Figure 1

Morphological disparity through time plots and morphological diversity indices (MDI) for brain weight (a) and the size of six major brain structures: b; olfactory bulbs, c; telencephalon, d; optic tecta, e; cerebellum, f; dorsal medulla and g; hypothalamus. The bold black line shows the actual morphological disparity of the trait while the broken line shows the median disparity when trait evolution is modeled on the phylogeny following Brownian motion. Time is expressed as millions of years from the present, based on estimated dates for the Tanganyikan cichlid radiation (see Methods).