From Cornell University (USA):
Evolution in action?
African fish could be providing rare example of forming two separate species, Cornell scientists speculate
By Sara Ball
However, they now have found a case where two types of electric signals come from fish that have the same DNA.
The researchers’ conclusion: The fish appear to be on the verge of forming two separate species.
“We think we are seeing evolution in action,” said Matt Arnegard, a neurobiology postdoctoral researcher in the laboratory of Carl Hopkins, Cornell professor of neurobiology and behavior, who has been recording electric fish in Gabon since the 1970s.
The research, published in the June issue of the Journal of Experimental Biology, describes how some of these fish violate an otherwise regular pattern of mating behavior, and so could be living examples of a species of fish diverging into separate species.
The electric fish — known as mormyrids — emit weak electric fields from a batterylike organ in their tails to sense their surroundings and communicate with other fish.