Divergence with gene flow across a speciation continuum of Heliconius butterflies

BMC Evolutionary Biology

Research Article

Brian A. Counterman¹  Riccardo Papa²  Heather M. Hines³  W. Owen McMillan⁴  Megan A. Supple⁵ 

[1] Department of Biological Sciences, Mississippi State University, 295 Lee Boulevard, 39762, Mississippi State, MS, USA;Department of Biology and Center for Applied Tropical Ecology and Conservation, University of Puerto Rico—Rio Piedras, 00931, San Juan, Puerto Rico;Department of Biology, Pennsylvania State University, 208 Mueller Laboratory, 16802, University Park, PA, USA;Smithsonian Tropical Research Institute, Panamá City, Panamá;Smithsonian Tropical Research Institute, Panamá City, Panamá;Biomathematics Program, North Carolina State University, 27695, Raleigh, NC, USA;Research School of Biology, The Australian National University, 134 Linnaeus Way, 2601, Canberra, ACT, Australia;

关键词: Speciation genomics;    Speciation continuum;    Genomic divergence;    Heliconius;   

DOI  :  10.1186/s12862-015-0486-y

 received in 2015-03-20, accepted in 2015-09-14,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundA key to understanding the origins of species is determining the evolutionary processes that drive the patterns of genomic divergence during speciation. New genomic technologies enable the study of high-resolution genomic patterns of divergence across natural speciation continua, where taxa pairs with different levels of reproductive isolation can be used as proxies for different stages of speciation. Empirical studies of these speciation continua can provide valuable insights into how genomes diverge during speciation.MethodsWe examine variation across a handful of genomic regions in parapatric and allopatric populations of Heliconius butterflies with varying levels of reproductive isolation. Genome sequences were mapped to 2.2-Mb of the H. erato genome, including 1-Mb across the red color pattern locus and multiple regions unlinked to color pattern variation.ResultsPhylogenetic analyses reveal a speciation continuum of pairs of hybridizing races and incipient species in the Heliconius erato clade. Comparisons of hybridizing pairs of divergently colored races and incipient species reveal that genomic divergence increases with ecological and reproductive isolation, not only across the locus responsible for adaptive variation in red wing coloration, but also at genomic regions unlinked to color pattern.DiscussionWe observe high levels of divergence between the incipient species H. erato and H. himera, suggesting that divergence may accumulate early in the speciation process. Comparisons of genomic divergence between the incipient species and allopatric races suggest that limited gene flow cannot account for the observed high levels of divergence between the incipient species.ConclusionsOur results provide a reconstruction of the speciation continuum across the H. erato clade and provide insights into the processes that drive genomic divergence during speciation, establishing the H. erato clade as a powerful framework for the study of speciation.

【 授权许可】

CC BY   
© Supple et al. 2015

【 图 表 】

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