We often hear that science has proved that race does not exist. But I alway ask, Don’t the same arguments about blurry boundaries and the like also apply to the proposition that species does not exist? Then I cite confusing cases regarding species that have big money implications under the Endangered Species Act. Are dogs, coyotes, and wolves one species or separate species? What about red wolves?

In the NYT, Carl Zimmer brings us up to date on the latest findings regarding my go-to example:

DNA Study Reveals the One and Only Wolf Species in North America

Carl Zimmer

MATTER JULY 27, 2016

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 United States 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 Endangered Species Act address threatened animals that are hybrids? …

Those efforts were possible because of the Endangered Species Act, established in 1973. The law led to a recovery program for a species known as the red wolf, or Canis rufus, believed to have originally lived in the Southeast. The last red wolves were removed from the wild in 1980, and captive-bred animals were released into the wild beginning in 1987.

The gray wolf, or Canis lupus, once ranged from the Rockies to New England. In 1978, the Fish and Wildlife Service 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 Fish and Wildlife Service 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.

The new study revealed that coyotes and North American wolves shared a remarkably recent common ancestor. Scientists had previously estimated their ancestor lived a million years ago, but the new study put the figure at just 50,000 years ago.

“I could not have put money on it being so recent,” Dr. vonHoldt said.

That ancestor gave rise to two species — the predecessor of today’s gray wolves and that of today’s coyotes — somewhere in Eurasia. Dr. vonHoldt said that the two species then migrated into North America.

… Some wolf experts were startled by the finding and said it would require further support.

Linda Y. Rutledge, an expert on Eastern wolves, questioned whether the new study was sufficient to reject them as a separate species. …

Yet the Endangered Species Act offers no guidance about what to do with hybrid animals.