It has been nearly a year since the paradigm-shattering study on the wolf and coyote genomes was released. (vonHolt 2011). The study examined 48,000 SNP’s (single-nucleotide polymorphism) in the genomes of these species and compared them to each other. In this way, the researchers were able to see which animals were most closely related to each other.
The study was the most in-depth analysis of a wild species’ genome that had ever been performed, and it revealed that several sacred cows in wolf taxonomy are not what they have been proposed to be.
The same was found for the red wolf of the southeastern US.
Most of these studies were designed to counter Robert Wayne’s study that revealed that all red wolves actually had coyote mtDNA. He initially contended that they were hybrids between wolves and coyotes, but red wolves were still worthy of conservation because a large number of wolves had coyote mtDNA sequeneces. Wayne also found at least one red wolf with wolf mtDNA sequence, which really raised a red flag. Although most red wolves were found to have coyote mtDNA, finding one with wolf mtDNA was really indicative of these animals being of hybrid origin.
Of course, this drove some people really crazy. Ron Nowak, a comparative anatomist who worked for the US Fish and Wildlife Service, tried several times to connect the red wolf to any number of prehistoric wolf-like canids that existed in North America, as well as claiming that the reason why these animals appeared to have coyote mtDNA is because they, as native North American Canis, would be more closely related to the coyote. It would not necessarily be indicative of hybridization.
Mitochondrial DNA is inherited only maternally, and we do know that when wolves and coyotes mate in the wild, the hybrid is almost always a male wolf mating with a female coyote.
So we have this problem of certain animals that are called wolves that have coyote mtDNA.
And there were three potential hypotheses:
- These wolves represent an ancient species that evolved from the same ancestor as the coyote.
- These wolves are the same species as other wolves. They just have coyote mtDNA from a coyote that entered the gene pool in recent times.
- These wolves are a unique species that resulted from an ancient hybridization between wolves and coyotes.
I generally came to accept a sort of hybrid between 2 and 3. I thought that red wolves and Eastern wolves were the result of an old introgression of coyote genes into the wolf population. When the first wolves came across the Bering Land Bridge, they likely didn’t come in large numbers and as they came down into the middle latitudes of North America, the only available mates would have been coyotes. They mated with female coyotes and carried coyote mtDNA into Eastern North America.
However, the vonHolt SNP study changed all of this.
It essentially rendered all previous hypotheses and findings moot.
What this study found was the the wolves with coyote mtDNA, the red wolves and those of the Great Lakes and Eastern Canada, had SNP’s in common with Canis lupus and Canis latrans. Eastern coyotes also had wolf SNP’s.
And what’s more, all the hybridizations, except the one involving the Western Great Lakes wolves, happened after colonization. The Western Great Lakes hybridization happened between 600 and 900 years ago, but these wolves are only 15 percent coyote on average. Thus, after that initial cross, they have been breeding back into wolves.
Red wolves were found to be almost entirely coyote, averaging 76 percent coyote and 24 percent wolf. Algonquin Park wolves, which have been much ballyhooed in the Canadian wildlife literature, are pretty close to 50/50 wolf and coyote. They averaged 58 percent wolf and 42 percent coyote.
If these animals had been an ancient unique species, it would have come out in this analysis. Instead, this analysis found something more interesting. Wolves and coyotes are distinct species, but the edge between them is blurred a bit. Wolves and coyotes do exchange genes under certain circumstances. In this way, there is a sort of species complex between them.
But what about discoveries of pre-Columbian wolves with coyote mtDNA?
Rutledge found coyote mtDNA sequences in wolf-like canids that were living in Quebec 400-500 years ago.
But these hybrids were around centuries after the wolves of the Great Lakes received their coyote introgression. Perhaps these pre-Columbian wolves with coyote mtDNA were initially more widespread. The Great Lakes and Quebec are actually linked as a waterway and the terrain makes it very easy for animals to move from one side to the other.
The Great Lakes and into the St. Lawrence is a major pathway for Carnivorans. This is the path that coyotes used to enter the northeastern US all the way down to Virginia.
So these two species have interbred at different times.
The Eastern wolf and the red wolf are merely the result of hybridization, and they do not represent ancient species that are independent from the main wolf or coyote lineage.
The same can be said for the Eastern coyote, which does have some wolf ancestry.
As for the ancient species that Nowak and other hitched their arguments to, a much more likely explanation is that the coyote and wolf lineages have produced animals that look more like wolves or more like coyotes.
The Arabian wolf is very much like a coyote. It doesn’t normally form large packs, and some individuals can be in the 25-pound range.
The Honshu wolf was even more similar to a coyote and was reported to have occasionally matured weighing in the 20 pound range.
And there is good evidence that coyotes during the Pleistocene were quite a bit larger than they are now.
It’s likely that ancient North American Canis had the same proclivities. Different conditions produced selection pressures for different sizes, and one could get wolf-sized animals out of the coyote lineage.
We’re seeing something similar going on with Eastern coyotes, which are evolving larger size and more powerful jaws in order to become better deer hunters. They get these traits from their wolf ancestors, but natural selection is also playing a role.
So one needs to be careful of someone trying to use the fossil record to argue against genome-wide studies.
The wolf conservation community has not accepted these findings. The US Fish and Wildlife Service just ignored the vonHolt study entirely.
David Mech, an expert on wolf ecology and behavior, said it couldn’t be true because he’d never seen a wolf and coyote mate in the wild– as if that somehow contradicted the DNA evidence that they have and continue to do so!
The paradigm says that the red wolf is the second wolf species. It is an ancient North America species that ranged all over the Eastern part of the continent.
Too bad the evidence for this entirely exists in rather superficial DNA analyses and the speculations of paleontologists.
The DNA simply says otherwise.
And the red wolf and the Eastern wolf are fictional animals, the result of overly imaginative hypotheses and not enough hard science.
Just because a fossil looks like an animal alive today doesn’t mean that it is the ancestor of the extant form.
Making inferences from fossils will always be haphazard and speculative to a certain point, and sometimes, the DNA evidence totally contradicts and falsifies these inferences.
That’s what happened here.
Too bad it’s not being recognized in an official capacity.
See related posts:
- The creature formerly known as the red wolf
- No unique “Eastern wolf” species
- The Canis lupus/Canis latrans species complex