Genetic modification by people have produced virtually all plants and animals in the western world. Broccoli, cauliflower, cabbage, kale, kohlrabi, and brussels sprouts are all derived from a wild mustard plant in Europe. None of these vegetables exist but-for early genetic engineering.
Similarly, all dogs, cows, pigs, sheep, and chickens are modern man-made creations. Scientists speculate that dogs “self-domesticated” — that is, got it into their dog brains that pets have great lives and befriended people on their own. However, the rest are all manufactured. They derive from wild species bred into something different to yield meat and milk.
One important milestone came in 1909 when food scientist George Shull developed a new way to manipulate corn and other plants.
Before Shull, people would cross-breed plants for desirable strains. For example, they might cross a tall rice plant that produces poorly with a short rice plant that produces a lot to make a tall rice plant that produces much more than either parent.
Shull theorized the genetics could be better controlled by repeatedly inbreeding to cancel out random genetics. He repeatedly inbred two strains of corn plants, each with individual desirable traits. As other scientists already knew, the inbred plants produced poorly. The plants were short with few ears of corn and the ears had few rows.
Eventually, after the plants were inbred to the basics he then cross-bred them. The crossed the two basic inbred pairs blended their genetics to produce dramatically better, genetically predictable corn.
Shull’s theories went on to other fields, radically changing food technology. His techniques are still in use today though, in some countries, more sophisticated direct genetic modification (GMO’s) are more common.