Fig. 6.

From cichlid phenotypes to genotypes to functional validation. Over the last decade, cichlid fishes have become a prime model to study genotype–phenotype relationships. The ability to collect samples from the field and to conduct hybrid crosses (even between species) makes it possible to identify the genetic bases of traits using genome-wide association (GWA) mapping and qualitative/quantitative trait loci (QTL) mapping, respectively. In combination with other methodologies (especially approaches that include functional validation) candidate genes and mutations can be identified and functionally validated as genes underlying phenotypic variation. Note that for simplicity a simple (qualitative) trait was used in this figure; both analyses can be and are also performed with complex (quantitative) traits