STRONG ASYMMETRY IN THE RELATIVE STRENGTHS OF PREZYGOTIC AND POSTZYGOTIC BARRIERS BETWEEN TWO DAMSELFLY SISTER SPECIES
Article first published online: 20 NOV 2011
© 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.
Volume 66, Issue 3, pages 690–707, March 2012
How to Cite
Sánchez-Guillén, R. A., Wellenreuther, M. and Cordero Rivera, A. (2012), STRONG ASYMMETRY IN THE RELATIVE STRENGTHS OF PREZYGOTIC AND POSTZYGOTIC BARRIERS BETWEEN TWO DAMSELFLY SISTER SPECIES. Evolution, 66: 690–707. doi: 10.1111/j.1558-5646.2011.01469.x
- Issue published online: 1 MAR 2012
- Article first published online: 20 NOV 2011
- Accepted manuscript online: 23 SEP 2011 06:48AM EST
- Received November 21, 2010, Accepted September 5, 2011, Data Archived: Dryad: doi:10.5061/dryad.d34t730j
Vol. 67, Issue 5, 1538, Article first published online: 12 MAR 2013
- Asymmetric reproductive isolation;
- Darwin's corollary;
- postzygotic isolation;
- prezygotic isolation;
One of the longest debates in biology has been over the relative importance of different isolating barriers in speciation. However, for most species, there are few data evaluating their relative contributions and we can only speculate on the general roles of pre- and postzygotic isolation. Here, we quantify the absolute and cumulative contribution of 19 potential reproductive barriers between two sympatric damselfly sister species, Ischnura elegans and I. graellsii, including both premating (habitat, temporal, sexual and mechanical isolation) and postmating barriers (prezygotic: sperm insemination success and removal rate, oviposition success, fertility, fecundity; postzygotic: hybrid viability, hybrid sterility and hybrid breakdown). In sympatry, total reproductive isolation between I. elegans females and I. graellsii males was 95.2%, owing mostly to a premating mechanical incompatibility (93.4%), whereas other barriers were of little importance. Isolation between I. graellsii females and I. elegans males was also nearly complete (95.8%), which was caused by the cumulative action of multiple prezygotic (n= 4, 75.4%) and postzygotic postmating barriers (n= 5, 7.4%). Our results suggest that premating barriers are key factors in preventing gene flow between species, and that the relative strengths of premating barriers is highly asymmetrical between the reciprocal crosses.