GENOMIC REGIONS WITH A HISTORY OF DIVERGENT SELECTION AFFECT FITNESS OF HYBRIDS BETWEEN TWO BUTTERFLY SPECIES
Article first published online: 23 FEB 2012
© 2012 The Author(s).
Volume 66, Issue 7, pages 2167–2181, July 2012
How to Cite
Gompert, Z., Lucas, L. K., Nice, C. C., Fordyce, J. A., Forister, M. L. and Buerkle, C. A. (2012), GENOMIC REGIONS WITH A HISTORY OF DIVERGENT SELECTION AFFECT FITNESS OF HYBRIDS BETWEEN TWO BUTTERFLY SPECIES. Evolution, 66: 2167–2181. doi: 10.1111/j.1558-5646.2012.01587.x
- Issue published online: 3 JUL 2012
- Article first published online: 23 FEB 2012
- Accepted manuscript online: 1 FEB 2012 02:45PM EST
- Received August 11, 2011, Accepted January 13, 2012, Data Archived: Dryad: doi:10.5061/dryad.f0b2f083
- Divergent selection;
- population genomics;
Speciation is the process by which reproductively isolated lineages arise, and is one of the fundamental means by which the diversity of life increases. Whereas numerous studies have documented an association between ecological divergence and reproductive isolation, relatively little is known about the role of natural selection in genome divergence during the process of speciation. Here, we use genome-wide DNA sequences and Bayesian models to test the hypothesis that loci under divergent selection between two butterfly species (Lycaeides idas and L. melissa) also affect fitness in an admixed population. Locus-specific measures of genetic differentiation between L. idas and L. melissa and genomic introgression in hybrids varied across the genome. The most differentiated genetic regions were characterized by elevated L. idas ancestry in the admixed population, which occurs in L. idas-like habitat, consistent with the hypothesis that local adaptation contributes to speciation. Moreover, locus-specific measures of genetic differentiation (a metric of divergent selection) were positively associated with extreme genomic introgression (a metric of hybrid fitness). Interestingly, concordance of differentiation and introgression was only partial. We discuss multiple, complementary explanations for this partial concordance.