Hydrobiologia

, Volume 791, Issue 1, pp 145–154

Effects of interspecific gene flow on the phenotypic variance–covariance matrix in Lake Victoria Cichlids

  • Kay Lucek
  • Lucie Greuter
  • Oliver M. Selz
  • Ole Seehausen
Advances in Cichlid Research II

DOI: 10.1007/s10750-016-2838-z

Cite this article as:
Lucek, K., Greuter, L., Selz, O.M. et al. Hydrobiologia (2017) 791: 145. doi:10.1007/s10750-016-2838-z

Abstract

Quantitative genetics theory predicts adaptive evolution to be constrained along evolutionary lines of least resistance. In theory, hybridization and subsequent interspecific gene flow may, however, rapidly change the evolutionary constraints of a population and eventually change its evolutionary potential, but empirical evidence is still scarce. Using closely related species pairs of Lake Victoria cichlids sampled from four different islands with different levels of interspecific gene flow, we tested for potential effects of introgressive hybridization on phenotypic evolution in wild populations. We found that these effects differed among our study species. Constraints measured as the eccentricity of phenotypic variance–covariance matrices declined significantly with increasing gene flow in the less abundant species for matrices that have a diverged line of least resistance. In contrast, we find no such decline for the more abundant species. Overall our results suggest that hybridization can change the underlying phenotypic variance–covariance matrix, potentially increasing the adaptive potential of such populations.

Keywords

Eccentricity Line of least resistance Hybridization Evolutionary constraints P matrix 

Supplementary material

10750_2016_2838_MOESM1_ESM.eps (330 kb)
Supplementary material 1 (EPS 330 kb)Figure S1 A comparison of trait-by-trait covariances for Pundamilia pundamilia (ellipses in black) and P. nyereri (ellipses in blue) from Makobe Island. Covariances are scaled, hence only the differences in shape are shown. Red asterisks mark instances where the angle of the underlying LLR differs significantly (p < 0.05) between species, whereas green asterisks depict cases where the intercept differs between species. Abbreviations are as follow: BD - body depth, HL - head length, LJL - lower jaw length, LJW - lower jaw width, SnL - snout length, POD - preorbital depth, ChD - cheek depth, EyL - eye length, EyD - eye depth, IOW - interorbital width, POW - preorbital width, SnW - snout width
10750_2016_2838_MOESM2_ESM.docx (38 kb)
Supplementary material 2 (DOCX 38 kb)

Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  • Kay Lucek
    • 1
    • 2
    • 3
  • Lucie Greuter
    • 1
    • 2
  • Oliver M. Selz
    • 1
    • 2
  • Ole Seehausen
    • 1
    • 2
  1. 1.Division of Aquatic Ecology and Evolution, Institute of Ecology and EvolutionUniversity of BernBernSwitzerland
  2. 2.Department of Fish Ecology and Evolution, EAWAG Swiss Federal Institute of Aquatic Science and TechnologyCenter of Ecology, Evolution and BiogeochemistryKastanienbaumSwitzerland
  3. 3.Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK