DNA Study Reveals Only One Wolf Species in North America

The first large study of North American wolf genomes has found that there is only one species on the continent: the gray wolf. Two other purported species, the Eastern wolf and the red wolf, are mixes of gray wolf and coyote DNA, the scientists behind the study concluded. 

The finding, announced Wednesday, highlights the shortcomings of laws intended to protect endangered species, as such laws lag far behind scientific research into the evolution of species. The gray wolf and red wolf were listed as endangered in the lower 48 states under the Endangered Species Act in the 1970s and remain protected today, to the periodic consternation of ranchers and agricultural interests. 

In 2013, the U.S. Fish and Wildlife Service recognized the Eastern wolf as a separate species, which led officials to recommend delisting the gray wolf. Conservationists won a lawsuit that forced the agency to abandon the plan. 

The new finding sharpens a scientific question at the heart of that debate: How should the ESA address threatened animals that are hybrids? 

"What's very exciting about this paper is that it's using extremely powerful tools to address longstanding, challenging questions in conservation," said Ryan Kovach, a research wildlife biologist at the United States Geological Survey who was not involved in the new study. 

The gray wolf, or Canis lupus, once ranged from the Rockies to New England. In 1978, the FWS declared it to be threatened in the lower 48 states. 

In 2000, some scientists began to argue that the eastern population of gray wolves was in fact a separate species, which they called Canis lycaon. The FWS recognized that species in 2013, and officials argued that the gray wolf, now deemed to be limited to the Western United States, was doing well enough to be taken off the list. 

The new analysis, published in the journal Science Advances, paints a profoundly different portrait of the American wolf. 

Bridgett M. vonHoldt of Princeton University and her colleagues sequenced the genomes of 12 gray wolves, six Eastern wolves, three red wolves and three coyotes, as well as the genomes of dogs and wolves from Asia. 

Dr. vonHoldt and her colleagues found no evidence that red wolves or Eastern wolves belonged to distinct lineages of their own. Instead, they seem to be populations of gray wolves, sharing many of the same genes. 

What really sets Eastern wolves and red wolves apart, the researchers found, is a large amount of coyote DNA in their genomes. 

To read the research article, go to http://advances.sciencemag.org/content/2/7/e1501714.full.