The coincidence of ecological opportunity with hybridization explains rapid adaptive radiation in Lake Mweru cichlid fishes

Meier, Joana I.; Stelkens, Rike B.; Joyce, Domino A.; Mwaiko, Salome; Phiri, Numel; Schliewen, Ulrich K.; Selz, Oliver M.; Wagner, Catherine E.; Katongo, Cyprian; Seehausen, Ole

Abstract

© 2019, The Author(s). The process of adaptive radiation wasclassically hypothesized to require isolation of a lineage from its source (no gene flow) and from related species (no competition). Alternatively, hybridization between species may generate genetic variation that facilitates adaptive radiation. Here we study haplochromine cichlid assemblages in two African Great Lakes to test these hypotheses. Greater biotic isolation (fewer lineages) predicts fewer constraints by competition and hence more ecological opportunity in Lake Bangweulu, whereas opportunity for hybridization predicts increased genetic potential in Lake Mweru. In Lake Bangweulu, we find no evidence for hybridizationbut also no adaptive radiation. We show that the Bangweulu lineages also colonized Lake Mweru, where they hybridized with Congolese lineages and then underwent multiple adaptive radiationsthat are strikingly complementary in ecology and morphology. Our data suggestthat the presence of several related lineages does not necessarily prevent adaptive radiation, although it constrains the trajectories of morphological diversification. It might instead facilitate adaptive radiation when hybridization generates genetic variation, without which radiation may start much later, progress more slowly or never occur.

Citation

Meier, J. I., Stelkens, R. B., Joyce, D. A., Mwaiko, S., Phiri, N., Schliewen, U. K., Selz, O. M., Wagner, C. E., Katongo, C., & Seehausen, O. (2019). The coincidence of ecological opportunity with hybridization explains rapid adaptive radiation in Lake Mweru cichlid fishes. Nature communications, 10(1), https://doi.org/10.1038/s41467-019-13278-z

• Journal Article Type: Article
• Acceptance Date: Oct 22, 2019
• Online Publication Date: Dec 3, 2019
• Publication Date: 2019-12
• Deposit Date: Dec 3, 2019
• Publicly Available Date: Dec 4, 2019
• Journal: Nature Communications
• Electronic ISSN: 2041-1723
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 1
• DOI: https://doi.org/10.1038/s41467-019-13278-z
• Keywords: Adaptive radiation; Evolutionary ecology; Evolutionary genetics; Ichthyology
• Public URL: https://hull-repository.worktribe.com/output/3279096
• Publisher URL: https://www.nature.com/articles/s41467-019-13278-z
• Additional Information: Received: 28 April 2019; Accepted: 22 October 2019; First Online: 3 December 2019; : The authors declare no competing interests.
• Contract Date: Dec 4, 2019