1. Select only ONE of the following environmental stresses:
(a) heat, (b) high levels of solar
radiation, (c) cold, or (d) high altitude. Discuss
specifically how this environmental stress
negatively impacts the survival of humans by disturbing
homeostasis. (5 pts)
The environmental stress I chose was High levels of solar
radiation which has a negative impact on Humans by affecting and disturbing
homeostasis. UVA (Ultraviolet Radiation) affects homeostasis because it has the
power to penetrate the human’s outer layer of skin which is called the
epidermis all the way to the inner layer called the dermis. The other type of radiation
is UVB radiation, but this type of radiation only penetrates the Epidermis. Our
body does get some type of positive response in exposer to this type of radiation
and that is exposure to UVB waves is it creates Vitamin D. One of the biggest
stresses this radiation causes is the on the short term spectrum and that would
be Sun burn from too much exposure to the sun. Long term effects would be that
over exposure of these UV radiation would be types of skin cancer.
2. Identify 4 ways in which humans have adapted to this
stress, choosing one specific adaptation
From each of the different types of adaptations listed above
(short term, facultative,
Developmental and cultural). Include images of the
adaptations. (5 pts each/ 20 pts total)
Short term= I don’t really think that humans have
adapted in a way to high levels of solar radiation, but one could be sweat or
flushed skin to let us know that we have been in direct sunlight to long, and
once you remove yourself from the situation and environment our bodies will
transition back to normal.
Facultative= Over exposure to UVA radiation causes
some humans phenotype to change and their epidermis to become darker because of
an increased melanin production in the top layer of the skin, we call this
tanning. The transition period back to normal is a longer period than the short
term responses, and most humans purposely expose themselves to the sun to get
this response called tanning.
Developmental= Developmental
changes are found in different types of environments. Through evolution humans
who have been in warmer environments have had changed to their DNA making their
skin darker like people from Africa. These traits you are born with and will
not change over your life time.
Cultural = humans are very unique in creating tools
to help deal with these environmental stresses to help us survive. I think I great
one to deal with High amounts of exposure to radiation would be the creation of
Sunblock which helps protect the skin and minimize the amount of UVA that
penetrates the Skin. We also created hats and Gazebos that help create shade so
we can increase the amount of time we spend out in the sun.
3. What are the benefits of studying human variation from
this perspective across environmental
clines? Can information from explorations like this be
useful to help us in any way? Offer one
example of how this information can be used in a productive
way. (5 pts)
The studying of human variation from this perspective can be
very beneficial. If we can determine how long it takes for the DNA to be
changed over generations, we could possibly determine the migratory pattern and
get closer to the actual timeframe of our ancestors. It takes over many years to see change in our
DNA to change our Phenotypes of skin color, but if we could determine if the
sun exposure is really the cause of change then skin color would not be the
factor of naming somebody’s race as I always believed.
4. How would you use race to understand the variation of the
adaptations you listed in #2? Explain
why the study of environmental influences on adaptations is
a better way to understand human
variation than by the use of race. (10 pts)
The term race is usually dependent upon someone’s skin
color, but as I listed above if they studied the human variation to sun
exposure and the color of their skin, then race would be looked at as more than
just skin color because your skin color is just the result of your ancestors having
a certain amount of sun exposure over many generations.
Great detailed post! Your answer for number 4 is very thought-provoking as though we do categorize race based on skin tone and that usually branches on origins, but someone whose ancestors are from Croatia might have abnormally dark skin for a Croatian dependent on how much time his ancestors stayed out in the sun. The validation of how we define race currently might be jeopardized by this thought of how much sun exposure effects it. Good job!
ReplyDeleteVery informative. I'm wondering if humans have created so much negative information regarding the negative effects of the UVA/UVB radiation, they have neglected the fact that we need those rays also for the vitamin D causing Calcium to be absorbed. Media has assisted in presenting the negative so much, we have forgotten about the positives of those rays as well.
ReplyDeleteGreat explanation on solar radiation stress, including the note that we do get something positive (Vit D) from that radiation.
ReplyDeleteCorrect, humans have no short term response to solar radiation, which is why this such a dangerous stress.
Great identification and description of the other three adaptations to solar radiation.
Good discussion on the way we can productively use the information we gain from this adaptive approach.
The concept of race doesn't change because we better understand human variation. Race is a social construct, not a biological one. Can we use a subjective social concept like race to objectively understand biological traits? Since each culture has it's own definitions of race, whose set of definitions would we use?
Great post! I really enjoyed reading on what you had to say on this topic because I picked the same one however. I think its cool how through blogger we get to see everyone's thoughts on a certain subject.
ReplyDeleteI think you did a great job on the post. I was a little confused on question two, I thought we were only supposed to choose one specific adaptation, but I could be wrong. You also forgot to add your photos of the adaptations. I specifically enjoyed the details that you provided on Solar Radiation. It helpful for those who do not understand the difference. Good job!
ReplyDeleteI think you did a great job on the post. I was a little confused on question two, I thought we were only supposed to choose one specific adaptation, but I could be wrong. You also forgot to add your photos of the adaptations. I specifically enjoyed the details that you provided on Solar Radiation. It helpful for those who do not understand the difference. Good job!
ReplyDeletethank you
ReplyDelete