The following is a post dedicated to the exemplary work of my students in Anth 102: Introduction to Physical Anthropology. They were tasked with explaining how race is not a biologically supportable concept and instead is a socially constructed one. Please take the time to read these students' work and provide them your appreciation for their hard work.
By: James Odoan
Based on
physical differences, primarily visual, people have been conditioned to viewing
human “races” as containing inherently separate divisions, with an emphasis on
the tones of our skin as a measurement of intellect. This paper will focus on
the physical variation of skin color as a geographical trait that has developed
and evolved as humans have migrated out of the higher temperature regions into
territories where there would be less essential direct sunlight. This paper
will also focus on the biology and health risks that are linked to sunlight and
skin variations and why skin color is relevant to the regions in which we live.
To understand
the fundamentals of skin color and the many variations that exist, first we
must explore the science involved, explaining why we have skin color to begin
with. Correlating closely with the sun’s ultraviolet (UV) rays and geographical
location, variations in skin color are adaptive traits. Anthropologists agree
that as early Hominin began settling in regions with higher temperatures, being
a species that was mostly covered in hair, “these Hominins lived in hot
equatorial environments and had to cope with external heat loads in addition to
those generated by elevated metabolism” (Joblonski 2015), would have found it
increasingly difficult to evaporate sweat, eventually resulting in the loss of
functional body hair, “the loss of body hair left the surface of the skin
increasingly vulnerable to a battery of environmental assaults” (Jablonski
2015). The good thing about the loss of body hair, was that it would lead to
the increased production of sweat glands allowing for easy evaporation of
sweat, and thereby cooling the body more efficiently. On the other hand, one
problem with having less hair, is exposure to the Sun’s harmful UV rays. UV
rays, which are broken in to two types, UVA, (long wave), and UVB, (short wave),
have been known for causing serious medical conditions. “By damaging the skins
cellular DNA, Excessive UV radiation produces mutations that can lead to skin
cancer” (Epstein, Wang 2015). Medical science has shown how dark and light skin
tones have a different reflective value, or in short, the amount of physical
light that reflects off of the surface of the skin. The only solution to
protect ourselves from the harmful UV rays was for our bodies to develop more Melanocytes,
which are melanin producing cells, ”the basic features of these cells are the
ability to produce Melanin” (Cichorek, Wuchulska, Staziewicz, Tymiska 2013), which
would produce the amount of Melanin that is necessary to turn skin dark,
protecting itself from damaging radiation from the sun.
This new darker
skin would allow for enough Vitamin D to absorb adequate amounts of calcium
needed for strong bones. Lack of Vitamin D can be the cause of many medical
conditions “Mounting evidence suggests that Vitamin D deficiency could be
linked to several chronic diseases, including cardiovascular disease and cancer”
(Forrest 2011). Early humans that were
located primarily around the equator were developing darker skin to protect
themselves from harmful radiation that could cause deadly melanomas (skin
cancers). Being a primary source of Vitamin D, the direct sunlight that was at
the equator was more than people of that region needed. “Pigmentation reduces Vitamin
D production in the skin” (Harris 2015). A process idyllic for humans residing
in areas of direct sunlight, this would be ideal if humans were to isolate
themselves to this specific location, but this would not be the case.
At some point in
history human beings began to migrate north into new regions where sunlight
would not be as direct as at the equator, resulting in much cooler conditions.
“In ancient Africa, melanin acted as a natural sunscreen to protect people from
the dangers while still allowing the benefits of Vitamin D synthesis from the
sun” (King 2012). Ultra Violet rays being much lower in the north “the adaptive
sunscreen of melanin” (King 2012), or dark skin, would prove to be a
disadvantage resulting in the evolution of light pigmented skin. This light
skin along with plenty of sunlight would be efficient in synthesizing Vitamin
D, preventing acquired medical conditions that result from Vitamin D
deficiency, such as dental problems and Rickets, a bowing in the large Femur
bones in the legs “Characteristic skeletal deformities are bowed legs”
(Mestrovic 2015). There are many medical conditions that can be caused and
prevented depending on the amount of pigment in our skin.
