Ephefany Tiongco
SLOT C
Human-influenced Natural Selection
Case Study #1
1.) Using the example of the peppered moth, explain how natural selection and
differentiated mortality have changed the makeup of the moth population.
The species of the night-flying peppered moth is a prime example of natural selection and due to its
light-gray colour, it no longer works as a camouflage in the dark forest as soot slowly covered the bark of trees in
industrial areas making them vulnerable to insect eating birds. Though, the black moths and their dark colour
which was caused by a rare genetic mutation in the DNA excelled in the dark forests. A major decrease in the
peppered moth’s population from the lack of reproduction which caused fewer offspring to inherit the genetics led
the light coloured variants to be eaten. With the differentiated mortality, it further evolved since the environment
also changed for the black moths to have better adaptation.
Case Study #2
2.) List three ways introducing the Nile perch to Lake Victoria had negative impacts on the
ecosystem of the lake.
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The Nile Perch ate fish that fed on algae. The fish who ate the algae constantly kept the lake clear.
Although, the algae became uncontrollably thick resulting in overwhelming thickness therefore winding
up dead and rotten at the very bottom of the lake. In today’s time, there is now no oxygen to be found in
the water below a depth of approximately 100ft due to sunlight fading out at about 104 ft of depth where
the tilapia can hide within.
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When the fisherman turned to the Nile Perch, sun drying was no longer available. The Nile perch were
too large and too greasy in order to sun dry. Because of this, they preserved them by using wood to
smoke which led to deforestation of the shoreline around Lake Victoria as well as soil erosion.
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The voracious Nile Perch would only eat its own kind (fish), and grow to weigh hundreds of pounds.
They ate the fish that fishermen depended on for food. The tilapia had a drastic decrease in their
population because of its predator, disallowing fishermen to hunt them again.
3.) Using the example of Lake Victoria, explain why the Canadian government is so
against the Garrison Diversion Project in North Dakota.
The Canadian government is against the Garrison Diversion Project located in North Dakota because
the project may negatively affect not only our environment, but also our economy. According to the article, these
projects may potentially cause “catastrophic, costly and irreversible damage” to the Canadian waters and have
the potential to violate the 1009 Boundary Waters Treaty (BWT).
4.) Explain why using antibiotics in conditions when their use is not really needed and
can lead to the production of antibiotic resistant bacterial strains.
Unnecessary uses of antibiotics usually when not prescribed to a patient; can lead to improper and
dangerous usage. Patients who do not succeed in treating themselves entirely will not properly cure the
disease and instead create a potential health hazard by promoting the growth of the antibiotic resistant
bacterial strains that may lead to hard-to-treat disorders.Patients who suffer from minor conditions such
as a cold or a mild cough should avoid demanding antibiotics so that they can assess which pathogen
they would need to kill, assuring that they find the correct antibiotics to decrease any resistant strains.
5.) Use the concept of natural selection to explain how using antibacterial soaps and
disinfectants works to actually increase the production of hardier bacterial strains.
Antibacterial soaps and disinfectants are commonly used to kill bacteria but because we frequently use
them, they promote new strains of bacteria which are more resistant to these antibacterial solutions.
Natural selection takes place as these resistant microbes have been with other bacterias but once the
weaker strands have died off due to the given chemicals, the resistant strains grow to produce.
6.) List 2 things the average person can do to help reduce the production of antibiotic
resistant bacterial strains.
To help reduce the production of antibiotic resistant bacterial strains an average person can simply use standard
soap or detergent. Regular alcohol, soap, bleach and hydrogen peroxide in standard chemicals tend to decrease
the potential and harmful bacteria. Cleaning is essential but over cleaning can lead to promoting new growth of
resistant bacteria strains. Everyday items we use for cooking should be cleaned thoroughly after in contact with
raw food to avoid the growth of bacteria. As we use standard soap on these items, it will allow bacteria to die but
also will not be long enough to allow resistant strains to grow.
7.) What is unnatural selection according to this article and what does it cause with
respect to genetic fitness?
According to the article, unnatural selection is when nature is dealing with a controlled environment. The genetic
changes are random, sporadic and are not linked with environmental changes. Weather, environment, disorders do
not affect us because we are able to control our surroundings. A few examples of a controlled environment within
the human species are taking antibiotics for our illness, we can control temperature by using heaters or air
conditioners, using prescription glasses and etc. Unnatural selection decreases and lowers our genetic fitness. This
is produced from genetic defects, mutations and modification in our lives. In order to further improve our rate of
survival, we create and evolve things that are essential in our lives, but our genetic load in defective genes still
passes on.
8.) What is genetic loading?
Genetic loading is harboring defective and genetic mutations in a population.
9.) What is eugenics? Give an example of its application.
The term eugenics is the capability of improving humanity’s race. Selectively reproducing desirable
traits will improve human’s population. One example from Plato is that reproducing with better
specimens of humans should be encouraged and the worst should be limited.
10.) What is euthenics? Give an example of its application?
Euthenics describes the tools of our highly technical environment to lessen the impact of our genetic
load. An example for euthenics is the use of drugs for the benefit of controlling our genetic disease,
insulin for diabetes and glasses for vision.