Limited genetic parallelism underlies recent, repeated incipient speciation in geographically proximate populations of an Arctic fish (Salvelinus alpinus)

Sarah J. Salisbury* (Corresponding Author), Gregory R. McCracken, Robert Perry, Donald Keefe, Kara Layton, Tony Kess, Cameron M. Nugent, Jong S. Leong, Ian R. Bradbury, Ben F Koop, Moira M. Ferguson, Daniel E. Ruzzante

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)


The genetic underpinnings of incipient speciation, including the genomic mechanisms which contribute to morphological and ecological differentiation and reproductive isolation, remain poorly understood. The repeated evolution of consistently, phenotypically distinct morphs of Arctic Charr (Salvelinus alpinus) within the Quaternary period offer an ideal model to study the repeatability of evolution at the genomic level. Sympatric morphs of Arctic Charr are found across this species' circumpolar distribution. However, the specific genetic mechanisms driving this morph differentiation are largely unknown despite the cultural and economic importance of the anadromous morph. We used a newly designed 87k SNP chip to investigate the character and consistency of the genomic differences among sympatric morphs within three recently deglaciated and geographically proximate lakes in Labrador, Canada. We found genetically distinct small and large morph Arctic Charr in all three lakes consistent with resident and anadromous morphs, respectively. A degree of reproductive isolation among sympatric morphs is likely given genome‐wide distributions of outlier SNPs and high genome‐wide FSTs. Across all lakes, outlier SNPs were largely nonoverlapping suggesting a lack of genetic parallelism driving morph differentiation. Alternatively, several genes and paralogous copies of the same gene consistently differentiated morphs across multiple lakes suggesting their importance to the manifestation of morphs. Our results confirm the utility of Arctic Charr as a model for investigating the predictability of evolution and support the importance of both genetic parallelism and nonparallelism to the incipient speciation of Arctic Charr morphs.
Original languageEnglish
Pages (from-to)4280-4294
Number of pages15
JournalMolecular Ecology
Issue number22
Early online date3 Oct 2020
Publication statusPublished - Nov 2020

Bibliographical note

Funding Information:
Thanks go to S. Avery, J. Callahan, S. Hann, L. Pike, R. Solomon for their indispensable help with fieldwork. We greatly appreciate Parks Canada for allowing us access to the Torngat Mountains National Park and the Nunatsiavut government for allowing us to access their lands for sampling. Thanks to A. Belay at Mount Sinai Hospital for her help with sequencing, to A. Mesmer for her help with genotyping, and to S. Lehnert for her insightful suggestions on our data analysis. We also greatly appreciate the help of our Editor and three anonymous reviewers whose comments greatly improved this work. We also thank the Institute for Biodiversity, Ecosystem Science, and Sustainability of the Department of Environment and Conservation of the Government of Labrador and Newfoundland for funding for this project; NSERC for the Strategic Grant STPGP 430198 and Discovery Grant awarded to DER, for the CGS‐D awarded to SJS; the Killam Trust for the Level 2 Izaak awarded to SJS; and the Government of Nova Scotia for the Graduate Scholarship awarded to SJS.


  • SNP
  • incipient speciation
  • morph
  • parallelism
  • paralogues


Dive into the research topics of 'Limited genetic parallelism underlies recent, repeated incipient speciation in geographically proximate populations of an Arctic fish (Salvelinus alpinus)'. Together they form a unique fingerprint.

Cite this