In the beginning, there was natural selection. This is what happens when plants are left to their own devices and are pollinated by wind, rain, insects, or birds. Because these chance crossings have been happening for millions of years, the germ plasm of these open-pollinated plants has stabilized. In other words, you can plant their seeds and get plants that are basically the same as the parent plants. Eventually, people learned how to produce special plants by allowing two selected, closely related parents to cross-pollinate. This is called hybridization. Whenever you want seeds of that special plant (hybrid), you have to isolate the two specific parents so you get genetic material only from those specific sources. That's why you get a lot of surprises when you collect and plant the seeds of a hybrid that has matured in your garden and not in isolation. Plants make hybrids among themselves all the time, but the science of plant breeding did not begin until Gregor Mendel showed how genetic traits were inherited. Genetically engineered plants are a giant step beyond hybrids, which, as we mentioned, are the result of two closely related plants being crossed. Scientists now have the ability to determine exactly which genes control every characteristic of every living organism—and they have developed techniques that allow them to take genes from any animal, plant, bacteria, or virus and transfer the genes into another organism. Genetic engineering is an unnatural technology with unprecedented power to "engineer" the nature of any living organism. The debate over whether genetic engineering is good or bad is raging among the world's scientists. On one side are those who see genetic engineering as a boon to humankind, with the potential to end hunger, improve health, reduce pesticide use, and conserve natural resources. On the other are those who think the speed at which genetic engineering is showing up in laboratories, fields, and kitchens is unethical and unsafe.
|
