Fossils taken from the world famous La Brea Tar Pits in Los Angeles have revealed the evolution of predators during the last Ice Age was driven by climate change.

Researchers at the Page Museum explained concerns about current changes in the climate, and the impact they're having on today's world, prompted them to further study the connection between climatic warming and how that altered the development animals that lived during the end of the last Ice Age, dated between 50,000-11,000 years ago.

Evidence suggests weather back then was considerably unstable, with periods of rapid warming and cooling.

Two new studies published by Page research associates document significant changes through time in the skulls of dire wolves as well as saber-toothed cats.

"Different tar pits at La Brea accumulated at different times," said F. Robin O'Keefe of Marshall University, lead author on the dire wolf study, which was published in the journal Palaeontologia Electronica April 9, 2014. "When we compare fossils deposited at different times, we see big changes. We can actually watch evolution happening."

Through the fossil records, the researchers can trace the progression of the "animals adapting to a warming climate at La Brea," said O'Keefe. "Then humans show up and all the big ones disappear. We haven't been able to establish causality there yet. But we are working on it."

The emerging links between climate change and evolution needs further study and many questions remain, said O'Keefe; for instance, why do predators change in the ways that they do -- and what role, if any, did the appearance of humans play in the mass extinction at the end of the Ice Age.

"There is much work to be done on the specimens from the tar pits. We are working actively to bring together the researchers and resources needed to expand on these discoveries," said John Harris, chief curator at the Page Museum. "Climate change is a pressing issue for all of us, and we must take advantage of what Rancho La Brea can teach us about how ecosystems react to it."