By Nina Jablonski, Ph.D.
I love evolution. I've been interested in studying evolution almost all of my life. I started collecting fossils when I was a tiny child, and I've always been interested in what life on earth looked like hundreds of thousands and millions of years ago. Understanding the evolution of skin pigmentation helps us to understand, basically, how we can stay healthy in the modern world.
My research relates to behavioral and social science because it involves humans and human decisions, and how human decision-making affects human health. Every day we make decisions about what we eat, what we wear, where we'll go, and what we'll do. And those decisions very much impact the health of our skin, and the skin's mediation of our body health. Because the skin is the major interface between our internal environments and our external environments, the more that we know about the evolution of our own skin the better.
The importance of knowing about the evolution of our skin is especially true in connection with our needs for vitamin D. Vitamin D is critical for the establishment of a healthy skeleton, and basically for the body's ability to absorb calcium from the diet. Even though vitamin D is important, there isn't one single answer to the question of how much sun we should get or how much vitamin D we need. Everyone has different requirements. And one of the things each one of us can do is look at our own ancestry, our own skin pigmentation, and make our own determinations based on these criteria.
When we look at the distribution of skin pigmentation in humans on the earth's surface, we see a conspicuous geographic pattern. Specifically, darkly pigmented people are concentrated close to the equator, and lightly pigmented people are concentrated more toward the poles. This original gradient of skin pigmentation has been disrupted by human movements that have been increasingly long distance and rapid in the last five hundred to a thousand years. This means that we have short-term and long-term displacements of people: people are living, working, and vacationing often long distances from where their ancestors first evolved. And this has tremendous consequences for our skin's health, and for our biology in general.
The history of skin pigmentation, and the perception of pigmentation, is fascinating and complex.
The history of skin pigmentation, and the perception of pigmentation, is fascinating and complex. When humans first started rapidly moving long distances, especially during the so-called era of exploration in the 1400s and 1500s, they started coming into contact with people who looked quite different from one another, and this created a real problem for some. People on both sides of a skin-color divide would look at one another with disbelief, concern, and consternation. Given the geo-politics of the time, Europeans had more cultural wherewithal to be able to write about these phenomena and pass judgment. Western-dominated civilizations today are still influenced tremendously by these reports, the travelers' records, and by the opinions that different colors are not equal to the whiteness of Europeans. Historic reports portray various skin colors not only as different, but also as a negative.
We can teach our children to appreciate their bodies and everyone as biological beings, equal in every respect.
Skin pigmentation is a subject of great sensitivity, and people have faced discrimination on the basis of skin pigmentation. For these reasons, scientists have shied away from this area of research. But it is important for me and many others to revisit this topic, and revisit it with new data and with also a new attitude toward public education.
We came to the rather unfortunate place we are in society as a result of human behavior. We know how these human behaviors were formed, and we know the cognitive impressions that go into fueling individual behavior. We cannot roll back the clock, but knowing what we know about behavior, we can make changes. We can make individual changes in our homes and classrooms, and it's these changes that can change society and the world in which we live. This takes will, this takes courage, it takes education, but it is do-able.
Pigmentation affects our health and our social well-being. We can attend to the issues related to health easily by being aware of our pigmentation and our lifestyle. How it affects our social well-being is much more complicated. The evolution of pigmentation and how pigmentation has been used in the past to provide a grounds for social discrimination, is something that every child must know. Then we, as a society, can learn a different lesson from the ones taught by the historical records. We can teach our children to appreciate their bodies and everyone as biological beings, equal in every respect.
Additional Information
Nina Jablonski’s Penn State faculty page
The Center for Human Evolution and Diversity (CHED)
Finding Your Roots Summer Camp
About the Author
Nina Jablonski, Ph.D.
The Pennsylvania State University
Nina G. Jablonski is Evan Pugh University Professor of Anthropology at The Pennsylvania State University. As a biological anthropologist and paleobiologist, she studies the evolution of adaptations to the environment in Old World primates including humans.
Her research program is focused in two major areas. Her paleoanthropological research concerns the evolutionary history of Old World monkeys, and currently includes an active field project in China. Her research on the evolution of human adaptations to the environment centers on the evolution of human skin and skin pigmentation, and includes an active field project examining the relationship between skin pigmentation and vitamin D production.
Jablonski is currently collaborating on the development of new approaches to science education in the United States. These approaches have the dual aims of improving the understanding of evolution and human diversity, and stimulating interest among students in pursuing science, technology, engineering, and mathematics courses and careers. With the support of NESCent (the National Evolutionary Synthesis Center) and active collaboration with Henry Louis Gates, Jr., she is leading a group of 30 scholars in the development of “genetics and genealogy” curricula for K-12 and undergraduate university students.
Jablonski also leads a major new scholarly initiative aimed at studying the effects of race in South African society. With the support of the STIAS (the Stellenbosch Institute for Advanced Study), she is the convener of the “Effects of Race” (EOR) program, which will bring together a select group of senior and junior scholars yearly to formulate new approaches to the study of race and the mitigation of racial discrimination.
Photo Credit: Fotolia/olly
