Real-Time Evolution

Researchers find evidence that a variety of African electric fish are approaching speciation.

In what seems like a freshwater version of playing hard to get, a peculiar species of electric fish in Gabon's Ivindo River Basin may provide a rare snapshot of the evolutionary divergence of one species into two.

Researchers from Cornell University found that genetically identical fish are sending out two different electric signals, and certain male members of the species ignore some signals emitted by females, responding only to pulses similar to their own. The strict selectivity for specific signals observed in these electric fish may eventually result in different mating groups, leading researchers to surmise that the fish could be on the verge of speciation.

Evolution is a historical, inferential science—you can't really see it happening before your eyes, said Matt Arnegard, a neurobiology and behavior postdoc at Cornell and lead author of the study, which appears in the June issue of The Journal of Experimental Biology. We think maybe this is an example where we're really close to seeing it happen before our eyes.