A new study on 40 million year-old North American fossils shows that dogs evolved as predators due to climate change.
UNPRECEDENTED DISCOVERY
Though it has long been accepted that the evolution of herbivores has been affected by climate change and its impact on vegetation, the same effect was not thought to have occurred to carnivorous creatures.
“It’s reinforcing the idea that predators may be as directly sensitive to climate and habitat as herbivores,” said Christine Janis, a Brown University evolutionary biologist who worked on the study. “Although this seems logical, it hadn’t been demonstrated before.”
Borja Figueirido of the Universidad de Málaga is the lead author of the study, which was published in in the Nature Communications journal.
DOGS ADAPTED TO GRASSLANDS
Dogs used to be primarily ambush predators. A drop in the global climate created grasslands in the North American ecosystem, and the species would require the ability to hunt by pursuit to adapt. Researchers noticed changes in the forelimbs of the dogs that would have provided them advantages for running in the grassland terrain. Specifically, the frontal appendages evolved to become more inflexible.
OTHER FINDINGS FROM THE STUDY
Aside from better forelimbs for running, the scientists also observed that climate change influenced the teeth of the dogs. As more and more grass grew, dogs developed more durable teeth to make it part of their diet.
Other findings of the report indicate that dogs used to vary in size more than they do today. Jack Tseng of the American Museum of Natural History, another author of the study, told Forbes “The range of body sizes and diets inferred from fossil dog specimens are broader than what is seen in living dog species for example, there are fossil records of cat-like and hyena-like dog species, specialized predators that are entirely extinct.”
DOGS WERE LIKE CATS
Dogs are members of the Canidae family, and their evolutionary history is believed to have began 50 million years ago, when their lineage diverged from cats. As the Mirror mentioned, this new study suggests that dogs became less “cat-like”, because evolution forced them to abandon the ambush-based hunting method that cats still use today.
Though we generally consider cats to be meeker creatures, they used to be better hunters than dogs. As Kimiko pointed out at Clapway, a recent study shows cats eliminated 40 species of ancient canids.
For more on the history of dogs, check out the Taimyr Wolf.
Photo credit: Brown University.
