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Research article - Peer-reviewed, 2020

Gene flow relates to evolutionary divergence among populations at the range margin

Kanuch, Peter; Kiehl, Berrit; Cassel-Lundhagen, Anna; Laugen, Ane T.; Low, Matthew; Berggren, Asa

Abstract

Background: Morphological differentiation between populations resulting from local adaptations to environmental conditions is likely to be more pronounced in populations with increasing genetic isolation. In a previous study a positive clinal variation in body size was observed in isolated Roesel's bush-cricket, Metrioptera roeselii, populations, but were absent from populations within a continuous distribution at the same latitudinal range. This observational study inferred that there was a phenotypic effect of gene flow on climate-induced selection in this species.Methods: To disentangle genetic versus environmental drivers of population differences in morphology, we measured the size of four different body traits in wild-caught individuals from the two most distinct latitudinally-matched pairs of populations occurring at about 60 degrees N latitude in northern Europe, characterised by either restricted or continuous gene flow, and corresponding individuals raised under laboratory conditions.Results: Individuals that originated from the genetically isolated populations were always bigger (femur, pronotum and genital appendages) when compared to individuals from latitudinally-matched areas characterised by continuous gene flow between populations. The magnitude of this effect was similar for wild-caught and laboratory-reared individuals. We found that previously observed size cline variation in both male and female crickets was likely to be the result of local genetic adaptation rather than phenotypic plasticity.Conclusions: This strongly suggests that restricted gene flow is of major importance for frequencies of alleles that participate in climate-induced selection acting to favour larger phenotypes in isolated populations towards colder latitudes.

Keywords

Adaptive divergence; Body size; Climate; Genetic isolation; Orthoptera

Published in

PeerJ
2020, volume: 8, article number: e10036
Publisher: PEERJ INC

Authors' information

Kanuch, Peter
Slovak Academy of Sciences
Kiehl, Berrit
Swedish University of Agricultural Sciences, Department of Ecology
Kiehl, Berrit
Uppsala University
Cassel-Lundhagen, Anna (Lundhagen, Anna)
Swedish University of Agricultural Sciences, Department of Ecology
Laugen, Ane
Swedish University of Agricultural Sciences, Department of Ecology
Laugen, Ane Timenes (Laugen, Ane Timenes)
Novia University of Applied Sciences
Laugen, Ane
University of Agder
Swedish University of Agricultural Sciences, Department of Ecology
Swedish University of Agricultural Sciences, Department of Ecology

UKÄ Subject classification

Ecology

Publication Identifiers

DOI: https://doi.org/10.7717/peerj.10036

URI (permanent link to this page)

https://res.slu.se/id/publ/108638