Rapid formation of distinct hybrid lineages after secondary contact of two fish species (Cottus sp.)

  • Stemshorn K
  • Reed F
  • Nolte A
 et al. 
  • 109

    Readers

    Mendeley users who have this article in their library.
  • 35

    Citations

    Citations of this article.

Abstract

Homoploid hybridization after secondary contact between related species can lead to mixtures of genotypes which have the potential for rapid adaptation to new environmental conditions. Here, we focus on a case where anthropogenic changes within the past 200 years have allowed the hybridization between two fish species (Cottus rhenanus and Cottus perifretum) in the Netherlands. Specifically, we address the question of the dynamics of the emergence of these hybrids and invasion of the river systems. Using a set of 81 mostly ancestry-informative SNP markers, as well as broad sample coverage in and around the area of the initial contact, we find a structured hybrid swarm with at least three distinct hybrid lineages that have emerged out of this secondary contact situation. We show that genetically coherent groups can occur at geographically distant locations, while geographically adjacent groups can be genetically different, indicating that some form of reproductive isolation between the lineages is already effective. Using a newly developed modelling approach, we test the relative influence of founding admixture, drift and migration on the allele compositions of the sampling sites. We find that the allele frequency distributions can best be explained if continued gene flow between the parental species and the hybrid lineages is invoked. Genome mapping of the invasive lineage in the Rhine shows that major chromosomal rearrangements were not involved in creating this distinct lineage. Our results show that hybridization after secondary contact can quickly lead to multiple independent new lineages that have the capacity to form hybrid species.

Author-supplied keywords

  • Cottus
  • adaptation
  • hybridization
  • speciation

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

Error loading document authors.

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free