In one corridor in the Hall of North American Mammals, two wolves run through the midnight snow while two coyotes howl in the Yosemite sun just a few feet away. Both belong to the genus Canis, and advances in genetic research are revealing that the adjacency of the dioramas is appropriate for another reason.
Through sequencing the mitochondrial DNA of 686 coyotes, a team of scientists recently found that many coyotes in the eastern United States are actually part wolf.
By tracing which genes in a given DNA sample belong to each wild canine, researchers were finally able to understand why northeastern coyotes are larger than those in the West. Nearly a century ago, coyotes mated with wolves in the Great Lakes region and produced fertile offspring. These hybrids, larger than coyotes but smaller than wolves, then migrated east through Canada and could hunt deer and colonize more effectively than a second front of coyotes—all non-wolf—that arrived east via Ohio.
“In the 1950s, researchers knew eastern coyotes looked different and thought they were hybrids, but there was no way to evaluate that by looking at skull measurements,” says Roland Kays, a professor at North Carolina State University who conducted the research and advised on the development of the hall’s new wall panels. “DNA sequencing allows us to show they were right.” (It also shows that eastern coyotes are part domestic dog, too.)
DNA sequencing continues to challenges the notion of “species” as distinct units in nature, complicating the understanding of what a species really is. “The idea is a human-made concept that doesn’t necessarily fit the variation in nature,” says Kays. “The lines are not always black and white.”
Given how new technologies have enriched—and at times overturned—the understanding of these scenes since 1942, imagine what stories the dioramas will be telling 70 years from now.
A version of this story appeared in the Fall 2012 issue of Rotunda, the Member magazine.