A Canadian geographer who helped pinpoint the events that led to the demise of woolly mammoths says he’s concerned the same combination of factors could threaten modern species.

“In the 21st century, we’ve altered huge amounts of land,” says Glen MacDonald, the UCLA geography professor who was part of research team that identified climate change, habitat loss and human encroachment as reasons for the extinction of most woolly mammoths 10,000 years ago. “If mammoths couldn’t handle it when it was a much slower change, I really worry for all species today.”

Many previous theories on the mammoths’ decline blamed one event. The UCLA team’s research was the first time scientists mapped and dated multiple aspects of the era at the same time.

MacDonald says there were thriving populations of mammoths in the Yukon, northern Alberta and other northern sections of Canada 30,000 to 40,000 years ago. He believes that at some point, mammoths were found in most provinces.

But around 20,000 years ago, at the peak of the last ice age, mammoths were struggling to survive, their populations decreasing. “It was formerly thought that they really adapted to the ice age,” MacDonald says. “Now, what we’re finding is that’s not necessarily true, especially for northern populations in places such as the Yukon and Alaska. The ice age was pretty rough on them.”

As the last ice age ended around 15,000 years ago, the climate became warmer and vegetation sprouted. Initially mammoth populations increased, but as the land changed to more coniferous forest and shrub land, the open-terrain habitat that mammoths thrived on began to shrink.

When a cold snap hit the northern hemisphere about 13,000 years ago, mammoth populations declined but were not wiped out completely. Around the same time, humans began hunting mammoths in Alaska and the Yukon. MacDonald says that with environmental and habitat changes already occurring, even a small amount of hunting might have been enough to push mammoths to extinction.

The last mammoths in Canada died out around 9,000 to 10,000 years ago, though the animal didn’t disappear completely until about 4,000 years ago, when the last of the species died on Wrangel Island, off the coast of Siberia.