Jump in communication skills led to species explosion among electric fishes

The Mormyridae, a family of African fishes that communicate by means of weak electic discharges, has more than 200 species. Given its diversity a Washington University in St. Louis biologist wondered whether changes in electric communication might have influenced rates of speciation. His work showed that the fishes evolved a complex signal-processing brain before a burst of speciation, that signal variation was higher among fishes with that brain, and that these fishes could distinguish among subtly different discharges, whereas others could not.Together it adds up to a strong case for brain evolution triggering increased diversification.