Caribou and Reindeer
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(Olivier Morin/AFP/Getty Images)
Caribou and reindeer are classified by scientists as the same species, with the domesticated reindeer dispersed across parts of Europe and Asia and the wild caribou found in North America and Greenland.
Russell Graham, associate professor of geosciences and director of the Earth and Mineral Sciences Museum at Penn State University, says global warming will most harm the animals adapted to the coldest environments, primarily those accustomed to life in the Arctic.
That group includes these large mammals, which have become symbols of Christmas. Their insulated fur and lack of sweat glands allow them to survive harsh winters, but those adaptations also make longer, hotter summers very difficult to endure.