One of the reasons I’ve learned to stay away from debates about “what is a species” is that practical species definitions (i.e., something we can use to classify critters) do a lousy job of describing the process of speciation, while conceptually sound species definitions (ones that describe the speciation process) are usually miserable when you actually try to classify organisms. Why? Because delineating species implies (and requires) sharp biological breaks that might not exist. Case in point, the Eastern coyote:
Two separate teams of researchers studying the genes of coyotes in the Northeast reported evidence that these animals that have for decades upon decades been thought of as coyotes are in fact coyote-wolf hybrids….
Both teams found that the animals carry wolf and coyote DNA. The paper by Dr. Kays and his colleagues was published in Biology Letters; the paper by Dr. Way and his colleagues was published in Northeastern Naturalist.
Based on the wolf DNA found in the Eastern coyotes, Dr. Kays and colleagues hypothesize in their paper that Western coyotes dispersing eastward north of the Great Lakes across Canada during the last century mated with wolves along the way, bringing that wolf DNA along with them to the Northeast.
The findings may explain why coyotes in the East are generally larger than their Western counterparts — that is, more wolflike in size — and why they are so much more varied in coat color, as might be expected from a creature with a more diverse genome. It may also explain why Eastern coyotes appear to be more adept as deer hunters than their Western forebears, which tend toward smaller prey, like voles and rabbits.
What the finding does not settle is how to define exactly what these animals are, or for that matter, what to call them. Dr. Way favors the term “coywolf” to denote the animals’ hybrid heritage. He said because these animals are part wolf — species that enjoy protected status — they deserve some benefits not available to coyotes, which are typically freely hunted.
Dr. Kays, however, says that he is not a fan of the name, in part because the animals are “mostly coyote and a little bit of wolf,” but also because the Eastern coyote may be less a finished product deserving of a name and more an evolutionary work in progress….
One major complication is that all the species in the genus Canis, to which the coyote belongs, can successfully interbreed. In other words, coyotes (or Canis latrans, meaning “barking dog”) and domestic dogs (Canis familiaris) and every kind of wolf, from the red wolf to the Eastern wolf to the gray wolf (Canis lupus), can mate and produce perfectly healthy pups. No wonder, then, that interactions among these species have led to a genetic mess that researchers sometimes refer to as “Canis soupus.”
I do think coyotes are amazing creatures, even if they are Canis soupus.