Nina Jablonski is a scientist, educator, author, and a strong advocate for racial equity. She is the Evan Pugh Professor of Anthropology at Pennsylvania State University and is dedicated to uncovering the evolution of human skin and skin pigmentation.
“The science of skin has been a very rewarding topic and one in which there is inexhaustible interest,” Jablonski said on ‘Reason with Science’, where she takes us on a journey of human evolution, the loss of our body hair and the gain of skin pigmentation, and how science can be used to dismantle racism.
A primatologist by training, Jablonski studied Old World monkeys during her doctoral research and described her transition to the ‘science of skin’ as an accident. In the early 1990s, a colleague had asked her to substitute for a class in introductory human biology on the subject of skin and that’s how it all started.
“I tried very hard to find information on the evolution of skin and skin color as I thought it might be of interest to the students, but I was shocked that there was so little information available,” Jablonski said. “I was mystified and wanted to investigate further because I knew this was a topic of great importance to people.”
The development of skin pigmentation is an important part of human evolution. The human lineage diverged from our ancestors– the African apes— around 8 million years ago. Although humans have migrated around the world, our ape ancestors have remained in Africa’s equatorial forests. As early humans often foraged, hunted, and escaped predators in open and non-forested areas, it became important to keep the body cool in high temperatures. Consequently, we gained eccrine sweat glands and lost most of our body hair. The evaporation of sweat from our naked skin helped to keep us cool, Jablonski explained.
“We never think about hair as being a good natural sunscreen, but it actually is a marvelous one,” she said. “When we lost most of the hairy sunscreen on our bodies, we substituted that with permanent and high concentrations of skin pigmentation in form of melanin.”
Melanin is an excellent natural sunscreen that protects us from the harmful effects of ultraviolet (UV) radiation. Interestingly, UV is not always bad for us. In fact, the synthesis of vitamin D, a molecule required for healthy bones, muscles, the immune system, and other bodily functions, requires sun exposure. Hence, darkly pigmented skin in equatorial regions is a response to high sun exposure as is depigmented skin in circumpolar regions with less sun–both are a product of evolution by natural selection.
“Until a few thousand years ago, our skin pigmentation was fine-tuned to our lifestyles and our geographic position in the world,” Jablonski said. “It reflected the ultraviolet regimes that our ancestors were exposed to.”
But unlike our ancestors, modern humans are out of touch with the environment. Due to indoor and sedentary lifestyles, we cannot make adequate amounts of vitamin D in our bodies. It is therefore important to make mindful choices about our activity levels, habits, and diets to compensate for the lost levels of vitamin D.
According to Jablonski skin pigmentation is an endlessly fascinating subject, important not only from an evolutionary standpoint but also for its implications on human health.
In addition to her scientific work, Jablonski has given a TED talk and authored popular books to inform people about the science of skin. She believes that educating young people about the history of skin color and the interesting genetic stories behind it can go a long way in dismantling the prejudices of race. Her children’s book ‘Skin We Are In’, coauthored with South African writer Sindiwe Magona, has garnered much acclaim.
“For parents, teachers, and social workers it is important to recognize that you can tell kids about the evolution of skin, and they get it,” she said. “We have to get these [scientific stories] out into the grassroots education so that the young generation can appreciate the beautiful diversity of humans around the world.”
Jablonski was also a co-convener of the Effects of Race project at the Stellenbosch Institute for Advanced Study and her contributions to the worldwide fight against racism was recognized by the University of Stellenbosch with an honorary doctorate. Additionally, she has encouraged tearing down of the historical fallacies of racial constructs in an interview with the Big Ten Network.
“Races have never existed in nature, they were formulated by people who had opinions and very few facts,” she said. “A lot of my research is to educate people that we are not human races, we are one people of different colors.”
The complete video of this interview with is available on the YouTube channel of our media partner, ‘Reason with Science’. It is a series of conversations with scientists discussing the importance of science in society. You can listen to the full conversation with Dr. Jablonski here:
https://www.youtube.com/watch?v=deQM7QsPuVc
Author
Sneha Das is pursuing her Ph.D. in Microbiology from the University of Illinois at Urbana-Champaign. She fell in love with the microbial world during her undergraduate education at St. Xavier’s College, Kolkata. Her current research focuses on understanding DNA damage and repair in bacteria using genetic tools. Sneha discovered her passion for science communication as a teaching assistant for undergraduate Molecular Biology and Microbiology courses. Since then, she has talked about different scientific topics to the general audience as a part of science communication outreach programs. In her free time, she enjoys writing, traveling, exploring nature, and meeting new people.
Editors
Ananya Sen is currently a science writer at the Carl R. Woese Institute for Genomic Biology. She completed her Ph.D. in Microbiology at the University of Illinois at Urbana-Champaign in 2021. She is an ardent reader and will happily discuss anything from Jane Austen to Gillian Flynn. Her travel goals include covering all the national parks in the U.S. with her sidekick Oscar, a Schnauzer/Pomeranian mix.
Sumbul Jawed Khan is the Assistant Editor-in-Chief at Club SciWri. She received her Ph. D. from the Indian Institute of Technology Kanpur, where she studied the role of the microenvironment in cancer progression and tumor formation. During her post-doctoral research at the University of Illinois at Urbana-Champaign, she investigated the gene regulatory networks important for tissue regeneration. She is committed to science outreach activities and believes it is essential to inspire young people to apply scientific methods to tackle the challenges faced by humanity. As an editor, she aims to simplify, translate, and excite people about current advances in science.
Roopsha Sengupta is the Editor-in-Chief at Club SciWri. She did her Ph.D. at the Institute of Molecular Pathology, Vienna, and post-doctoral research at the University of Cambridge UK, specializing in Epigenetics. During her research, she was involved in many exciting discoveries and had the privilege of working and collaborating with many inspiring scientists. As an editor for Club SciWri, she loves working on diverse topics and presenting articles coherently while nudging authors to give their best.
Illustrator
Andreia Rocha did her M.Sc. at Universidade do Algarve in Faro, Portugal, in Oncobiology and moved to Vienna to complete her thesis at IMBA where she studied stem cells and focused on working with organoids while using them as cancer models. Currently, she is a research assistant at JLP Health, a startup company based in Vienna, Austria. She is also passionate about communicating science through art and illustration and wishes to combine the two careers in the future. You can visit her website and follow her on instagram.
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