What shapes the continuum of reproductive isolation? Lessons from Heliconius butterflies
Proceedings of the Royal Society B: Biological Sciences
Royal Society of London
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Mérot, C., Salazar, C., Merrill, R., Jiggins, C. D., & Joron, M. (2017). What shapes the continuum of reproductive isolation? Lessons from Heliconius butterflies. Proceedings of the Royal Society B: Biological Sciences, 284 (1856)https://doi.org/10.1098/rspb.2017.0335
The process by which species evolve can be illuminated by investigating barriers that limit gene flow between taxa. Recent radiations, such as Heliconius butterflies, offer the opportunity to compare isolation between pairs of taxa at different stages of ecological, geographical, and phylogenetic divergence. Here, we report a comparative analysis of existing and novel data in order to quantify the strength and direction of isolating barriers within a well-studied clade of Heliconius Our results highlight that increased divergence is associated with the accumulation of stronger and more numerous barriers to gene flow. Wing pattern is both under natural selection for Müllerian mimicry and involved in mate choice, and therefore underlies several isolating barriers. However, pairs which share a similar wing pattern also display strong reproductive isolation mediated by traits other than wing pattern. This suggests that, while wing pattern is a key factor for early stages of divergence, it may become facultative at later stages of divergence. Additional factors including habitat partitioning, hybrid sterility, and chemically mediated mate choice are associated with complete speciation. Therefore, although most previous work has emphasized the role of wing pattern, our comparative results highlight that speciation is a multi-dimensional process, whose completion is stabilized by many factors.
speciation, reproductive barriers, hybrid sterility, mate choice, Lepidoptera, magic trait
This work was supported by ERC Starting Grant Stg-243179 (MimEvol) and French Research Agency grant ANR-12-JSV7-0005 (HybEvol) to M.J. C.S. was funded by the Universidad del Rosario FIUR grant QDN-DG001 and COLCIENCIAS (Grant FP44842-5-2017). R.M.M. was funded by a Research Fellowship at King's College, Cambridge, UK. R.M.M. and C.D.J. were funded by an ERC grant (Speciation Genetics 339873).
External DOI: https://doi.org/10.1098/rspb.2017.0335
This record's URL: https://www.repository.cam.ac.uk/handle/1810/266427