Matheus Bertelli/PexelsRice is the most popular food in the world, providing sustenance to more than 3.5 billion people each day.Rice is deeply embedded in food, daily rituals, language and spirituality. It is easy to take it for granted. But where did rice come from? And how did it spread to become the foundation of global food security?Early origins in China and IndiaIn the lower reaches of the Yangtze River, China, Oryza sativa rice grew 100,000 years ago. It was first gathered by humans 24,000 years ago, and cultivated 13,000 years ago. Changes to the plant through selective breeding resulted in a domesticated plant distinct from the wild varietal about 11,000 years ago.There is debate about how early forms of domesticated rice developed outside of China, but there is evidence of parallel rice cultivation in India along the Ganges in Uttar Pradesh as early as 6500 BCE. One possibility is that the two most common subspecies of rice, short-grained (japonica) and long-grained (indica) developed separately: the former in China and the latter in India. A related theory is that indica is a hybrid between a local Indian rice and japonica, introduced to India around 2500 BCE.African rice: the other origin storyAnother rice species, Oryza glaberrima, developed in Africa some 2,000 years after rice was domesticated by farmers in Asia. African rice is lower yielding than Asian rice species, but is drought and pest resistant. It tolerates severe climatic extremes, parasites and viruses, and will flourish in poor soil without irrigation or weeding. African rice is better suited to the dry, harsh climate of Western Africa. Kold Shots/Pexels But both historically and today, African rice is more prone to “shattering”, losing its seeds before being harvested, rather than clinging to the plant. This trait was successfully bred out of Asian rices over a long period to ensure maximum crop yields.Migration, wars, trade and slaveryThe migration of prehistoric farmers spread rice across Southeast Asia.Archaeological evidence from 4,000 years ago suggests farming techniques were introduced to Southeast Asia – including modern day areas of Vietnam, Cambodia, Myanmar and Thailand – by distant migrants from South China, rather than being learned from neighbours or through experimentation. There is a possibility the same scenario was replayed in numerous regions across Eurasia as rice spread across the globe.The movement of armies also brought rice to new parts of the world. Naturalists who accompanied Alexander the Great’s campaigns in India brought rice home with them to Ancient Greece and Macedonia around 320 BC.Invading Moors, from North Africa (present-day Morocco and Algeria) in the eighth century brought rice to the Iberian peninsula. Crusaders returning from wars in the Middle East brought back small quantities of rice to Europe in the 11th century.From the second century, overland trade along the Silk Road and maritime trade from the Indian Ocean to the Mediterranean brought rice to Central Asia and Europe. Rice was not cheap to ship, so as an import it would have been a luxury – like exotic spices – rather than a staple commodity. This scroll is dated before 1353, based on illustrations from the 12th century. Titled Rice Culture, it depicts the cultivation and harvesting of rice in China. The Met Colonisation and the transatlantic slave trade brought rice to the Americas from the 16th century. Spanish colonists brought Asian rice to Central and South America, while the transatlantic slave trade brought African rice species to North America.Enslaved Africans from the rice coast countries of West Africa introduced techniques for irrigation and tilling the soil using hoes, so the crop could be grown in the North American climate.Devastatingly, the African expertise led to an increase in the slave trade, because improved rice production made it easier to feed a growing population of enslaved Africans.Rice as ritualThe importance of rice in many cultures is embedded in the daily life, cultural practices, rites and rituals. In Thailand, the centrality of rice is reflected in language: kin khao, meaning “let’s eat”, literally translates to “eat rice”.Annual royal ceremonies in Cambodia, Myanmar, Thailand and Japan mark the beginning of rice growing season in the first half of May. Every year the King and Queen of Thailand preside over the Buddhist Royal Cultivation Ceremony, and the Brahmin Royal Ploughing Ceremony, combining prayers and offerings to ensure successful harvests.In Japan, symbolic rice planting by the Emperor is followed in June by an elaborate Shinto ritual, Mibu no Hana Taue. This celebrates the rice deity with a pageant of decorated cows, traditional festive dress, songs and music.Rice is also central to Hindu rituals, from birth to death. A baby’s first solid food is sweet rice marking the annaprashana rite of passage. Rice is an offering and a blessing at weddings, and serves as an offering for the journey into the afterlife.The future of riceTraditional rice growing is water intensive. Methane emissions from growing rice make it the third highest contributor to global food-related agricultural emissions.New techniques are being developed to mitigate the environmental impact of rice cultivation while maintaining production levels to meet growing demand.The secret may lie in the past, as researchers investigate ancient rice DNA in an attempt to produce the next hybrid that will once again change how rice feeds the world.Garritt C. Van Dyk has received funding from the Getty Research Institute.