Pigment in our skin has proved to be capable
of provoking what could be considered the worst of humankind’s deliberations of
one another, and the evolution of the concept of measuring people’s
intelligence, and classification, by the level of pigment in their skin. Which,
by the way, would pave a trail of unfortunate events. The classification of
humans by the color of their skin can be traced as far back as the ancient
Egyptians. ”Ancient Egyptian wall paintings show individuals with different
skin color” (Scupin 2013). A long history of the ethnocentric behavior would
lead to the terrible atrocities of the American slave trade, anthropometry, and
the eugenics movement, to name just a few. As simple a thing such as the shade
for which our skin is, appears to have begun a domino effect of tragedies that
would pepper Americas history. I wonder, if this is what is meant by the
statement, “Correlation does not imply Causation”, it can’t be just a
coincidence that dark skin would evolve to become light skin through natural
selection, a force that works to the health benefit of humans, only for light
skinned people to eventually devise a plan, and through eugenics, attempt an
elimination of dark skinned people. This is a troubling thought. “No person or
group can be the measure of humanity. All people—in every part of the world in
all our cultural, linguistic, and biologic diversity—are equally human” (NAS
1997), We all have our weaknesses’ as well as our strengths, no better, no
worse.
The focus of
this paper is to try and understand what it is that has been the leading cause
for the need of pigment in our skin. While also touching on the dangers of
Ultra Violet rays, and our body’s requirement for Vitamin D, the evolution of
skin color in humans has been a process of natural selection, defending us from
harmful radiation or allowing for enough Vitamin D for strong bones. As well as
expressing the perils that dark skinned people have endured given the amount of
pigment is in their skin. This paper is not intended to be a systematic chain
of events, but only to try and create an understanding of how people have
evolved by tracing the evolution of skin tone.
Works Cited
Jablonski,
Nina G. "Human Skin Pigmentation as an example of Adaptive
Evolution."
Department of Anthropology, Pennsilvania State
University, n.d. Web. 5 Oct. 2015.
<http://www.amphilsoc.org/sites/default/files/proceedings/Jablonski1561.pdf>.
Epstein,
John H., and Stephen Q. Wang. "Understanding UVA and UVB." Skin
Cancer
Foundation, 2015. Web. 6 Oct. 2015.
<http://www.skincancer.org/prevention/uva-and-
uvb/understanding-uva- and-uvb>
.Cichorek,
Miraslawa, Malgorzata Wuchulska, Aneta Staziewicz, and Agata Tyminska.
"Skin Melanocytes: biology and
development." Advances in Dermatology, 2 Feb.2013.Web.6Oct.2015.<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3834696/>.
Forest, Kimberly.
"Prevalene and Correlates of Vitamin D Deficiency." pubmed.gov..
U.S.
National Library of Medicine, 31 Jan. 2011.
Web. 6 Oct. 2015.
<http://www.ncbi.nlm.nih.gov/pubmed/21310306>.
Harris, Susan S.
"Vitamin D and African Americans." American Society for Nutrition,
2006. Web. 6 Oct. 2015.
<http://jn.nutrition.org/content/136/4/1126.full>.
King,
Barbara J. "For Summers First Day, The Science of Skin Color." 13.7
Cosmos & Culture,
21 June2012.
Web. 6 Oct. 2015.<http://www.npr.org/sections/13.7/2012/06/21/155297960/for-
summers-first-full-day-the-science-of-skin-color-and-vitamin-d>.
"Evaluating
Human Genetic Diversity ." National Academy Of Sciences, 1997. Web. 4 Oct.
2015.
<http://www.ncbi.nlm.nih.gov/books/NBK100423/>.11
Mestrovic, MD, PhD, Dr. Tomislav.
"Rickets Symptoms." news-medical.net. News Medical Life
Science & Medicine, 28 June 2015. Web. 11
Oct. 2015. <http://www.news-
medical.net/health/Rickets-Symptoms.aspx>.
Scupin, Raymond. Race and Ethnicity.
second ed. Saddle River: Pearson, 2003. 12. Print.
By Mark Scheuermann
Throughout
time skin color has not been properly addressed and instead has been used to
discriminate, enslave, and even murder entire populations. Only recently in human history have we been
able to discover that skin color is not a social ranking but rather a variation
of those of another skin color. Complex
biological processes take place in the skin and can eventually change the skin
color in a population. Thus, certain
colors are better adapted to certain parts of the world. Thanks to this type of information, we have
learned that “correlation does not imply causation” when it comes to skin color
in many ways. This positive change of perspective
on skin color is due in large part to recent research in human variation and
polygenic traits.
