A Matter of Selection - Sam Albert

1. The leaves on the Brassica oleracea plants showed the most variation. The kale's leaves, for example, had oak-like leaves and took up a large radius around the plant. Others, like the cabbage leaves, were wide and didn't produce very many leaves. The characteristic with the most drastic difference was the height of the plants. Some plants (like the kale) towered over the others at three feet tall, while some (like the cabbage) reached just below a foot at ten inches. In fact, the cabbage and kale plants seemed to be polar opposites, with the kale large and impressive, and the cabbage short and dwarf-like. The many differences in these plants occurred both artificially and naturally, and all originated from the wild mustard plant.

2. Plant breeders might've selectively bred different kinds of the Brassica oleracea to get certain traits in the plants. They might've done this to increase the size of the flower/vegetable produced from the plant, or just to experiment with to see the various outcomes. Artificial selection is another name for selective breeding, and it was actually used to cultivate many Brassica oleracea plants from wild mustard. For example, breeders would suppress flower development to get broccoli, enlarge leaves to get kale, and keep the flowers sterile to get cauliflower. This species has been evolving over time, and our plants have the same genes and some similar traits that their ancestors had generations ago. Descent from modification, one of Darwin's key ideas, is how our plants have been inheriting their parents' traits. Yet another way variation between plants can happen is through genetic mutations, where the plant's DNA is altered in the gene, affecting the genetic makeup of the plant and potentially creating variation.

3. The members in our group all agreed that the stem of the Brassica oleracea plants seemed to be the most consistently similar. The stems averaged out at around half an inch to an inch per plant. Their lengths were usually several inches long, but could be larger or smaller. Almost everything about their anatomy was the same (color, size, radius). Our plants still aren't fully grown yet, so there is a possibility that their lengths and sizes could change. Stems aren't going to have a lot of genetic diversity due to their role in the plant's system: support and transport of water and nutrients. There's no real reason for the stem to change. Breeders did modify stems in kohlrabi plants, but since the plant is still growing the stems were still very much alike to the others.

4. If a breeder wanted a plant with a new or unique stem than from before, it could be done, but it would take some time. What they would have to do is find a parent plant with a similar type of stem to what they are looking for, and breed it with another matching parent plant to get their desired offspring. Then they would use the most suited offspring to breed again, and then repeat the process until they got a good result. So if they wanted a stem that was long and skinny, they would need to choose an existing Brassica oleracea plant that naturally has a long and skinny stem and breed it with another alike plant until they got the stem they wanted. It could take dozens of generations, and it could take four or five.

Kale plant with the broad, oakish leaves

Short cabbage plant with wide, curved leaves