http://www.newsweek.com/first-proof-menopause-wild-chimpanzees-solve-human-evolution-mystery-1838158

Menopause has been observed in a population of wild chimpanzees for the first time, challenging long-held beliefs about the evolution of post-reproductive survival in humans.

The discovery, published in the journal Science on October 26, represents two decades of research into the Ngogo community of wild chimpanzees in Kibale National Park, western Uganda, by scientists from the University of California, Arizona State University and the Ngogo Chimpanzee Project.