A week-old panda cub sleeps in an incubator at the Chengdu Research Base of Giant Panda Breeding on June 30, 2015 in Chengdu, China. The twin female cubs were born by artificial insemination to seven-year-old Kelin on June 22. China's Sichuan province is home to the majority of the the world's nearly 1,900 endangered giant pandas. (Photo by John Moore/Getty Images)
