Engineering and Environmental Challenges Technical Symposium on Earth Systems Engineering (2002) / Chapter Skim
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Genetically Modified Organisms: An Ancient Practice on the Cusp
Genetically Modified Organisms: An Ancient Practice on the Cusp
Pages 33-44
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From page 33... ...
Panel ~ Using Biotechnology for the Benefit of Humanity Advances in science Id cnginoodng arc c~c~ng powc-1 tools ~r b~cssing biological acOvity ~r Oman use, but thaw tools cute Asks some Act Ed some pc~ccivod. This peal ~scusscs the inch, ~csponsiblc use of cmcrging biotcchnologics to Edicts globe problems.
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From page 35... ...
During my own undergraduate and graduate studies about 50 years ago, eminent biologists were still choosing up sides as to whether proteins or nucleic acids carried genetic information in chromosomes. Look where we are now!
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From page 36... ...
Other alleles differ not in the gene coding sequence but in the surrounding DNA sequences that regulate the level at which the gene operates, or even whether it operates at all under particular conditions. This sort of modulation of gene activity, which biologists call gene expression, underlies one of the alleles that differentiates modern maize, or corn, from teosinte, corn's wild ancestor of the same species (Zea mays)
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From page 37... ...
Modern molecular techniques emerged about 30 years ago when biologists learned how to manipulate genes precisely through techniques variously called recombinant DNA and cloning. These techniques enabled researchers to make direct changes in DNA structure to accomplish a predetermined purpose.
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From page 38... ...
Consider, for example, Bt corn and Bt cotton, which have been engineered to resist certain insect pests by enabling the plants to produce an insecticidal protein within their own cells. Corn and cotton have also been bred for insect resistance through traditional breeding methods based on natural plant alleles that make plants resistant to some insects.
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From page 39... ...
However, last year two scientific reports showed that milkweed leaves dusted with heavy concentrations of Bt corn pollen are toxic to monarch butterfly larvae in laboratory experiments (Hansen Jesse and Obrycki, 2000; Losey et al., 1999~. This was not surprising, because biologists knew that the Bt toxins were toxic to lepidoptera in general.
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From page 40... ...
Wise policy making will have to be based on the factors that effect monarch mortality (chemical insecticide, the spraying of tons of Bacillus thuringiensis bacteria, the use of genetically modified pollen) as well as crop yields, costs per acre, and local conditions, such as the abundance of monarchs and the timing of larval feeding compared with pollen production.
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From page 41... ...
The French deprived themselves of the nutritious and delicious potato for 200 years after it was brought to Europe from the Andes in the sixteenth century because they believed that potatoes caused leprosy. Tomatoes, another sixteenth century New World contribution to global diets, suffered a similar fate.
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From page 42... ...
be adequately, economically fed without the investments and products of large companies? American farmers, who are usually pragmatic, initially embraced engineered corn, soy, and cotton because they believe they will be economically advantageous.
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From page 43... ...
1999. USDA Report Cites Pesticide Reductions and Yield Increases Associated with Biotech Crops.
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