1. High
levels of solar radiation is an environmental stressor which negatively impacts
the survival of humans by disturbing homeostasis; radiation occurs from solar
storms in the universe. This produces UVA rays which penetrate through human
skin going through the epidermis layer and causing defects in the human
cells. Then there is the UVB rays that
goes through our skin and that cause’s cell deformation, skin cancer, and this
genetic level disturbs homeostasis and is harmful to our survival.
2. Short term
adaptation for solar radiation is hard to say since there isn’t really one
other than stay out of the sun.
Facultative adaptation to
protect us from the harmful UVB radiation waves is skin tanning and tanning
happens when exposure to sunlight triggers a protective mechanism through
increased melanin production in the epidermis layer. The more
time spend in the sun during the summer months with the warmer weather, it is
common to see people of both fair and dark skin have a darker complexion.
Developmental is in populations that
have been exposed to a large amount of solar radiation and so therefore their
skin has become dark to help protect themselves for an over absorption of UV
rays. People who live in the Savannahs
of Africa or tropical places have dark skin and are able to withstand higher
levels of solar radiation exposure. You
can see the proven correlation between people’s skin color and living
environments.
Cultural adaptation to the harmful UVA and UVB
rays are clothing, shelter, hats, sunscreen lotions and
sprays. Clothing and shelter made it possible to limit exposure to
the sun’s radiation and therefore reduced the need for such high levels of
melanin production. Migrating to other environments such as forested
areas also reduced our time in the sun and see the change in skin pigmentation
with the lighter skinned populations possessing more of the northern
geographical regions and darker skinned populations possessing more central and
southern regions closest to the equator.
Now people of all skin pigments now populate all regions of the globe
and instead of migrate northward if you are light skinned, the invention of
sunscreen lotion can protect you for longer periods of time in the sun.
3. The
benefits of studying human variation is to understand the changes of various
sample populations over time, human adaptation and to evaluate and see the
environmental stressors. For example, by studying UV radiation
we discovered it causes skin cancer or by studying skin cancer we found that it
is caused by UV rays. Either way we need
to determine what levels are acceptable to the human body and what amount is
needed to survive in order for the body to produce the proper levels of vitamin
D.
4. I
would use race only to classify geographic groups of people who have the same
or similar set of adaptations to the same environment and this will help with
understanding their ancestral traits and able to keep track of when population
may have migrated due to environmental stresses. Studying the environmental
influences of a group of people over long periods of time you see patterns
which evolved as adaptations to those outside stressors and some adaptations
like being born with lighter or darker skin become permanent, while others will
remain until the stressor has been removed such as tanning during the summer
with increased sun exposure. I believe that being able to study the human
species is a great tool to help people overcome racism and see more of the ways
we are alike than the ways in which we differ and that certain traits have been
developed due to a change in the environmental influences.
