Ancient wheat was generally einkorn, nature's first and oldest wheat. It has been replaced almost everywhere by hybrids and eventually GMOs that are much shorter. Being shorter makes the plant more robust and able to grow in places the taller grasses can't.

The hybrids were a miracle of science that enabled the feeding of vastly more numbers. But like most scientific miracles, there are trade-offs. The most prominent one being that the new wheat is not as healthy, or even downright harmful.