Ancient Cats Drove Many Dogs to Extinction
August 16, 2015
Is this why dogs hate cats?
Maybe not-but a new study finds that the rivalry has been profoundly deadly for millions of years, with dogs, especially, getting the short end of the stick.
Cats and their close relatives have often beat out species within the dog family in the ceaseless competition for food, the study finds. In the process, it concludes, as many as 40 of the species related to dogs were pushed to extinction. The cat family on the other hand got through relatively unscathed.
The research finds that competition overall played a larger role in the evolution of the dog family-wolves, foxes, and their relatives-than climate change, normally an overriding factor.
“We usually expect climate changes to play an overwhelming role in the evolution of biodiversity. Instead, competition among different carnivore species proved to be even more important for canids,” the dog family, said Daniele Silvestro of the University of Gothenburg in Sweden, lead author of a report on the findings.
Silvestro and colleagues analyzed over 2000 fossils and found that the arrival of the cat family to North America from Asia had a deadly impact on the diversity of the dog family. The research is reported this week in the journal Proceedings of the National Academy of Sciences.
The dog family originated in North America about 40 million of years ago and reached a maximum diversity around 22 million of years ago, when more than 30 species inhabited the continent, according to the scientists. Today, only nine species of the dog family live in North America.
Over eons, they gradually grew larger and specialized to become large predators. Some of them exceeded 30 Kg (66 pounds) and were among the largest carnivores in North America. Although several large carnivores today face a higher extinction risk than smaller species, the authors of the study found no evidence of a similar pattern in ancient canid species.
But carnivores' evolutionary success is inevitably tied to their ability to get food. The limited amount of prey forces tough competition among carnivores ranging the same area, Silvestro and colleagues note. For instance African carnivores such as wild dogs, hyenas, lions and other felids (members of the cat family) are constantly competing with each other for food.
North American carnivores in the past might have followed similar dynamics and much of the competition is found among species of the dog family and from ancient felids and dogs, the scientists say.
Interestingly, while felids appeared to have a strongly negative impact on the survival of ancient dogs, the opposite isn't true, the study found. This suggests that felids were more efficient predators than most of the extinct species in the dog family.
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