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In chapter 9 we looked at the ways in which microorganisms duplicate,
exchange, and use their genetic information. In scientific
parlance this is called basic science, because no product or application
is directly derived from it. Human beings being what they are,
however, it is never long before basic knowledge is used to derive applied
science, or useful products and applications that owe their invention
to the basic research that preceded them. As an example, basic
science into the workings of the electron has led to the development of
television, computers, and cell phones. None of these staples of modern
life were envisioned when early physicists were deciphering the nature
of subatomic particles, but without the knowledge of how electrons
worked, our ability to harness them for our own uses would never have
materialized.
The same scenario can be seen with regard to genetics. The
knowledge of how DNA was manipulated within the cell to carry out the
goals of a microbe allowed scientists to utilize these processes to accomplish
goals more to the liking of human beings. Contrary to being a
new idea, the methods of genetic manipulation we will review are simply
more efficient ways of accomplishing goals that humans have had
for thousands of years.
Examples of human goals that have been more efficiently attained
through the use of modern genetic technologies can be seen in
each of these scenarios: -
A farmer mates his two largest pigs in the hopes of producing
larger offspring. Unfortunately he quite often ends up with small or
unhealthy animals due to other genes that are transferred during
mating. Genetic manipulation allows for the transfer of specific
genes, so that only advantageous traits are selected.
-
Courts have, for thousands of years, relied on a description of a
person's phenotype (eye color, hair color, etc.) as a means of
identification. By remembering that a phenotype is the product of a
particular sequence of DNA, you can quickly see how looking at
someone's DNA (perhaps from a drop of blood) gives a clue as to
his or her identification.
-
Lastly, many diseases are the result of a missing or dysfunctional
protein, and we have generally treated the disease by replacing
the protein as best we can, generally resulting in only temporary
relief and limited success. Examples include insulin-dependent
diabetes, adenosine deaminase deficiency, and blood clotting
disorders. Genetic engineering offers the promise that someday
soon fixing the underlying mutation responsible for the lack of a
particular protein can treat these diseases far more successfully
than we've been able to in the past.
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