Dogs Evolved with Climate Change to Turn into Pursuit Predators
It turns out that dogs may have evolved due to climate change. Scientists have taken a closer look at North American dog fossils as old as 40 million years and have found that the evolutionary path of whole groups of predators may be a direct consequence of climate.
"It's reinforcing the idea that predators may be as directly sensitive to climate and habitat as herbivores," said Christine Janis, one of the researchers, in a news release. "Although this seems logical, it hadn't been demonstrated before."
The climate in North America's heartland was warm and wooded about 40 million years ago. During that time, dogs were small animals that would have looked more like mongooses than the dogs alive today. Their forelimbs were not specialized for running, and retained the flexibility to grapple whatever meal happened to walk by.
Beginning just a few million years later, though, the global climate began cooling in North America and the continental interior became much drier. The forests slowly gave way to open grasslands.
In order to see if this transition affected the evolution of carnivores, the researchers examined the elbows and teeth of 32 species of dogs spanning the period from about 40 million years ago to 2 million years ago.
The researchers found that there was a telltale change in the elbows that caused the dogs to become specialized in endurance running. In addition, the dogs' teeth trended toward greater durability, consistent with being able to eating prey that had been rolled around in the grit of the savannah.
The findings reveal a bit more about dog evolution and show how their environment altered them over time.
The findings are published in the journal Nature Communications.
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