Where did rice start?

The earliest evidence of rice cultivation comes from the Yangtze River Valley in China, where rice has been grown since at least 5,000 BC. Domesticated rice also arose in South Asia about 4,000 years ago and independently in West Africa around the same time. Today, rice is grown in more than 100 countries around the world, and it is the staple food for more than half of the world's population.