A Matter of Selection

Over time, the brassica oreala family has evolved into different variations of the plant. The plants have developed different colors, sizes, and leaf shape. In Willow Glen’s garden I have observed the plants and their differences. The greatest characteristic variation between each of the plants were the shapes of their leaves. The greatest range of variation was shown in the plant and stem color.

Siberian Kale:

• Dark green leaves
• Ruffled edges
• Purple stems

Cabbage:

• Green leaves
• Light green stem
• Wide leaves

Dino Kale:

• Bumpy texture
• Skinny leaves
• Dark dark green leaves
• Light green stem

Purple Cabbage:

• Smaller size
• Dark purple leaves
• Purple stem

Kohlrabi:

• Dark green leaves
• Purple stems

Broccoli:

• Tall
• Green stem

These many variations were over a long period of time. During this long period the plants genes changed to suite the environment. Artificial selection might have also been apart of the change in the plants. Humans would alter the genes to produce a better outcome. This is a form of selective breeding because humans are breeding the plants for particular traits. This type of change is not always the case. Some plants evolve through descent with modification. This event occurs when a plant is forced to adapt to a change in the environment and one specific trait becomes more dominant to better suite the change. These shifts in the plants genes cause natural variations in offspring over time. Mutations are also a large reason why the plant has changed so much over time.

The most consistent part of the anatomy in the brassica olercea family were the colors of the plants leaves and stems. Each of the leaves were a certain shade of green. For instance the cabbage, cauliflower, and dino kahle all had a shade of green leaves and green stems. I believe the reason why this trait never seemed to change is because there was never a need to or a change in the environment that forced them to change their color.

In order for a breeder to obtain a specific trait they would have to use different methods. For instance, the method most commonly used today is done by extracting a specific trait from a plant and embedding it into another. Another  more natural way would be putting the plant into a different environment causing it to adapt and change over time.