A new study suggests that dogs have evolved from small, mongoose-like creatures due to cooler climates and open grasslands.
The study researchers came to this conclusion after looking at North American dog fossils. Some of them were as old as 40 million years, while others were no older than 2 million years, but they helped field experts learn new inside into how dogs evolved and how climate change can affect a species.
The ancient fossils looked more like modern day mongooses than modern day dogs, and Christine Janis, professor of evolutionary biology and ecology over at Brown University and study co-author, offered a statement explaining that the study is “reinforcing the idea that predators may be as directly sensitive to climate and habitat as herbivores”.
But the study also reinforces the idea that the Canidae family originated in North America. Members of the family are believed to have lived in this area for a long time before finally spreading to Eurasia and Africa 7 million years ago. As far as South America goes, dogs only made it there around 2 million years ago.
Professor Janis and her colleagues inspected elbows and teeth from 32 different species of dogs and noticed that they went through quite a transformation. Professor Janis informed that elbows, in particular, are a really good indicator of how carnivorous species have evolved over time.
It turns out that dogs initially had forelimbs that were made for grappling prey, not for running. The animals used to be ambush predators and only evolved into pursuit-pounce predators such as coyotes and foxes once temperatures started to go down. This opened up grasslands, which in turn provided them with space to run.
In fact, the researchers believe that the Canidae family didn’t develop their running ability because prey such as deer and antelope moved a lot faster than the prey they used to hunt, but rather because they finally had enough space to run. If they would have attempted to do so in the forest environment, they would have smacked straight into a tree.
And their teeth got stronger because they now had to bite into prey living in gritty savannah environments, rather then prey living in damp forest environments.
Soon after this they transformed into what Professor Janis describes as “dogged, follow-a-caribou-for-a-whole-day pursuers”. Wolves, basically.
The study was published recently, in the journal Nature Communications.
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