Family means a lot on Cayo Santiago, an island and monkey research colony off the coast of Puerto Rico. The colony of rhesus macaques living on the island since the 1930s has allowed scientists to trace kinship ties and effects across an extended community. Anders Kelto/NPR hide caption

itoggle caption Anders Kelto/NPR

Sure, it's cute. But that voice! Lennart Tange/flickr hide caption

itoggle caption Lennart Tange/flickr

A first-year student is greeted upon arrival at University College in Utrecht, Netherlands, on August 16, 2010. Robin Utrecht/AFP/Getty Images hide caption

itoggle caption Robin Utrecht/AFP/Getty Images

Gorillas are fine with being herbivores, like this one at a Seattle zoo. But humans evolved as omnivores. Is diet destiny? Ted S. Warren/AP hide caption

itoggle caption Ted S. Warren/AP