Population differentiation and restricted gene flow in Spanish crossbills: Not isolation-by-distance but isolation-by-ecology

P. Edelaar*, D. Alonso, S. Lagerveld, J.C. Senar, M. Björklund

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

54 Citations (Scopus)


Divergent selection stemming from environmental variation may induce local adaptation and ecological speciation whereas gene flow might have a homogenizing effect. Gene flow among populations using different environments can be reduced by geographical distance (isolation-by-distance) or by divergent selection stemming from resource use (isolation-by-ecology). We tested for and encountered phenotypic and genetic divergence among Spanish crossbills utilizing different species of co-occurring pine trees as their food resource. Morphological, vocal and mtDNA divergence were not correlated with geographical distance, but they were correlated with differences in resource use. Resource diversity has now been found to repeatedly predict crossbill diversity. However, when resource use is not 100% differentiated, additional characters (morphological, vocal, genetic) must be used to uncover and validate hidden population structure. In general, this confirms that ecology drives adaptive divergence and limits neutral gene flow as the first steps towards ecological speciation, unprevented by a high potential for gene flow.
Original languageEnglish
Pages (from-to)417-430
Number of pages14
JournalJournal of Evolutionary Biology
Issue number3
Publication statusPublished - Mar 2012
Externally publishedYes


  • Divergent selection
  • Ecological speciation
  • Gene flow
  • Landscape genetics
  • Loxia curvirostra
  • Population divergence
  • Reproductive isolation
  • Resource specialization


Dive into the research topics of 'Population differentiation and restricted gene flow in Spanish crossbills: Not isolation-by-distance but isolation-by-ecology'. Together they form a unique fingerprint.

Cite this