CHROMOSOMAL INVERSIONS AND SPECIES DIFFERENCES: WHEN ARE GENES AFFECTING ADAPTIVE DIVERGENCE AND REPRODUCTIVE ISOLATION EXPECTED TO RESIDE WITHIN INVERSIONS?
Article first published online: 28 JUL 2009
© 2009 The Author(s). Journal compilation © 2009 The Society for the Study of Evolution
Volume 63, Issue 12, pages 3061–3075, December 2009
How to Cite
Feder, J. L. and Nosil, P. (2009), CHROMOSOMAL INVERSIONS AND SPECIES DIFFERENCES: WHEN ARE GENES AFFECTING ADAPTIVE DIVERGENCE AND REPRODUCTIVE ISOLATION EXPECTED TO RESIDE WITHIN INVERSIONS?. Evolution, 63: 3061–3075. doi: 10.1111/j.1558-5646.2009.00786.x
- Issue published online: 19 NOV 2009
- Article first published online: 28 JUL 2009
- Received March 17, 2009Accepted June 23, 2009
- fitness trade-offs;
- gene flow;
- genomic islands;
- local adaptation;
Many factors can promote speciation, and one which has received much attention is chromosomal inversions. A number of models propose that the recombination suppressing effects of inversions facilitate the maintenance of differences between interbreeding populations in genes affecting adaptive divergence and reproductive isolation. These models predict that such genes will disproportionately reside within inversions, rather than in collinear regions. This hypothesis has received some support, but exceptions exist. Additionally, the effects of known low levels of recombination within inversions on these models are uninvestigated. Here, simulations are used to compare the maintenance of genetic differences between populations following secondary contact and hybridization in different inversion models. We compare regions with no recombination within them to regions with low recombination and to collinear regions with free recombination. Our most general finding is that the low levels of recombination within an inversion often result in the loss of accentuated divergence in inverted regions compared to collinear ones. We conclude that inversions can facilitate the maintenance of species differences under some conditions, but that large or qualitative differences between inverted and collinear regions need not occur. We also find that strong selection facilitates maintenance of divergence in a manner analogous to inversions.