Researchers from several institutions found in a molecular analysis that spinner dolphins and striped dolphins helped create the clymene dolphin. Questions about the clymene dolphin’s origins have been unanswered for many years, so the team from the Wildlife Conservation Society, the American Museum of Natural History’s Sackler Institute for Comparative Genomics, the University of Lisbon, and other contributing groups decided to solve this riddle once and for all.

Taxonomists originally considered the clymene dolphin a subspecies of the spinner dolphin,but in 1981, scientists began to recognize it as a distinct species. However, the latest study sought to clarify its origins, finding that it was a result of natural hybridization.

“Our study represents the first such documented instance of a marine mammal species originating through the hybridization of two other species,”stated Ana R. Amaral, lead author of the study and research associate at the American Museum of Natural History. “This also provides us with an excellent opportunity to better understand the mechanisms of evolution.”

Clymene dolphins have a similar physical appearance to their relatives, and the latest genetic results show why. Natural hybridization is a fairly common process in the evolutionary history of plants, fishes and birds, but is considered rare among mammals.