Nature has been most helpful to scientists aiming to study climate change, and thus, changes to the planet are very well documented. It has long been thought by scientists though that while herbivores adapted to the change in climatic conditions, carnivores did not. The recent findings of a study regarding the evolution of dogs has, however, disabused us of that notion.
On Tuesday, Nature Communications released a study by a group of scientists that analyzed North American wolves and fossils that were as old as 40 million years. It was found that these prehistoric dogs had an evolutionary path that was directly linked to climate change. A lot of the main evolution points of these animals occurred in tandem with major shifts in the climate.
The North America known today is very different from 40 million years ago. Back then, the area was a warm woodland. Canine ancestors living in that North America were small animals and bore more of a resemblance to a mongoose. Native dogs 40 million years ago had forelimbs that were not suited to running and instead relied on ambush methods. After a few million more years, though, the forests thinned and gave way to grasslands as the climate became cooler and drier. Herbivores evolved right along with the times, and long-legged animals like the bison and deer proliferated. The prehistoric dogs also were found to evolve at this time from their smaller counterparts.
Now that there was enough room to run, and less possibility of springing from dense bushes to trap prey, predators adapted also. Upon examination of the over 32 species of fossils, it was determined that the dog's elbow joints and forelegs evolved to facilitate long-distance running, offering more support and less flexibility. Their teeth became more durable as well, which is speculated to have made it easier to deal with dry raw hides or perhaps the grit of the high plains mixed in with their meat. The dogs evolved from ambushers to the likes of predators like foxes and coyotes, and eventually into wolves, who use more pursuit then pounce methods. These species are so closely linked in the evolution gene pool that modern day scientists still make surprising discoveries.
Christine Janis, who is a co-author of the study and professor of ecology and evolutionary biology at Brown University, said that this study may have a broader impact than on dogs alone.
"It's reinforcing the idea that predators may be as directly sensitive to climate and habitat as herbivores."
In inarguable fact, though, is that the study has proven that climate change has had a dramatic impact on both predators and their prey.
[Photos Courtesy of Discovery News and Mauricio Anton / Brown University]