I study the evolutionary response of populations to environmental change. I am particularly interested in understanding how genetic exchange between populations and species alters the rates and mechanisms of adaptation when populations are facing environmental stress. For this, I mainly use the unicellular microbe Baker's yeast (Saccharomyces spp.) and a combination of experimental evolution, sequencing and phenomics. Saccharomyces is one of the few model microbes that can reproduce sexually, which makes it a great system to study hybridization.

Some of my current projects are:

1. Does hybridization facilitate the colonization of novel environments?

2. Can hybridization contribute to evolutionary rescue?

3. Is there an optimal outcrossing distance that maximizes hybrid fitness?

4. What is the genetic architecture of hybrid fitness under environmental stress?

5. What is the evolutionary significance of aneuploidy, and how does it affect hybrid fitness?

6. Hybridization and pathogenesis: What is the significance of parasite hybridization for public health?

Other projects I am involved in look at local adaptation in natural yeast populations, the genetic basis of heterosis in yeast, and (since my background is fishy) an exciting new adaptive radiation of African cichlid fish!

If you are interested in any of the above or related questions, please drop me an email. I have some open positions (PhD and Postdoc) that I am looking to fill soon!


1. Bernardes J, RB Stelkens, D Greig, Heterosis in hybrids within and between yeast species, Journal of Evolutionary Biology, 2017, 30 (3): 538–548 doi: 10.1111/jeb.13023

2. Stelkens RB, D Greig, Fungal evolution: On the origin of yeast species, NATURE Microbiology 2016, 1 (1): 15017, doi: 10.1038/nmicrobiol2015.17

3. Boynton P, RB Stelkens, V Kowallik, D Greig, Measuring microbial fitness in a field reciprocal transplant experiment, Molecular Ecology Resources, 2016, doi: 10.1111/1755-0998.12562

4. Stelkens RB, EL Miller, D Greig, Asynchronous spore germination in isogenic, natural isolates of Saccharomyces paradoxus, FEMS Yeast Research, 2016, 16 (3) doi: 10.1093/femsyr/fow012

5. Stelkens RB, K King, J Webster, D Smith, M Brockhurst, Hybridization in parasites: Consequences for adaptive evolution, pathogenesis, and public health in a changing world, PLOS Pathogens, 2015, 11(9): e1005098

6. Stelkens RB, C. Schmid, O Seehausen, Hybrid breakdown in cichlid fish, PLOS ONE, 2015, 10(5): e0127207

7. Stelkens RB, M Brockhurst, G Hurst, E Miller, D Greig, The effect of hybrid transgression on environmental tolerance in experimental yeast crosses. Journal of Evolutionary Biology, 2014, 27(11): 2507-2519

8. Stelkens RB, M Brockhurst, G Hurst, D Greig, Hybridization facilitates evolutionary rescue, Evolutionary Applications, 2014, 7(10): 1209-1217

9. Stelkens RB, M Pompini, C Wedekind, Testing the effects of genetic crossing distance on embryo survival within a metapopulation of brown trout (Salmo trutta). Conservation Genetics, 2014, 15: 375-386

10. Stelkens RB, ES Clark, C Wedekind, Parental influences on pathogen resistance in brown trout embryos and effects of outcrossing within a river network, PLOS ONE, 2013, 8: e57832

11. Stelkens RB, M Pompini, C Wedekind, Testing for local adaptation in brown trout using reciprocal transplants. BMC Evolutionary Biology, 2012, 12: 247

12. Abbott R, D Albach, S Ansell, JW Arntzen, SJE Baird, N Bierne et al. (incl. RB Stelkens), Hybridization and speciation. Journal of Evolutionary Biology, 2012, 26: 229-246

13. Stelkens RB, G Jaffuel, M Escher, C Wedekind, Genetic and phenotypic population divergence on a microgeographic scale in brown trout. Molecular Ecology, 2012, 21:2896-2915

14. Stelkens RB, C Wedekind, Environmental sex reversal, Trojan sex genes, and sex ratio adjustment: conditions and population consequences. Molecular Ecology, 2010, 19: 627–646

15. Wedekind C, RB Stelkens, Tackling the diversity of sex determination. Biology Letters, 2010, 6: 7-9

16. Stelkens RB, KA Young, O Seehausen, The accumulation of reproductive incompatibilities in African cichlid fish. Evolution, 2010, 64:617-633

17. Stelkens RB, C Schmid, O Selz, O Seehausen, Phenotypic novelty in experimental hybrids is predicted by the genetic distance between species of cichlid fish. BMC Evolutionary Biology, 2009, 9:283, doi: 10.1186/1471-2148-9-283

18. Stelkens RB, O Seehausen, Genetic distance between species predicts novel trait expression in their hybrids. Evolution, 2009, 63:884-897

19. Stelkens RB, O Seehausen, Phenotypic divergence but not genetic distance predicts assortative mating among species of a new cichlid fish radiation. Journal of Evolutionary Biology, 2009, 22:1679-1694

20. Stelkens RB, MER Pierotti, DA Joyce, AM Smith, I van der Sluijs, O Seehausen, Disruptive sexual selection on male nuptial coloration in an experimental hybrid population of cichlid fish. Philosophical Transactions of the Royal Society B-Biological Sciences, 2008, 363:2861-2870

21. van der Sluijs I, TJM Van Dooren, KD Hofker, JJM van Alphen, RB Stelkens, O Seehausen, Female mating preference functions predict sexual selection against hybrids between sibling species of cichlid fish. Philosophical Transactions of the Royal Society B-Biological Sciences, 2008, 363:2871-2877