The Week in Pictures: Jan. 18 – 25

Macaque monkeys Zhong Zhong and Hua Hua play at a non-human primate facility at the Chinese Academy of Sciences in Shanghai on Jan. 20. The pair are the first primates to be successfully cloned.

Since Dolly’s birth in 1996, scientists have cloned nearly two dozen kinds of mammals, including dogs, cats, pigs, cows and polo ponies, and have also created human embryos with this method. But until now, they have been unable to make babies this way in primates, the category that includes monkeys, apes and people.