For most of my life, scientists believed that the present era was still the Holocene. Glaciers retreated with a global warming trend around 11, 650. Man went from being the apex predator over much of the world and became the apex consumer. Agriculture allowed our populations to expand, and we started to give up our wandering ways and became “civilized.”
It was generally believed that the past few centuries are but a continuation of this age, but now a growing number of scientists believe we have left the Holocene and entered into the Anthropocene. Several scholars have issues with this new distinction, but I think it is quite useful. In this era, human activity is the main factor affecting climate and ecology, which is why the age is named for the Greek word for human (anthropos).
The best argument I’ve seen for when this era began is 1610. In this scenario, the era is dated to when European disease and conquest killed off enough Native Americans and enslaved and enough African had been enslaved to allow forests to grow back in former agrarian fields. This process started in 1492, but by 1610, enough of those trees had grown to remove enough carbon dioxide from the atmosphere to push the planet into the Little Ice Age.
Darcy Morey and Rujana Jeger have a great model for understanding dog domestication as a change in trophic strategies. In the Pleistocene ecosystems, most wolves were mesopredators, playing second fiddle to an ecosystem full of cave lions, machairodonts, large bears, and cave hyenas. When these wolves hooked up with people, though, they hitched their wagon to the species that often behaved as the apex predators in the ecosystems. When humans switched to agrarian lifestyles during the Holocene, humans became apex consumers, and dogs joined us as beneficiaries of being allied to that apex consumer species. During the Holocene, many wolves became apex predators, as the cave lions and other large predators became extinct.
I’ve always liked the framework that Morey and Jeger derived in this paper, but now that we’re entering into a new geological age, maybe we need to look at the change in trophic strategies of wolves in this new age.
Morey and Jeger don’t have a good framework for what happened to wolves in the Anthropocene, but across Eurasia and North America, wolves were gone from many human-dominated landscapes by the first decades of the twentieth century. They existed only in isolated areas in Western Europe, and in the lower 48 states of the US, they lived only in Minnesota and in an isolated region in East Texas and Louisiana, where the taxonomically controversially red wolves were located.
Large pack-hunting wolves were really in quite a bit of trouble. In the United States, the coyote population began to expand out of its Western core range into the Great Lakes States. They eventually made to New England and the Maritimes of Canada, and they hybridized with relict wolves and the expanding population of domestic dogs. Coyotes eventually colonized all the Eastern states, and as they did so, they largely became the apex predators in many parts of their range.
But in the 1960s, attitudes about wolves began to change. Many nations protected wolves, and there were often introduction plans in the works. By the early decades of the twenty-first century, wolves were making significant comebacks in Germany and Italy. The wolves in Italy were often living very much like stray domestic dogs, living large at garbage dumps. Wolves live near large cities in Germany, and how these wolves are going to adapt to living in such human dominated environments is going to be a major question for researchers.
And in throughout Eurasia, we began to see that domestic dogs were mating with wolves. Indeed, it is now estimated that a majority of wolves in Eurasia have relatively recent dog ancestry.
Similarly, as coyotes expanded in North America, their genes began to work their way into the wolf population. Yes, coyotes in a large part of the US have wolf ancestry, but we also have discovered that wolves across North America have coyote ancestry. Indeed, one interesting thing about these genome comparisons is that coyotes and wolves are much more closely related than we initially gleaned form mitochondrial DNA analysis. The calculation is that the gray wolf and the coyote last shared a common ancestor around 50,000 years ago. This recent common ancestry has a taxonomic implication, which is that coyotes are themselves a divergent form of gray wolf in much the same way domestic dogs are.
In the Anthropocene, the wolves that have done the best have been the domestic dog and the coyote. The domestic dog’s ability to ingratiate itself into human society or live very nicely as an opportunistic scavenger/hunter on the periphery of humanity is a great gift. The coyote can live as an opportunistic scavenger/hunter as well, and it also can live very nicely as a mousing fox or pack up and hunt deer.
Gene flow among wolves, coyotes, and dogs has made these entities much more fuzzy than we once thought they were. Dog genes are working their way into both the coyote and wolf population. Strange pelt colors are popping up in the wild animals. The black coloration in domestic dogs was conferred onto the North American wolf population during the Holocene, but this same mutation for melanism has entered the coyote and Italian wolf population in very recent years. Dogs have introduced dewclaws on the hindlegs to some wolf populations, and I have seen photos of Eastern coyotes that have those hind dewclaws as well, which likely were introduced through breeding with domestic dogs.
Coyotes in the East are evolving larger size to become better predators of deer, but becoming larger and more effective ungulate hunters will have a trade-off. As carnivorous mammals grow larger, they become more and more dependent upon large prey to survive. Very large wolf-like coyotes will lose their ability to live well on small prey and garbage.
So in the Anthropocene, dogs remain allied to the apex consumers. Some coyotes operate as apex predators, and some wolves live as opportunistic scavengers.
And as these creatures adjust their trophic strategies in a much more predator tolerant world, the pseudo species barriers that exist among wolves, coyotes, and dogs can break down. Hybridization among these creatures is likely to be a major feature of their continued evolution, a definite feature and not a bug.
These canids thus make the leap with us into this human dominated age, an age that is experiencing a mass extinction of amphibians and great retrenchment of large sharks and big cats.
Yet they are still there. Evolving as the winds change. Winds that we ourselves are changing and are only now starting to understand.
