Genetic modification is when an organism containing genetic code
has been altered to obtain a desired characteristic. The earliest examples
of genetic modification/manipulation included the selective breeding of
plants and animals, which has been taking place over the last 10000 years. It has been recorded that early societies like the Romans were using
manipulation or selective breeding for more efficient livestock, and for
better crops[2]. These genetic manipulations have resulted in common
food and animal species that are now genetically different from their
ancestors. Selective breeding works by having a mother and a father with
desired traits, for example a cow that grows bigger than most other cows
is bred with another larger cow. By breeding the two together, the
offspring provided now may grow larger than most cows. The same
process would work when manipulating for things like appearance, intelligence, or athletic ability
[6]. Major advances in the science around genetic modification took
place in the year 1972 by Herbert Boyer and Stanley Cohen, after they
were able to directly transfer DNA (DeoxyriboNucleic Acid) between two
organisms. The first genetically modified animal was a mouse, in 1974 by a
man named Rudolf Jaenisch[7]. One example of genetic modification would
be crops that are resistant to pests/insects, and where the farmer does
not have to use pesticides. Using genetic modification, genes from a
certain bacteria, known as Bacillus thuringiensis, is inserted into the DNA
of the crops
[7]. Once inserted, the genetically modified crop now has the
ability to create toxins, to defend itself from insects, while providing
consumers with pesticide free food to eat. DNA acts like the carrier of
information, and is present in all living organisms. Genes are what make
up DNA, where each gene is responsible for a certain trait for that
organism, ranging from how it acts, looks, and even grows. When all the
genes are put together they form DNA. This is just a small example of the capability of genetic modification. Using genetic modification, scientists have been able to do things like
create vaccines for diseases, make altered food that tastes better and
even cloning animals.
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How Scientists Modify Genes
When Scientists modify genes it is just like copying and pasting
content from a source to a target. According to yourgenome.org,
scientists first locate the gene that they want, from a sample of the
organism. Then, using “Restriction enzymes” they cut out the specific part
of the DNA they want
[11]. In order to cut certain parts of DNA, certain
restriction enzymes are needed. After cutting out the wanted gene, the
scientists then use the same restriction enzymes to cut the DNA of the
organism they want to transfer the gene to. Now, the scientists need a way
of combining the gene with the other DNA. To do this, they use an enzyme
called DNA ligase, which acts like tape[11]. Using this, they can seal the DNA
and the gene together, creating the new Genetically Modified DNA. This
process is the same for both plants and animals alike[8]. GMO Foods
GMO foods have been available for sale since the early 1990’s
[2]. Because of the concept of GMO foods being fairly new, scientists still do
not know what the long term effect of eating or growing genetically
altered food could be[2]. Gregory Jaffe, director of Biotechnology at the
Center For Science in the Public Interest, insists that scientific studies
clearly show that there are no negative effects of eating or growing GMO
foods, and there appears to be no long term effects. In 1994, the first ever
genetically modified food available for public consumption was created, named the “Flavr Savr Tomato”[10]. The Flavr Savr Tomato was created by a
company named Calgene, and it was different from other tomatoes
because it could last much longer on shelves, was more resistant to
rotting, and had a much better taste to it. This genetically modified
tomato would open the path to new and different types of genetically
modified foods. GMO foods offer benefits to producers and consumers. As an example, in comparison to normal foods, GMO foods could stay
fresh from 2-4 weeks longer than a non GMO food. Other benefits of GMO
foods include natural self produced pesticides, faster growing rates, more
flavor and grow in larger amounts
[7]. According to David Zilberman, a UC
Berkeley Agricultural and Environmental economist, GMO foods will be
able to survive and grow in more hostile areas, allowing more food to be
grown at one time. The use of GMO foods has increased the output of
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corn and soy by around 20%-30%. GMO crops have an increased ability to
survive more extreme temperatures, dry or salty land, as well as a higher
tolerance to insects, diseases, and herbicides. Zilberman belevies crop
output will increase because GMO crops will be able to grow on
previously unusable land, including land previously depleted by plant
growth[10]. This will result in more available food for people and lowering
the likelihood of having food shortages. This is very important as the
United Nations estimates that by 2050, we will need to grow 70% more food
than we currently are growing[5]. Today, many common foods we eat have
been genetically modified. This includes things like corn, sugar, soy and
rice.
[10]
Cloning
With advancements in technology over the past 15 years, and
improvement in gene editing, scientists have discovered the ability to
clone mammals, and other organisms
[2]. There are three different types of
artificial cloning, including reproductive cloning, therapeutic cloning, and
gene cloning. Reproductive cloning produces copies of whole animals[2]. Therapeutic cloning is used to produce stem cells and Gene cloning
produces copies of genes or segments of DNA. During reproductive
cloning researchers remove a mature somatic cell (for example a skin
cell) from the animal they wish to copy
[2]. According to the National
Human Genome Research Institute, the researchers then implant the DNA
from the donor animal into an egg which has had its own DNA removed[2]. This process can happen in two different ways. The first method is to
remove the DNA of a somatic doner cell, and implant it into an empty egg
using a needle. The second method is to fuse the donor cell with the
empty egg by using an electrical current
[2]. After one of the two processes
are completed, the egg is allowed to develop into an early stage embryo
and then the egg is transferred into a female host. The first recorded
case of using reproductive cloning to successfully clone a mammal was
on July 5th, 1996, when a sheep named “Dolly” was born[6]. Dolly officially
has three mothers, one who provided the egg, another that was
responsible for providing the DNA, and the third for giving birth to Dolly. Since then, there have been other cloned animals, ranging from rabbits, horses, deer, rats and even fruit flies. But it doesn't stop there. Cloning
can also be used on the medical side of things. An example of this would
be using cloning methods to clone stem cells[11]. Stem cells are created by
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our body for the purpose of healing or expanding things like organs, or
muscles
[10]. The way stem cells work, is by turning itself into a specific cell,
to replace dead or missing cells in the area it is trying to heal/grow. Stem
cells can help replace cells in places like our brains, hearts, lungs, and
many other things. which can be used for repairing damaged tissue or
muscles in our body. By cloning them, we can help people recover from
illnesses or internal injuries. As well, cloning can provide better test
subjects for drugs/medicine, as the reaction to a certain drug may vary
between different test subjects, while as the clones will always have the
same reaction. Although cloning has many advantages, there are some drawbacks. One of these drawbacks are that cloning is not very efficient at creating
healthy clones. An example of this is when Dolly was created, she was the
only clone to be born out of 277 cloned embryos[10]. As well, most clones
end up having defects, or issues with their body. This is most likely caused
due to the science not being perfected as of yet. As well, using cloning, we
can actually clone species that were previously extinct. This could end up
giving us a better perspective of what our history might have looked like. Overall, cloning is heavily regulated by the government, and has many
laws around it, and is used in labs all around the world[10]. C.R.I.S.P.R. There are multiple gene editing tools used by scientists today but