Spotlight on Students: Race Essay

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.