Genomic Contingencies and the Potential for Local Adaptation in a Hybrid Species

Research output: Contribution to journalArticle


Hybridization is increasingly recognized as a potent evolutionary force. Although additive genetic variation and novel combinations of parental genes theoretically increase the potential for hybrid species to adapt, few empirical studies have investigated the adaptive potential within a hybrid species. Here, we address whether genomic contingencies, adaptation to climate, or diet best explain divergence in beak morphology using genomically diverged island populations of the homoploid hybrid Italian sparrow Passer italiae from Crete, Corsica, and Sicily. Populations vary significantly in beak morphology both between and within islands of origin. Temperature seasonality best explains population divergence in beak size. Interestingly, beak shape along all significant dimensions of variation was best explained by annual precipitation, genomic composition, and their interaction, suggesting a role for contingencies. Moreover, beak shape similarity to a parent species correlates with proportion of the genome inherited from that species, consistent with the presence of contingencies. In conclusion, adaptation to local conditions and genomic contingencies arising from putatively independent hybridization events jointly explain beak morphology in the Italian sparrow. Hence, hybridization may induce contingencies and restrict evolution in certain directions dependent on the genetic background.


  • Anna Runemark
  • Laura Piñeiro Fernández
  • Fabrice Eroukhmanoff
  • Glenn Peter Sætre
External organisations
  • University of Oslo
  • University of Zurich
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Evolutionary Biology
  • Genetics
Original languageEnglish
Pages (from-to)10-22
JournalAmerican Naturalist
Issue number1
Early online date2018 Apr 23
Publication statusPublished - 2018
Publication categoryResearch