Final answer:
The selective breeding effort at the University of Illinois Agricultural Experiment Station aimed to increase the oil content in corn, which is part of the long history of selective breeding. This practice, coupled with agricultural changes in the early 20th century, contributed to significant increases in corn production.
Step-by-step explanation:
The selective breeding experiment mentioned in the question refers to the historical efforts to increase the oil content in corn through selective breeding. The University of Illinois Agricultural Experiment Station began these efforts in 1896, as part of the broader agricultural revolution that significantly changed the way seeds were produced and distributed. Although the exact figures regarding the increase in oil content are not provided in the references, it is clear that the cultivation and breeding of crops like corn have been dramatically influenced by both natural selection and human intervention over thousands of years. Corn's transformation from a wild grass called teosinte to modern maize is one such example of selective breeding achieving desirable traits like larger ears and increased yield.
In the context of agricultural practices, the decision of farmers to purchase seed rather than save their own led to the development of seed companies and the widespread distribution of hybrid seeds. This practice contributed to the tenfold increase in corn production reported in North Dakota since 1972 and reflects the impact of converging crop prices and farmers' responses to them in adjusting their crop mixes.