The development of agriculture, or the intentional production of plants and animals for human use, allowed people to settle in one place and form villages and cities. Approximately 10,000 years ago, the domestication of plants and animals for human use began to develop rapidly. As hunter-gatherers became farmers, they learned to select and save seeds from plants that produced the best crops and to breed the animals that were best suited to meet people’s needs. The first steps of domestication probably happened by accident, but soon farmers deliberately practiced selective breeding to develop crops and livestock more suited to their needs.11 Selective breeding was likely the earliest form of agricultural biotechnology used by humans to improve the genetic characteristics of plants and animals. Agricultural biotechnology includes a variety of tools (including traditional breeding techniques) that alter living organisms, or parts of organisms, to make or modify products; improve plants or animals; or develop microorganisms for specific agricultural uses.16
Types of Agricultural Biotechnology
1. Selective Breeding
Selective breeding (also known as artificial selection) is a technique still extensively used by crop and livestock producers today. Selective breeding allows producers to select and breed parent organisms with desired traits to produce offspring with more desirable characteristics. This process creates offspring who are genetically superior to the parent organisms, thus improving plants and animals with each generation. The successful results of selective breeding throughout the years can be seen in crop and livestock production today.
Many crops, including wheat, have been genetically improved through selective breeding. Dr. Norman Borlaug was a research scientist assigned to improve the wheat plant in Mexico. By studying genetics and utilizing selective breeding, he was able to develop short-strawed, disease-resistant wheat that was high yielding. Dr. Borlaug is known as the “Father of the Green Revolution” for his improvement of wheat and was awarded the Nobel Peace Prize for a lifetime of work to feed a hungry world.4
In the livestock industry, today’s cattle are also evidence of successful selective breeding. Dairy and beef cattle are both highly efficient animals that produce more milk and meat than in years past. Today, there are only 9 million dairy cows in the United States compared to 25 million cows in 1950; however, today’s dairy cows are producing 60% more milk.12 In 1944, the average dairy cow produced 548 gallons of milk in one year. The average dairy cow today is able to produce 2,429 gallons of milk in one year.13 Beef production has seen similar success. Compared to 1977, today’s beef ranchers are producing the same amount of beef with 33% fewer cattle.10 It is important to note that proper nutrition, better health care, and good animal husbandry also play a key role in improving genetics.
2. Bioengineering (BE)/Genetic Engineering (GE)/Genetically Modified Organisms (GMO)
Bioengineered (BE), genetically engineered (GE), and genetically modified organisms (GMOs) are all terms that can be used interchangeably. A genetically modified crop is a crop that has had its genetic makeup altered in order to produce a more desirable outcome, such as resistance to disease, drought tolerance, or change in size.1 Bioengineering differs from selective breeding because scientists directly manipulate (introduce, delete, or modify) specific genes within an organism’s DNA.
Currently, there are a variety of bioengineering methods for crop modification including, transgenesis and gene silencing. Both of these crop modification techniques will be highlighted in this lesson.
- Transgenesis: During transgenesis, scientists take the desirable gene from one organism’s DNA and transfer it to another organism’s DNA, creating a new, stronger product—one that is impossible to produce through traditional breeding.1 During activity two, examples of transgenetic crops include the rainbow papaya, Bt corn, soybeans, cotton, and golden rice.
- Gene silencing: Whether using RNA interference (RNAi) or Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), this form of bioengineering can be used to specifically select and silence certain genes. Often times with crops, it is used to mute undesirable components or traits. During activity two, examples of crops modified using a gene silencing technique are the Arctic apple and the Innate potato.
Currently, there are 13 genetically modified crops that have been approved and are available on the U.S. market: corn, soybeans, cotton, canola, sugar beets, alfalfa, papaya, squash, apples, potatoes, eggplant, AquAdvantage salmon, and pink pineapple. To learn more about the safety and regulatory process of GM crops refer to the Background Agricultural Connections section of the lesson plan, Evaluating GMO Perspectives.
