The following article was written by my son Wilson, who has been researching some of the crops we grow. I sure didn't know the information presented here, but thought it was an interesting fact to show how we as humans adapt plants to suit our needs. And it's something we've been doing for thousands of years.
A Curious Case of Artificial Selection
Brassica oleracea is a species of plant that you would certainly recognize in one of its many forms. This one species includes cabbage, broccoli, cauliflower, kale, Brussel sprouts, collard greens, savoy, kohlrabi, and many others- the list is growing. All these seemingly absurdly different vegetables are actually the same species of plant!
In its wild and crazy form Brassica oleracea is known as wild cabbage. Wild cabbage has a ginormous native range throughout the coasts of the Mediterranean and the British Isles. This scattered stomping grounds is believed to be the reason for the vast genetic diversity expressed in this mindboggling variety.
Folks have been munching on B. oleracea for millennia. It was mentioned by Greek and Latin scholars before the dawn of Christian Rome. Early farmers domesticated the wild cabbage by selecting plants with certain traits and breeding them, a process called artificial selection.
Farmers started and continued the process of artificial selection over 10,000 years ago, selecting the desirable, but very different, traits in the exaggerated versions of kale, broccoli, cauliflower, and cabbage that we see today. Around 1600 A.D. farmers selected for variants of the plant that produced enlarged leaf buds. After many generations, we get plants with huge heads of tightly rolled leaves—we call it cabbage. Elsewhere, farmers selected and bred plants with enlarged flowering structures, recognizable to you and me as broccoli and cauliflower. The broccoli and cauliflower we eat are simply flower buds that have yet to flower (if you leave broccoli in the fridge too long you may notice yellow flowers peeking out). We have kale (believed to be one of the closest cultivars of its wild brethren) due to the diligence of farmers selectively breeding plants for large leaves. We stand on the shoulders of giants.
The definition of a species is a group of organisms capable of interbreeding and producing fertile offspring. All variants of Brassica oleracea are interfertile, resulting in weird hybrids that are gaining in popularity. Interesting combinations include- broccolini, broccoflower, brusselkale. I'm sure more are to come.
The Brassica oleracea family is just one example of plant genetics being modified by humans. Farmers have been selecting plants with superior, desirable traits to cultivate for thousands of years. Most plants we eat today have genomes that are not the same as their original wild ancestors.