Colonizations and demographic history of cichlid fishes in crater lakes in Nicaragua
Abstract There are several crater lakes in Nicaragua that each houses a small adaptive radiation of up to six endemic species of Midas cichlid fishes (see, e.g., Barluenga et al. 2006 Nature, Elmer et al 2012 Evolution). These crater lakes are completely isolated, there are no rivers that connect them or that flow out of these lakes. These species flocks have become text book examples for extremely fast sympatric speciation and the repeated evolution of similar phenotypes (reviewed in Elmer and Meyer 2011). Many, but possibly not all, of these radiations can be traced back to a single colonization event from which all fish in these crater lakes (some of them are less than 2000 years old and some as old as 20,000 years) are descended.
It is not clear how these fish colonized the crater lakes - if they were brought there by birds, humans or through cataclysmic events such as so-called “fish rains”. To be able to better understand the patters and processes of speciation and the formation of the crater lake ecosystems it would be important to find out how many, when and how all fishes, not only Midas cichlids, but also other cichlids and other families of fishes entered theses lakes. We are looking for a student (who ideally speaks Spanish and likes field work as much as populations genomics) who would like to tackle this problem by sampling all kinds of organisms from the crater lakes of Nicaragua, who collects genome wide data (using Illumina RADseq analyses) to collect SNP data for population genomics analysis. Based on these kinds of data, combined with simulation analyses and coalescence analysis we hope to reconstruct the demographic and phylogenetic history of species living in these crater lakes.
Keywords sympatric speciation, evolution, population genomics, ecological specialization
Main advisor Axel Meyer, University of Konstanz
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Kautt, A.F., Elmer, K.R. and A. Meyer. 2012. Genomic signatures of divergent selection and speciation patterns in a ‘natural experiment’, the young parallel radiations of Nicaraguan crater lake cichlid fishes. Molecular Ecology 21: 4770–4786.
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Barluenga, M. and A. Meyer. 2010. Phylogeography, colonization and population history of the Midas cichlid species complex (Amphilophus spp.) in the Nicaraguan crater lakes. BMC Evolutionary Biology 10: 326.
Barluenga, M. and A. Meyer. 2010. Phylogeography, colonization and population history of the Midas cichlid species complex (Amphilophus spp.) in the Nicaraguan crater lakes. BMC Evolutionary Biology 10: 326.