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Explain the process of evolution of wild cabbage.

Farmers and breeders allowed only the plants and animals with desirable characteristics to reproduce, causing the evolution of farm stock. This process is called artificial selection because people (instead of nature) select which organisms get to reproduce.This process is known as artificial selection. It plays an important role in organic evolution because it is parallel to natural selection. It helps to produce new species having useful traits in less time.It is from wild mustard plants such as cabbage cauliflower etc have have been artifcially selected.
In his On the Origin of Species by Means of Natural Selection, Charles Darwin drew parallels between natural selection in the wild and the plant and animal breeding orchestrated by farmers, a practice encompassed by what biologists call “artificial selection”.
Artificial selection requires a farmer, in addition to natural environmental circumstances, to determine which individuals possess the key characteristics to pass on to the next generation, allowing only the most desirable individuals to breed.
Farmers choose to breed those individual plants that maximize desirable qualities and minimize undesirable ones. In the domesticated varietal of a wild species the desirable quality under selection, such as the sweetness of fruit or the size of a particular structure, may become amplified over time, exaggerated over the average wild condition.  Or a farmer may save from obscurity an individual with a characteristic that is rare in the wild or in the most common farmed variety, such as a particular flower color, or a nontoxic mutant almond, making the unique plant a progenitor of a new varietal.
  The wild plant is a weedy little herb that prefers to grow on limestone outcroppings all around the coastal Mediterranean region.  It is a biennial plant that uses food reserves stored over the winter in its rosette of leaves to produce a spike of a few yellow flowers at the end of its second summer before dying.  Those nutritious leaves make its domesticated derivatives important food crops in much of the world now.  Enterprising farmers over the last several thousand years contributed to domesticating several distinct lineages of B. oleracea, each amplifying different parts of this wild plant to produce several vegetable varieties, or cultivar groups or sub species.  kale and collard greens (ssp. acephala), Chinese broccoli (ssp. alboglabra), red and green cabbages (ssp. capitata), savoy cabbage (ssp. sabauda) kohlrabi (ssp. gongylodes), Brussels sprouts (ssp. gemmifera), broccoli (ssp. italica), and cauliflower (ssp. botrytis)..  These varieties look dramatically – sometimes comically – different but are nonetheless considered to be the same species because they are all still interfertile, capable of mating with one another and producing fertile offspring.

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