Ford, AGP;
Dasmahapatra, KK;
Rüber, L;
Gharbi, K;
Cezard, T;
Day, JJ;
(2015)
High levels of interspecific gene flow in an endemic cichlid fish adaptive radiation from an extreme lake environment.
Molecular Ecology
, 24
(13)
pp. 3421-3440.
10.1111/mec.13247.
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Abstract
Studying recent adaptive radiations in isolated insular systems avoids complicating causal events and thus may offer clearer insight into mechanisms generating biological diversity. Here, we investigate evolutionary relationships and genomic differentiation within the recent radiation of Alcolapia cichlid fish that exhibit extensive phenotypic diversification, and which are confined to the extreme soda lakes Magadi and Natron in East Africa. We generated an extensive RAD data set of 96 individuals from multiple sampling sites and found evidence for genetic admixture between species within Lake Natron, with the highest levels of admixture between sympatric populations of the most recently diverged species. Despite considerable environmental separation, populations within Lake Natron do not exhibit isolation by distance, indicating panmixia within the lake, although individuals within lineages clustered by population in phylogenomic analysis. Our results indicate exceptionally low genetic differentiation across the radiation despite considerable phenotypic trophic variation, supporting previous findings from smaller data sets; however, with the increased power of densely sampled SNPs, we identify genomic peaks of differentiation (FST outliers) between Alcolapia species. While evidence of ongoing gene flow and interspecies hybridization in certain populations suggests that Alcolapia species are incompletely reproductively isolated, the identification of outlier SNPs under diversifying selection indicates the radiation is undergoing adaptive divergence.
| Type: | Article |
|---|---|
| Title: | High levels of interspecific gene flow in an endemic cichlid fish adaptive radiation from an extreme lake environment |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1111/mec.13247 |
| Publisher version: | http://dx.doi.org/10.1111/mec.13247 |
| Language: | English |
| Additional information: | © 2015 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
| Keywords: | adaptive radiation; admixture; Alcolapia; cichlid; hybridization; Lake Magadi;Lake Natron; Oreochromis ; RAD |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences > Genetics, Evolution and Environment |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1468999 |
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