Between migration load and evolutionary rescue: dispersal, adaptation and the response of spatially structured populations to environmental change

Elizabeth C. Bourne*, Greta Bocedi, Justin M. J. Travis, Robin J. Pakeman, Rob W. Brooker, Katja Schiffers

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

44 Citations (Scopus)


The evolutionary potential of populations is mainly determined by population size and available genetic variance. However, the adaptability of spatially structured populations may also be affected by dispersal: positively by spreading beneficial mutations across sub-populations, but negatively by moving locally adapted alleles between demes. We develop an individual-based, two-patch, allelic model to investigate the balance between these opposing effects on a population's evolutionary response to rapid climate change. Individual fitness is controlled by two polygenic traits coding for local adaptation either to the environment or to climate. Under conditions of selection that favour the evolution of a generalist phenotype (i.e. weak divergent selection between patches) dispersal has an overall positive effect on the persistence of the population. However, when selection favours locally adapted specialists, the beneficial effects of dispersal outweigh the associated increase in maladaptation for a narrow range of parameter space only (intermediate selection strength and low linkage among loci), where the spread of beneficial climate alleles is not strongly hampered by selection against non-specialists. Given that local selection across heterogeneous and fragmented landscapes is common, the complex effect of dispersal that we describe will play an important role in determining the evolutionary dynamics of many species under rapidly changing climate.

Original languageEnglish
Article number20132795
Number of pages9
JournalProceedings of the Royal Society of London. B, Biological Sciences
Issue number1778
Early online date22 Jan 2014
Publication statusPublished - 7 Mar 2014


  • allelic model
  • gene flow
  • linkage
  • local adaptation
  • meta-populations
  • black-hole sink
  • climate-change
  • natural-selection
  • gene-flow
  • range expansion
  • phenotypic selection
  • adaptive evolution
  • seed dispersal
  • species range

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