What does the evolution of wild cabbage indicate?

The cultivation of wild cabbage as a food plant has been practiced for more than 2000 years. As per the requirement, farmers cultivated wild cabbage by the selection of desired traits for many years. This method of artificial selection generated different variations of the crop like broccoli, kale, kohlrabi, red cabbage, and cauliflower having individual characteristics.

Broccoli was bred for arrested flower development while cauliflower was bred for sterile flowers and kohlrabi for swollen parts.