Rice contributes over 20% of the calories consumed by humans each year. Korean bibimbap, Nigerian jollof, Indian biryani, Spanish paella, and countless other culinary masterpieces all begin with rice. So how did this humble grain end up in so many cuisines? Carolyn Beans investigates the global expansion of this beloved crop and the unintended consequences of its popularity. Lesson by Carolyn Beans, directed by Na Na Na Studio.