Monday, May 14, 2001
Nature provides for genetic exchanges through natural selection. Humans have long manipulated genetic inheritance through crossbreeding of plants and animals. But, in recent years, scientists have learned how to manipulate the genes themselves moving them at will from one organism to another. In "GMOs, Friends or Foes?" an article in the January-February 2001 "Minnesota Conservation Volunteer," science writer, Mary Hoff, explores what genetically modified organisms (GMOs) mean for Minnesota's environment. She reports that over 250 GMOs with traits such as herbicide tolerance, insect resistance and increased productivity have been released in Minnesota. For example, seeds resistant to glyphosate, a relatively safe weed killer, reduce the need for chemical herbicides and reduce crop injuries that occur with chemical use. Of concern is that GMOs could make herbicides and pesticides less effective by increasing exposure, thus quickening the rate at which weeds and pests develop resistance.
Nevin Young, University of Minnesota plant pathologist, says that genetic technology's greatest benefit is an increase in per-acre productivity, which increases our ability to feed a burgeoning world population. Who can argue against feeding the world?
However, unintended consequences come with GMO use. Hoff cites the deaths of monarch butterfly caterpillars that ate milkweed contaminated with Bacillus thuringiensis (Bt), a microbe that kills the European corn borer. Bt corn roots also release toxins that can remain active in the soil for months. The jury is still out on how these toxins affect soil fauna, groundwater, wetlands and streams.
Hoff writes that transgenic genes may escape and interbreed with organic vegetables and their wild relatives. A wild population of any species consists of individuals whose genetic constitution varies widely. The potential and readiness for change are built into the survival unit. Artificially homogenous populations of man's domestic plants and animals are not well equipped to endure changing conditions.
GMOs tend to promote large-scale monoculture over diversified farming. Add to that the present rate of extinctions and we see a worldwide decrease in diversity and the ability of plants and animals to endure changing conditions, which ultimately threatens life itself.
A recent "Frontline/Nova" special described how GMOs, without our knowledge, have permeated our food sy .....[Read the Rest]