Wolf teeth shed light on survival of species over thousands of years

Grey wolves may have been able to survive a transition from the ice age to the modern age unlike other animals because they were able to change their diet, according to a new study.

A research projectout of Carleton University and in conjunction with the Canadian Museum of Natureexamined the skulls of 31 wolves found in Yukon, near Old Crow and Dawson City.

By looking at the animals'teeth, researchers discovered evidence that when the ancestors of horses went extinct in Beringia a stretch of land that used to exist between present day Siberia and Yukon wolves changed their diet to large-bodied cervids. This happened between12,000 to 15,000 years ago toward the end of the Pleistocene era.

The report said the survival of the cervids animals like deer, moose, elk or caribouwas key to the survival of the wolves.

"For a large predator to completely switch from one prey to anotheris very striking," said Grant Zazula, one of the paleontologists who authored the study. "Animals don't do that, they evolve these predator-prey relationships over hundreds of thousands of years."

The research shows that wolves are great and adaptable survivors, he said.

Why didn't other animals survive?

Zoe Landry, a PhD candidate and lead author of the study, used the Canadian Museum of Nature's scanning electron microscope to examine the wolves' teeth.

Two universities in the U.S. also helped out with chemical analysis.

According to the report, published in a journal called Palaeogeography, Palaeoclimatology, Palaeoecology, the chemical composition of the skulls contained elements found in caribou and not in other prey.

Danielle Fraser, director of the Beaty Centre for Species Discovery and a research scientist with the Canadian Museum of Nature, said the discovery is remarkable.

But, she added, there are still plenty of questions.

For example, why did scimitar cats and Arctic lions not make the same switch?

"Wolves are pack hunters and we have no reason to believe they weren't pack hunters in the Pleistocene like they are now," Fraser said. Cats, however, don't tend to be pack hunters so that could be a behaviour reason for the difference, she said.

It's possible the caribou put up more of a fight than the ancient horses.

"Hopefully by looking at some of these same measures that [Landry] used, we can try to get at what set wolves apart from some of the things that didn't make it through," Fraser said.