Thursday, July 28, 2016

Cry Wolf, Not Wolves

An analysis of the entire genomes of wolves and coyotes (Canis latrans) has come to an unexpected conclusion:  there is a single species of North American wolf.  Previously, some biologists, including at the United States Fish and Wildlife Service ("FWS"), which is responsible for implementing the Endangered Species Act ("ESA"), proposed the existence of three species:  the Gray Wolf (Canis lupus), Red Wolf (Canis rufus), and Eastern (or Great Lakes region) Wolf (Canis lycaon).  In their article, Whole-genome sequence analysis shows that two endemic species of North American wolf are admixtures of the coyote and gray wolf, published on July 27, 2016, in Science Advances, Bridgett M. von Holdt and her colleagues instead conclude that:
Consistent with the above results, Great Lakes region wolves and red wolves are admixed populations composed of various proportions of gray wolf and coyote ancestry. The red wolf may have captured genomic elements that were unique to gray wolves and coyotes of the American South. In contrast, the Great Lakes region wolves largely sample lineages of gray wolves and coyotes that have descendants in the extant population, which may include a distinct gray wolf ecotype. We find little evidence of distinct genomic elements in either red or Great Lakes region wolves that would support separate evolutionary legacies.  (References omitted.)
This study has important implications for how the FWS protects various admixed populations of wild canids under the ESA.  Coywolves and woyotes warrant protection despite their admixed genomes, in part because, as keystone predators, they help regulate vital trophic cascades in the ecosystems they inhabit.  However, their newly-uncertain taxonomic status may undermine strong legal protections they would otherwise receive as "species".  Two lessons to draw from these genomic revelations are that (1) the ESA and its interpretation need to continue grappling with rapid progress in genetics and (2) the biologically-wobbly concept of "species" gets riper for replacement with each passing day.

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