Environmental Engineering Reference
In-Depth Information
Another technique that became frequently used during the Green Revolution is
monoculture,
in which a field
is planted with only one crop. Generally, monoculture makes planting and harvesting more efficient and, thus,
more cost-effective. However, since a monoculture crop shares genetic makeup, the crop is at increased risk of
decimation by one type of pathogen or pest. Also, monoculture allows fewer ecological niches, decreasing the
potential for biodiversity. Without increased use of fertilizers, monoculture can deplete the soil of nutrients.
Monoculture also is used in the livestock and aquaculture industries.
Genetic Engineering and Crop Production
Changing segments of an organism's DNA is called
genetic engineering
or
genetic modification,
and organ-
isms that are altered are called
genetically modified organisms.
In the process of genetic modification, genes
from an organism with a desired trait are harvested and spliced into the DNA of an existing organism. Ultim-
ately, the combination creates the desired traits (for example, increased growth rate, disease resistance, or size).
The result of artificially transferring genetic material is known as a
transgenic organism.
Historically, the
technique used to introduce desired traits in existing crops or livestock was selective breeding, but genetic
modification differs in its altering of an organism's DNA; it might mix genes from different species with little
or no similarities.
Here are some examples of genetically modified crops:
•
Golden rice:
Contains vitamin A, a missing nutrient in many developing countries
•
Ice-minus strawberries:
Frost resistant
•
Bt corn and cotton:
Contain insecticide, removing the need to spray chemicals
•
Long-lasting tomatoes:
Remain fresh longer
Generally, both sides of the genetic modification admit that genetically modified foods are entrenched in our
food supply, for better or worse. Still, genetic engineering is a much-debated and highly emotional topic, with
the basic points on both sides as follows.
Advantages and Disadvantages of Genetic Modification
Pros of Genetic Modification
Cons of Genetic Modification
The ability to feed more people with less en-
ergy, making farming more efficient
Unknown long-term effects on human health
The capability for foods to stay fresh longer,
allowing them to be transported farther and
have a longer shelf life
The ability for pests and weeds to grow resistance to the seeds
containing built-in pesticides and herbicides, ultimately creating
the need for more powerful products
The possibility to create foods resistant to
weather extremes, which reduces the loss to
the farmer and creates more consistent
products and markets
The destruction of native, non-genetically-modified crops
The potential to develop foods containing nu-
trients missing in a local culture
The possibility of exacerbating allergies in people by creating
either more products with the same allergen or a new allergen
The potential for improvements in medicine
through development of new products
The unknowns of a new technology
The potential for seeds with built-in resist-
ance to pests and weeds
The belief that, ethically, altering the food supply is not right
