Adaptive introgression during environmental change can weaken reproductive isolation


Anthropogenic climate change is an urgent threat to species diversity1,2. One aspect of this threat is the merging of species through increased hybridization3. The primary mechanism for this collapse is thought to be the weakening of ecologically mediated reproductive barriers, as demonstrated in cases of ‘reverse speciation’4,5. Here, we expand on this idea and show that adaptive introgression between species adapting to a shared, moving climatic optimum can readily weaken any reproductive barrier, including those that are completely independent of climate. Using genetically explicit forward-time simulations, we show that genetic linkage between alleles conferring adaptation to a changing climate and alleles conferring reproductive isolation (intrinsic and/or non-climatic extrinsic) can lead to adaptive introgression facilitating the homogenization of reproductive isolation alleles. This effect causes the decay of species boundaries across a broad and biologically realistic parameter space. We explore how the magnitude of this effect depends on the rate of climate change, the genetic architecture of adaptation, the initial degree of reproductive isolation, the degree to which reproductive isolation is intrinsic versus extrinsic and the mutation rate. These results highlight a previously unexplored effect of rapid climate change on species diversity.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: An example simulation with Δ = 1.5 illustrating climate-driven adaptive introgression.
Fig. 2: The effect of simulation parameters on RI loss.
Fig. 3: Hybridization enhances adaptation at high rates of climate change.

Data availability

The authors declare that data supporting the findings of this study are available within the article, its supplementary information files and at

Code availability

All code for the underlying simulations is available at


  1. 1.

    Thomas, C. D. et al. Extinction risk from climate change. Nature 427, 145–148 (2004).

  2. 2.

    Hoffmann, A. A. & Sgrò, C. M. Climate change and evolutionary adaptation. Nature 470, 479–485 (2011).

  3. 3.

    Todesco, M. et al. Hybridization and extinction. Evol. Appl. 9, 892–908 (2016).

  4. 4.

    Chunco, A. J. Hybridization in a warmer world. Ecol. Evol. 4, 2019–2031 (2014).

  5. 5.

    Vonlanthen, P. et al. Eutrophication causes speciation reversal in whitefish adaptive radiations. Nature 482, 357–362 (2012).

  6. 6.

    Oliveira, R., Godinho, R., Randi, E. & Alves, P. C. Hybridization versus conservation: are domestic cats threatening the genetic integrity of wildcats (Felis silvestris silvestris) in Iberian Peninsula? Phil. Trans. R. Soc. Lond. B 363, 2953–2961 (2008).

  7. 7.

    Taylor, E. B. et al. Speciation in reverse: morphological and genetic evidence of the collapse of a three-spined stickleback (Gasterosteus aculeatus) species pair. Mol. Ecol. 15, 343–355 (2006).

  8. 8.

    Abbott, R. et al. Hybridization and speciation. J. Evol. Biol. 26, 229–246 (2013).

  9. 9.

    Barton, N. H. Does hybridization influence speciation? J. Evol. Biol. 26, 267–269 (2013).

  10. 10.

    Seehausen, O. Conditions when hybridization might predispose populations for adaptive radiation. J. Evol. Biol. 26, 279–281 (2013).

  11. 11.

    Gómez, J. M., González-Megías, A., Lorite, J., Abdelaziz, M. & Perfectti, F. The silent extinction: climate change and the potential hybridization-mediated extinction of endemic high-mountain plants. Biodivers. Conserv. 24, 1843–1857 (2015).

  12. 12.

    Barton, N. & Bengtsson, B. O. The barrier to genetic exchange between hybridising populations. Heredity 57, 357–376 (1986).

  13. 13.

    Bank, C., Bürger, R. & Hermisson, J. The limits to parapatric speciation: Dobzhansky–Muller incompatibilities in a continent–island model. Genetics 191, 845–863 (2012).

  14. 14.

