the rate of sex/selfing, which is strongly influenced by the dominance coefficient of the mutation before and after the environmental change. Importantly, since mating with the wild‐type breaks the mutant homozygote up, a slow decay of the wild‐type population size can impede rescue in randomly mating populations.},
  author       = {Uecker, Hildegard},
  issn         = {00143820},
  journal      = {Evolution},
  number       = {4},
  pages        = {845 -- 858},
  publisher    = {Wiley-Blackwell},
  title        = {{Evolutionary rescue in randomly mating, selfing, and clonal populations}},
  doi          = {10.1111/evo.13191},
  volume       = {71},
  year         = {2017},
}

@article{990,
  abstract     = {Assortative mating is an important driver of speciation in populations with gene flow and is predicted to evolve under certain conditions in few-locus models. However, the evolution of assortment is less understood for mating based on quantitative traits, which are often characterized by high genetic variability and extensive linkage disequilibrium between trait loci. We explore this scenario for a two-deme model with migration, by considering a single polygenic trait subject to divergent viability selection across demes, as well as assortative mating and sexual selection within demes, and investigate how trait divergence is shaped by various evolutionary forces. Our analysis reveals the existence of sharp thresholds of assortment strength, at which divergence increases dramatically. We also study the evolution of assortment via invasion of modifiers of mate discrimination and show that the ES assortment strength has an intermediate value under a range of migration-selection parameters, even in diverged populations, due to subtle effects which depend sensitively on the extent of phenotypic variation within these populations. The evolutionary dynamics of the polygenic trait is studied using the hypergeometric and infinitesimal models. We further investigate the sensitivity of our results to the assumptions of the hypergeometric model, using individual-based simulations.},
  author       = {Sachdeva, Himani and Barton, Nicholas H},
  issn         = {00143820},
  journal      = {Evolution; International Journal of Organic Evolution},
  number       = {6},
  pages        = {1478 -- 1493 },
  publisher    = {Wiley-Blackwell},
  title        = {{Divergence and evolution of assortative mating in a polygenic trait model of speciation with gene flow}},
  doi          = {10.1111/evo.13252},
  volume       = {71},
  year         = {2017},
}