We
will begin with the complex biological processes that take place above and beneath
the skin. Cells on the surface of skin,
known as melanocytes, produce melanin as a response to sunlight exposure
(Jurmain et al. 415). Melanin is
involved in a few aspects of physical appearance, including eye color, but none
more significant than skin color. Melanin
acts as a sunblock for the skin as it absorbs ultraviolet rays from the sun
that pose a potential threat in the form of skin cancer (415). The more melanin, the darker the skin
color. This helps us to understand why
populations that originated around the equator have very dark skin. As hominins began to migrate north to what is
now Europe, skin lightened. At first, this puzzled scientists as cloudy skies
and colder conditions did not explain why darker skin faded in these areas so
quickly. The answer is likely Vitamin D
production as it is very important toward many bodily functions. Chapter fifteen explains: “…the body’s
primary source of vitamin D is its own ability to synthesize it through the
interaction of UV radiation… Therefore adequate exposure to sunlight is
essential to normal bone growth.” (418).
Thanks to important research it has become clear why modern humans
display such a variety of skin color across the globe.
Along
with melanin and Vitamin D production, polygenic traits are a huge supporting
reason as to why “race” is no longer acceptable in the scientific
community. Many traits displayed by
different humans are not so black and white.
The shape of the head, eye color, size of the nose, and many other
traits are determined by multiple genes, making them polygenic traits. This makes it extremely difficult to draw a
line between different “races” as those of a similar background are likely to
display a great amount of variation (394).
Again, much research has gone into studying the reason for different
tones of skin and the presence of polygenic characteristics is huge when it
comes to the biology behind skin color.
Taking
in the information on skin variation helps us to understand why different skin
colors are better suited to certain areas of the world. Hominins evolved in Africa, but only theories
exist on whether or not they had dark skin to begin with. For example, “Jablonski…has proposed that the
earliest hominins may have had light skin covered with dark hair, as seen in
chimpanzees and gorillas.” (417). As
hominins evolved (and simultaneously evolved outside of Africa in Eurasia) and
began to lose body hair, darker skin became favored. In northern Europe, the lack of radiation
exposure allowed skin color to lighten up for the important process of Vitamin
D production. It is interesting to
consider the routes these hominins took as they made their way out of
Africa. A population could suddenly
decide to change direction and have no idea that they had likely altered the
skin color of their future generations. Additionally,
they subjected themselves to different forms of environmental pressures as they
headed into the unknown. The good that
came out of it included increased variation (from living in extreme conditions)
and eventually, thanks to natural selection, the best skin color suited to
their new environment.
Finally,
we have learned that correlation does not imply causation with human skin
variation. Both Carolus Linnaeus and
Johann Friedrich Blumenbach placed humans into categories based not only on
skin color but also characteristics of those of a certain color (390). Today most people would consider this type of
perspective both ignorant and arrogant.
Ignorant for the lack of knowledge that we have today and arrogant for
describing their own skin color as having the most favorable characteristics. For instance, not all white-skinned people
are gentle, while certainly not all black-skinned people are compulsive as
Linnaeus believed. Unfortunately the
belief that darker-skinned individuals were inferior to the European race led
to a fear of a weakened society caused by the inferiors (391). This idea was supported by Francis Galton,
cousin of Charles Darwin, who “…wrote and lectured on the necessity of “race
improvement” and suggested government regulation of marriage and family size,
an approach called eugenics.” (391).
This concept that one race can be superior to another also led to people
feeling justification with their ownership of slaves. In our current society this would be
unacceptable and it all traces back to biological discoveries that have shown
us why different skin colors exist.
In
class, the anthropometric measurements lab further proved the variation amongst
people with similar ethnic backgrounds. Measurements
dealing with cranial capacity and height showed that Caucasians can have a
range of cranium sizes and heights. Such
experiments demonstrate how lines are hard to draw between so-called races
since different characteristics that once defined race are polygenic
(395). The characteristics are now
nearly impossible to categorize based on skin color alone since they are
polygenic and hinge on multiple genes.
Discrimination
based on skin color is still prevalent today, but scientific discoveries have
led us to believe that skin color is simply a display of human variation rather
than a definitive race. Discoveries on
melanin production, ultraviolet radiation and its effects, Vitamin D and its benefits,
migration routes, and polygenic traits have given the world the necessary
information to no longer see those of a different color as being of a different
race. No longer does correlation imply
causation on the subject in the scientific world. The average citizen may still need further
improvement on perspective when it comes to skin color but we are well on our
way with more insight on our variation becoming available each day.
Works Cited
Jurmain, Robert, Kilgore, Lynn,
Trevathan, Wenda, Ciochon, Russell L. Introduction
to Physical
Anthropology. Belmont,
California: Wadsworth, 2014. Print.
