Rice is a variation of grass, so is wheat. How can anyone believe there was no African specie. However, other food staples took hold in Africa. Corn became more staple and require less water.
Some modern day people, forgets about ancient civilization contribution to our existence. Every human on this planet past and present can be credited for food production,medicine, etc for prolonging our existence.
Look at the ole USA we are a melting pot, people with ideas and thoughts created modern things that enhance our lives at a such fast pace that is beyond the realm of imagination.Some day in the future there may be arguments who created such things first,the Western world or the Eastern world.
Some people are stuck in their ways,they are hard nuts to crack.