We tend to think of the discovery of a new species as requiring a trip to a remote and exotic location. But our ability to use DNA to determine how closely populations are related has revealed an unexpected fact: lots of plants and animals that look indistinguishable to the human eye are actually quite distant from each other genetically, often far enough to merit a new species designation. In the latest example, researchers have found that a population of leopard frogs that make their home in the New York City area are probably a newly discovered species.

According to the press release accompanying the new paper, the leopard frogs in the region were noted as having a croak that was quite distinct from those of the two species that inhabit the northern and southern parts of the East Coast. (A researcher involved in the finding described the other species as having a "long snore" or a "rapid chuckle.") Speculation had focused on the possibility that the New York frogs were a hybrid of the two species, but molecular evidence shows that they are distant from both.

Although New York City has probably not been especially kind to the frogs—any appropriate habitat for them in Manhattan is probably long gone—they still survive in a number of areas nearby, including New Jersey, Staten Island, and the Bronx. The researchers suggest that their range is probably centered on Yankee Stadium. Given the molecular evidence, the team that found the species (which has members in New Jersey, Alabama, and California) are now going back to study it more closely so that they can give it a formal description.

Molecular Phylogenetics and Evolution, 2012. DOI: 10.1016/j.ympev.2012.01.021 (About DOIs).