for National Geographic News
Ancient climate change cornered the woolly mammoth into a shrinking habitat, but humans delivered the final blow by hunting the species into extinction, a new study suggests.
Climate change and hunting have long been blamed for forcing the mammoth into decline at the end of the Pleistocene era about 10,000 years ago. The last mammoth died out 4,000 years ago, experts estimate.
But this study marks the first time that the massive, shaggy-haired animal's demise has been explained using combined population and climate change modeling, researchers say.
Previously, separating the individual impact of each factor on the mammoths had been difficult.
For instance, warming temperatures that emerged during and immediately after the late Pleistocene opened up new territories for human migration—ushering them into the woolly mammoth's backyard.
David Nogués-Bravo, of the National Museum of Natural Sciences in Madrid, Spain, led the new research, which was published recently in the journal PLoS Biology.
"Only in the last [few] years we have [had] robust paleoclimatic simulations" that chart climates for historical periods, Nogués-Bravo said.
"These paleoclimatic maps allow us to model the area covered by the climatic niche of the woolly mammoth."
That area is then considered a variable when modeling human-hunting intensity, he explained.
The researchers charted the climate and distribution time line of the mammoth from 126,000 to 6,000 years ago by modeling ocean currents, rainfall, and other factors.
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