Large Amazonian rivers impede dispersal for many species, but lowland river networks frequently rearrange, thereby altering the location and effectiveness of river barriers through time. These rearrangements may promote biotic diversification by facilitating episodic allopatry and secondary contact among populations. We sequenced genome-wide markers to evaluate the histories of divergence and introgression in six Amazonian avian species complexes. We first tested the assumption that rivers are barriers for these taxa and found that even relatively small rivers facilitate divergence. We then tested whether species diverged with gene flow and recovered reticulate histories for all species, including one potential case of hybrid speciation. Our results support the hypothesis that river rearrangements promote speciation and reveal that many rainforest taxa are micro-endemic, unrecognized, and thus threatened with imminent extinction. We propose that Amazonian hyper-diversity originates partly from fine-scale barrier displacement processes-including river dynamics-which allow small populations to differentiate and disperse into secondary contact.
River network rearrangements promote speciation in lowland Amazonian birds
Publication Details
SCIENCE ADVANCES, v 8(14), eabn1099
Publisher
AMER ASSOC ADVANCEMENT SCIENCE; WASHINGTON
Grant note
This work was funded, in part, by Richard Gilder Graduate Research Fellowship (to L.J.M.), The Linda Gormezano Memorial Fund research grant (to L.J.M.), The Society for Systematic Biologists graduate student research grant (to L.J.M.), and NSF/NASA Dimensions US-Biota-Sao Paulo grant 1241066 (to J.C.).
Resource Type
Journal article
Language
English
Academic Unit
Drexel University
Web of Science ID
WOS:000800335500018
Scopus ID
2-s2.0-85127873059
Other Identifier
991021861215104721
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