Human Variation and Race
1.
High levels of solar radiation negatively impact
the survival of humans by disturbing homeostasis. This can occur with either
too much exposure to the sun or too little. Our body needs Vitamin D from the
sun in order to function properly. Without Vitamin D our body can experience weakness
in our immunity, bones, teeth, and muscles. Solar radiation provides our body
with the Vitamin D that we need to strengthen our body in all those areas. It
helps restore bone tissue and replaces the old bone with new bone. Also too
much solar radiation can have a negative impact because the overexposure of UV
rays can be absorbed into the cells and turn into skin cancer. It seems were
doomed with it or without it. Solar radiation needs to be absorbed in
moderation to receive the full benefits; overexposure can lead to a disruption
in homeostasis and can turn into a very dangerous thing if not monitored.
2.
Cultural
Adaption: One form of a cultural adaption that humans have used to adapt to
this stress is by using sunscreen. Just because you wear sunscreen when out in
the sun doesn’t mean your completely safe from its harm. It does help reduce
the amount of UV rays that get absorbed into your skin, but there are some that
can still seep through so it is best to use other forms of adaptions such as
putting an umbrella up at the beach or putting on a t-shirt if directly exposed
to the sun.
Facultative
Adaption: Since UV rays are the strongest in the summer vs. the winter most
people like to lay out and tan by the pool. Even during the winter individuals
will go to the tanning salons and use that as a source to maintain their summer
body glow. This is an example of Facultative Adaption. Melanin increases in
size and number when exposed to ultra violet radiation. This is an example of
altering a phenotypic expression in response to an environmental stress. Now
some people aren’t as lucky, like me most fair skinned people have a hard time
tanning so not only are we altering our phenotypic expressions it can be more
painful and harmful than for most. We are more likely to burn and peel and be
at risk for skin cancer.
Developmental
Adaption: Individuals who are exposed to the sun for longer periods of time
are at a higher risk of developing skin cancer ( melanoma). The UV rays lead to an increased production of
melanin. These individuals over time will develop a darker skin tone and are
more likely to develop skin cancer. Not only does over exposer of solar
radiation cause developmental adaption but so does being underexposed to UV
Rays. People who live in northern latitudes where there is less solar radiation
are better off at protecting their skin, but for those with darker skin this becomes
a serious risk. Reduced solar radiation leads to a lack of Vitamin D which can
lead to life threatening conditions such as rickets disease or osteoporosis.
This can have a lasting effect, for instance women who had low levels of
Vitamin D for long amounts of time are at risk of having a normal delivery due
to the deformities of the pelvic. It is interesting because research shows that
is common for dark skinned people to be Vitamin D deficient because of lacking melanin
to protect their skin, but even for myself, as white as you can get am severely
Vitamin D deficient, I take 2,000 mg. I notice without it my bones hurt and
crack a lot and I constantly feel tired. It just goes to show how important it
really is!
Short
Term: I don’t know If we have a short term adaption to solar radiation.
With too much sun we can either increase our risk of cancer because of burning
and overexposure to UV Rays, or with under exposure we lack Vitamin D which
provides our body with what it needs and without it can lead to permanent life
altering conditions such as heart disease or bone diseases.
3.
I think it is important to study the benefits of
human variation from this perspective because information from these
explorations can help us in finding new ways to defend ourselves against the
negative impacts of solar radiation or help us benefit from getting more of the
sun. It is helpful to study environments where people don’t receive as much sun
because we can study the effects the lack of Vitamin D and Melanin can have on
them, such as bone diseases or affecting the way they have children. We are
able to understand better how we can help those who need more Vitamin D. It is also beneficial to study those environments
where the sun is extremely powerful so we can see how the intake of too much
Vitamin D can lead to life threatening conditions such as cancer. Looking at
these different environments allows us to learn to intake the sun in a healthy
way.
4.
By using race to better understand the variation
of adaptions of solar radiation, we are able to discover how specific environments
are better suited for the exposure of the sun, and which environments are not.
I think the study of environmental influences on adaptions is a better way to
understand human variation than by the use of race because we have a better
understanding of how people adapted to their own environments. For example I think
sometimes people might have the misconception that races with darker skin
probably get the most Vitamin D because they get a lot of sun, when in at times where their environment is lacking solar radiation they develop a higher risk of being deficient not because of their skin color
but because of their environment. I know for me this
was an eye opener in becoming more understanding of how our environment affects
us in a great way.

