Assistant Professor
Ph.D. (2006) Duke University


Research Interests -

  • A fundamental goal of evolutionary biology is to explain how populations become reproductively isolated species. Does speciation occur in allopatry or do populations diverge in the presence of some gene flow? What is the genetic basis of reproductive isolation? What are the evolutionary forces that create and maintain variation in speciation genes? Our research tackles these questions in a new model system: the Mimulus guttatus species complex, a group of closely related, ecologically diverse wildflowers that exhibit tremendous variation in reproductive isolation between populations and species. We use a range of approaches – from field and greenhouse experiments to genetic mapping and bioinformatics – to investigate the genetic mechanisms and evolutionary dynamics of speciation.

Grant Support -

  • "CAREER: Molecular Evolution and Genetics of Hybrid Sterility in Mimulus", NSF.


Research Areas:
Selected Publications:
  • Garner A. G., Kenney, A. M., Fishman, L., Sweigart, A. L. 2016. Genetic loci with parent of origin effects cause hybrid seed lethality between Mimulus species. New Phytologist 211: 319-331.
  • Kenney A. M., Sweigart, A. L. 2016. Reproductive isolation and introgression between sympatric Mimulus species. Molecular Ecology 25: 2499-2517.
  • Ahmed-Braimah, Y. H. and A. L. Sweigart. 2015. A single gene causes an interspecific difference in pigmentation in Drosophila. Genetics 200: 331-342.
  • Sweigart, A. L. and L. E. Flagel. 2015. Evidence of natural selection acting on a polymorphic hybrid incompatibility locus in Mimulus. Genetics 199: 543-554.
  • Brandvain, Y.*, A. M. Kenney*, L. Flagel, G. Coop†, and A. L. Sweigart†. 2014. Speciation and introgression between Mimulus nasutus and Mimulus guttatus. PLoS Genetics 10: e1004410.
  • Zuellig, M. P., A. M. Kenney, A. L. Sweigart. 2014. Evolutionary genetics of plant adaptation: insights from new model systems. Curr. Opin. Plant Biol. 18: 44-50.
  • Fishman, L., A. L. Sweigart, A. M. Kenney, S. Campbell. 2014. Major QTLs control divergence in critical photoperiod for flowering between selfing and outcrossing species of monkeyflower (Mimulus). New Phytologist 201: 1498-1507.
  • Sweigart, A. L. and J. H. Willis, 2012. Molecular evolution and genetics of postzygotic reproductive isolation in plants. F1000 Biology Reports 4:23.
  • Sweigart, A.L. 2010. Simple Y-autosomal incompatibilities cause hybrid male sterility in reciprocal crosses between Drosophila virilis and D. americana. Genetics 184: 779-787.
  • Sweigart, A.L. 2010. The genetics of postmating, prezygotic reproductive isolation between Drosophila virilis and D. americana. Genetics 184: 401-410.
  • Sweigart, A.L., N.H. Martin and J.H. Willis. 2008. Patterns of nucleotide variation and reproductive isolation between a Mimulus allotetraploid and its progenitor species. Molecular Ecology 17: 2089-2100.
  • Sweigart, A.L., A.R. Mason and J.H. Willis. 2007. Natural variation for a hybrid incompatibility between two species of Mimulus. Evolution 61: 141-151.
  • Sweigart, A.L., L. Fishman and J.H. Willis. 2006. A simple genetic incompatibility causes hybrid male sterility in Mimulus. Genetics 172: 2465-2479.
  • Sweigart, A.L. and J.H. Willis. 2003. Patterns of nucleotide diversity are affected by mating system and asymmetric introgression in two species of Mimulus. Evolution 57: 2490-2506.
  • Sweigart, A., K. Karoly, A. Jones and J.H. Willis. 1999. The distribution of individual inbreeding coefficients and pairwise relatedness in a population of Mimulus guttatus. Heredity 8: 625-632.
Personal Website: