POPULATION GENOMIC TESTS OF MODELS OF ADAPTIVE RADIATION IN LAKE VICTORIA REGION CICHLID FISH
Article first published online: 1 SEP 2011
© 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.
Volume 65, Issue 12, pages 3381–3397, December 2011
How to Cite
Bezault, E., Mwaiko, S. and Seehausen, O. (2011), POPULATION GENOMIC TESTS OF MODELS OF ADAPTIVE RADIATION IN LAKE VICTORIA REGION CICHLID FISH. Evolution, 65: 3381–3397. doi: 10.1111/j.1558-5646.2011.01417.x
- Issue published online: 1 DEC 2011
- Article first published online: 1 SEP 2011
- Accepted manuscript online: 29 JUL 2011 02:10PM EST
- Received November 10, 2010, Accepted June 24, 2011, Data Archived: Dryad doi:10.5061/dryad.gv1t0
- gene flow;
- genetic diversity;
Adaptive radiation is usually thought to be associated with speciation, but the evolution of intraspecific polymorphisms without speciation is also possible. The radiation of cichlid fish in Lake Victoria (LV) is perhaps the most impressive example of a recent rapid adaptive radiation, with 600+ very young species. Key questions about its origin remain poorly characterized, such as the importance of speciation versus polymorphism, whether species persist on evolutionary time scales, and if speciation happens more commonly in small isolated or in large connected populations. We used 320 individuals from 105 putative species from Lakes Victoria, Edward, Kivu, Albert, Nabugabo and Saka, in a radiation-wide amplified fragment length polymorphism (AFLP) genome scan to address some of these questions. We demonstrate pervasive signatures of speciation supporting the classical model of adaptive radiation associated with speciation. A positive relationship between the age of lakes and the average genomic differentiation of their species, and a significant fraction of molecular variance explained by above-species level taxonomy suggest the persistence of species on evolutionary time scales, with radiation through sequential speciation rather than a single starburst. Finally the large gene diversity retained from colonization to individual species in every radiation suggests large effective population sizes and makes speciation in small geographical isolates unlikely.