After 9,000 years of cultivation, rice has reached its thermal limit

Rice has historically been a heat-loving plant. In fact, the wild ancestor of cultivated rice once grew primarily on the sweltering, rain-swept Malay and Indochina peninsulas as well as the islands of Southeast Asia. It wasn't until Earth's climate warmed after the last ice age that wild rice substantially spread into central China and South Asia, where it was independently domesticated by humans in two events that arguably rank among the most important in the history of our species.