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Survival of the Sickest: Chapter 3

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Manisha Rattu

on 27 August 2014

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Transcript of Survival of the Sickest: Chapter 3

Why do we need Vitamin D?
Survival of the Sickest: Chapter 3
CHO-CHO for Cholesterol

Cholesterol is necessary to make and maintain cell membranes.
Vitamin D is made from converting cholesterol.
It helps the brain to send messages and strengthens the immune system to protect against cancer and other diseases.
It is important component for the production of hormones like testosterone and estrogen.
Lastly, cholesterol is necessary for the production of vitamin D.

Why do we need Cholesterol?
Folate is an important part of the cell growth system, as it helps the body to replicate DNA when cells divide.
A lack of folic acid during pregnancy can cause physical deformities to the fetus.
Since folate helps to produce red blood cells, a lack of folate can lead to anemia.

Why do we need Folic Acid?
What is the connection between tanning beds and birth defects?
Sight allows one to observe light and tell the the body to produce melanin, which is a pigment that absorbs light.
It is because of sight that people have been able to expose themselves to the Sun and simply become darker, not burnt.
With the interference of sunglasses, this message is not sent to the pituitary gland; therefore, the melanin is produced at very low levels, so the skin cannot absorb the sunlight and becomes burned.
Evolution has allowed the body to experience high levels of sunlight; however, human interference is providing a threat which can cause bodies to possibly evolve to signal the gland by other means.
What is the connection between sunglasses and sunburn?
African Americans’ were transported to the US in inhumane conditions, which may have caused them to increase their salt levels to increase survival rates.
Over time, however, as nutrition and health increased, the high salt actually posed a threat as it lead to high hypertension.
Now, this benefit has become a killer for the population and reduces their chances of survival, as opposed to increasing them at the time of the slave trade.

What is the connection betweem hypertension and slave trade?

Once one takes a sip of alcohol, it immediately enters your bloodstream through your stomach and small intestines, where special enzymes go to work.
The Asian flush is caused by certain enzymes that enable tolerance to alcohol.
This variation can be explained by comparing the ways European and Asian civilizations practiced to get clean water.
Europeans used the metabolic process of fermentation, and the resulting alcohol killed microbes when it was mixed with water.
Asians however cleaned their water by boiling it, so they were never under evolutionary pressure to drink alcohol in order to get clean water, resulting in less tolerance to alcohol

What is the connection between Asian flush and drinking water?
Skull shape is affected by the climate in a sense that scientists believe that the shape depends on how much heat must be stored and released in a particular region.
Humans grow bigger brains as the climate they live in gets cooler, as they need to adapt to the more challenging environment, such as fluctuations in the availability of food and the need for fire and clothes for warmth.
What is the connection between skull shape and climate?
Vitamin D is important as it ensures the growth of healthy bones in children and maintains healthy bones in adults.
It makes sure that our body has a sufficient amount of calcium and phosphorus.
Additionally, some new research is discovering that it is also important for the proper function of the heart, nervous system, the clotting process, and the immune system.
In adults, vitamin D deficiency can lead to osteoporosis and children can develop rickets, which results in improper bone growth and deformity.
A number of other diseases ranging from cancer to mental illnesses have been linked to vitamin D deficiency.

Without a sufficient amount of folic acid within the body, cell growth is hindered.
In pregnant women, this issue is of greater concern since cells are rapidly growing to develop the fetus.
Exposure to ultraviolet light destroys folic acid; therefore, women who were pregnant and using tanning beds tended to give birth to children with defects because there was not enough folic acid present to ensure the child’s healthy development. Folic acid is needed to carry out functions that can lead to better survival rates, which in turn leads to a stronger generation that can be more equipped to survive and reproduce, as well as evolve.
What is the connection between body hair and malaria?
Dense and thick body hair, especially on the forearms and legs, are regarded as a natural defense to ward off mosquitoes that could potentially carry malaria.
What’s so fishy about the Inuits’ skin color?
It is generally considered that the skin color of the people native to a region is related to the amount of sunlight that the region receives.
This explains why people in Africa developed a darker skin color and why people in Europe developed a lighter skin tone.
This allows them to change their melanin concentration in order for the body to make better use of the sun that they receive. People with darker skin let less sunlight affect them and made use of the little that was allow through.
On the other hand those with white skin we're adapt to allow much of the light they received through since they lived in generally cloudy area.
The Inuits are the exception to this consensus. They do not follow this rule. They are a group of people who live in a cold dark area but have a very dark skin tone.
Explain the good and the bad of ApoE4.

ApoE4 ensures that the amount of cholesterol is abundant throughout the body, which is beneficial to dark skinned people.
With enough amount of cholesterol to convert, dark-skinned people can easily use direct sunlight that they encounter to create Vitamin D.
Light- skinned people also encounter such a problem. Due to the lack of sunlight up North, ApoE4 provides cholesterol to create Vitamin D.
However, with so much cholesterol filling the body problems can also occur.
The extra cholesterol created a greater risk for heart disease and stroke.

If certain types of skin characteristics ensure higher survival, then those characteristics will spread, only where needed and
during a person's life span.
Kevyn Herrera
Anita Rani
Simret Sutti
Gurpreet Telwar
Manisha Rattu
Main Ideas:
Humans evolve within a dual relationship, one that both helps and harms.
It only takes about 1000 years for a population's skin color to change, if there is a change in the climate or surrounding environment.
"Evolution exists without a purpose. It is a population's response to the pressures exerted on reproduction by the environment over time."
Cholesterol, folic acid, and Vitamin D are all intertwined to develop the human body.
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