    Lindtke, D. & Buerkle, C. A. The genetic architecture of hybrid incompatibilities and their effect on barriers to introgression in secondary contact. Evolution 69, 1987–2004 (2015).

  15. 15.

    Mallet, J. Hybridization as an invasion of the genome. Trends Ecol. Evol. 20, 229–237 (2005).

  16. 16.

    Pespeni, M. H. et al. Evolutionary change during experimental ocean acidification. Proc. Natl Acad. Sci. USA 110, 6937–6942 (2013).

  17. 17.

    Hendry, A. P., Farrugia, T. J. & Kinnison, M. T. Human influences on rates of phenotypic change in wild animal populations. Mol. Ecol. 17, 20–29 (2008).

  18. 18.

    Lynch, M. & Lande, R. in Biotic Interactions and Global Change (eds Kareiva, P. M. et al.) 234–250 (Sinauer, 1993)

  19. 19.

    Bürger, R. & Lynch, M. Evolution and extinction in a changing environment: a quantitative-genetic analysis. Evolution 49, 151–163 (1995).

  20. 20.

    Kingsolver, J. G. et al. The strength of phenotypic selection in natural populations. Am. Nat. 3, 245–261 (2001).

  21. 21.

    Gienapp, P., Leimu, R. & Merilä, J. Responses to climate change in avian migration time—microevolution versus phenotypic plasticity. Clim. Res. 35, 25–35 (2007).

  22. 22.

    Merilä, J. & Hoffmann, A. A. in Oxford Research Encyclopedia of Environmental Science (Oxford Univ. Press, 2016)

  23. 23.

    Exposito-Alonso, M. et al. Genomic basis and evolutionary potential for extreme drought adaptation in Arabidopsis thaliana. Nat. Ecol. Evol. 2, 352–358 (2018).

  24. 24.

    Osborne, E., Richter-Menge, J. & Jeffries, M. Arctic Report Card 2018 (NOAA Arctic Program, 2018);

  25. 25.

    Haller, B. C. & Messer, P. W. SLiM 3: forward genetic simulations beyond the Wright–Fisher model. Mol. Biol. Evol. 36, 632–637 (2018).

  26. 26.

    Bateson, W. in Darwin and Modern Science (ed. Seward, A. C.) 85–101 (Cambridge Univ. Press, 1909).

  27. 27.

    Dobzhansky, T. H. Studies on hybrid sterility. II. Localization of sterility factors in Drosophila pseudoobscura hybrids. Genetics 21, 113–115 (1936).

  28. 28.

    Muller, H. J. Isolating mechanisms, evolution, and temperature. Biol. Symp. 6, 71–125 (1942).

  29. 29.

    Gingerich, P. D. Quantification and comparison of evolutionary rates. Am. J. Sci. 293, 453–478 (1993).

  30. 30.

    R Core Team R: A Language and Environment for Statistical Computing (R Foundation for Statistical Computing, 2018);

  31. 31.

    Wickham, H. ggplot2: Elegant Graphics for Data Analysis (Springer, 2016)

Download references


This work was supported by an NSERC Banting Postdoctoral Fellowship to G.O. and an NSERC Postdoctoral Fellowship to K.S. G.O. was also supported by postdoctoral funding from R. Nielsen at UC Berkeley, while K.S. was further supported by postdoctoral funding and good vibes from M. Noor at Duke University. R. Nielsen, M. Osmond, K. Ostevik and L. Rieseberg provided helpful feedback and discussions on earlier versions of the manuscript. We thank P. Messer and B. Haller for assistance with the SLiM 3.X software.

Author information

G.O. and K.S. designed the study, created the model, analysed the results and wrote the paper.

Correspondence to Gregory L. Owens.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Climate Change thanks Simon Martin, Joshua Miller and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary discussion, Figs. 1–3 and Tables 1–5.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Owens, G.L., Samuk, K. Adaptive introgression during environmental change can weaken reproductive isolation. Nat. Clim. Chang. 10, 58–62 (2020).

Download citation