Cats better than dogs from Evolutionary Perspective

Researchers say that the dog family originated in North America close to 40 million years ago, reaching a maximum diversity close to 22 million years ago.

All modern day cats in the Americas are descended from the pseudaelurus, which crossed over to North America using the Bering land bridge that once connected Alaska with Asia 18.5 million years ago. By contrast, evidence shows that dogs haven’t wiped out a single cat species.

This suggests that the cats must have been more efficient predators than most of the extinct species in the dog family. “Instead, competition among different carnivore species proved to be even more important for canids”, said lead author Daniele Silvestro at the Department of Biological and Environmental Sciences, University of Gothenburg, in a statement. The method employed included process-based speciation and extinction models that incorporated the process of preservation and the uncertainties connected to the age of the fossils, the researchers write in their paper published in PNAS.

“We usually expect climate changes to play an overwhelming role in the evolution of biodiversity”.

A team of global scientists has found cats and dogs have been fighting since ancient times, a report on ScienceDaily.com reports. Dogs, on the other hand, did not have such claws. It includes different variations of wolves and foxes. The dog family, as a distinct group of species, is widely believed to have begun in North America, as the oldest known dog-like fossil, around 40 million years old, was discovered in Texas. Today, only 9 species of the dog family live in North America. Interestingly, they found that the competition between the dog species and the four non-cat species was not particularly intense. It seems likely that fierce competition from cats was one of the factors responsible for this failure of the two families to diversify and survive. The sizes of these species gradually escalated and turned them into huge predators, with a few of them surpassing 66 pounds (30 kg) weight.

The evolutionary success of carnivorous animals is strongly linked to their ability to obtain food, meaning that there can be significant competition for prey when there is insufficient supply for the population. The limited amount of resources (preys) imposes strong competition among carnivores sharing the same geographic range. The research team compared canid fossils not just with felid ones but also with fossils belonging to other families, including bears, so-called bear dogs, false sabre-toothed cats, and Barbourofelidae, an extinct family of carnivores.