The researchers studied cichlid fishes in two African lakes to understand how they rapidly evolved into different species. They found that in Lake Mweru, where different cichlid species mixed and hybridized, there was more genetic potential for adaptation. This led to multiple adaptive radiations, where the fishes evolved different shapes and behaviors to fit their environments. In contrast, in Lake Bangweulu where there was less mixing between species, there was no evidence of adaptive radiation. This suggests that hybridization between species can create genetic variation that helps species adapt and evolve quickly.