Nina Jablonski


Nina G. Jablonski is an American anthropologist and palaeobiologist, known for her research into the evolution of skin color in humans. She is engaged in public education about human evolution, human diversity, and racism. She is an Evan Pugh University Professor at The Pennsylvania State University, and the author of the books Skin: A Natural History, and Living Color: The Biological and Social Meaning of Skin Color.

Early life and education

Jablonski grew up on a farm in upstate New York State. With encouragement from her parents, Jablonski began her exploration into the world of science when she was quite young.  She recalls exploring the nature around her home, digging for fossils near creeks and trees. Jablonski's interest in studying human evolution stemmed from watching a National Geographic feature on Louis Leakey, a famous paleontologist, that aired in the mid- 1960s. Louis Leakey's study at Olduvai Gorge in East Africa and his focus on the hominid Zinjanthropus boisei sparked Jablonski's attention. She instantly decided that she wanted to pursue the study of human evolution, dismissing her parents' desire for her to attend medical school.
Jablonski earned an A.B. degree in biology from Bryn Mawr College in 1975. In 1978, after three years working as a Teaching Assistant in the Department of Anthropology at the University of Washington, she entered the PhD program at the University of Washington, receiving a PhD in anthropology in 1981 for her dissertation: Functional Analysis of the Masticatory Apparatus of Theropithecus gelada She was awarded a DPhil. from Stellenbosch University in 2010. She has held teaching positions at the University of Hong Kong and The University of Western Australia. During these years, Nina began her research on the evolution of human bipedalism and skin color.
Jablonski is married to George Chaplin, who is another professor as well as her research collaborator at Penn State University.  She can also write and speak fluently in Putonghua, and is also able to write in both Latin and German.

Career

During her time at the University of Washington, Jablonski conducted research at the University of Hong Kong, in both the Department of Anatomy and the Prince Philip Dental Hospital. After completing her PhD, Jablonski was a lecturer in the Department of Anatomy at the University of Hong Kong from 1981 to 1990, where she was able to continue her research into comparative anatomy and paleontology. She began research in cooperation with the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing in 1982 and the Kunming Institute of Zoology in 1984. Additionally, Jablonski was inspired to begin her research on the natural history of human skin during her time in Hong Kong.
After her time in Hong Kong, Jablonski moved to Australia with her husband, George Chaplin, where she worked in the Department of Anatomy and Human Biology at the University of Western Australia from 1990-1994 as a senior lecturer. During this period of time, she began research on the evolution of human bipedalism and the evolution of human skin color, which is the foundation of her further research in anthropology. She thought the study on such topics was valuable for researchers to use the basic tools of comparative and historical biology to deduce what probably happened in the past.
From 1994 to 2006, she held the Irvine Chair of Anthropology at the California Academy of Sciences in San Francisco. During this time, she was also a member of the American Association for the Advancement of Science. Additionally, she was also an editor for The First Americans: The Pleistocene Colonization of the New World, a book about the ideas and opinions from analyzing the sources from Siberia to Chile, to tell the history of how the mankind found and got into the Americas.
After leaving the California Academy of Sciences, she moved to Penn State University, where she served as head of the Anthropology Department from 2006 to 2011. She is currently an Evan Pugh Professor of Anthropology at Penn State University. Jablonski's main research topics at Penn State focus on the evolution of Old World monkeys, primate thermoregulation, and human skin pigmentation. Starting in 2012 in partnership with Henry Louis Gates, Jr., host of the PBS show Finding Your Roots, she started a curriculum to get younger students of color more interested in STEM.

Research

Jablonski researches human and primate evolution. She is known for her research into human skin, and has published two books on the subject. She researches the origin and evolution of the skin and skin pigmentation and the relationships between vitamin D requirements and metabolism in the context of human migration and urbanization. In 2012 she was awarded a Guggenheim Fellowship to carry out research into human vitamin D production in natural conditions with the goal of informing public health interventions addressing vitamin D deficiency.

Skin color

Jablonski studies the physiological functions of skin as well as the evolutionary and sociological influences of the past and today. Early in her skin research, she published papers on the connection between neural tube defects and ultraviolet radiation which damages folate in the skin, in the controversial and non-peer reviewed journal ''Medical Hypotheses'. She also collaborated with George Chaplin to study the pattern of melanin distribution among populations at different latitudes, discovering a correlation between skin color and the amount of ultraviolet radiation present in the individual's geographic location. Jablonski and Chaplin later theorized that dark skin with sweat glands evolved with the loss of hair and sexual dimorphism in skin color.  Jablonski's major findings explain that the physiological purpose for the variation in skin color around the world is due to the balance between the need to protect against UV radiation and facilitating the production of vitamin-D. Heightened melanin levels occur in populations closer to the equator where UV radiation poses risks of folate damage and depigmentation occurs in areas with low levels of UV radiation so that vitamin-D biosynthesis is not inhibited.
Jablonski has taken this connection and applied it to the modernizing lifestyle. Jablonski connects certain diseases and health risks to people living in areas where their skin color is maladaptive to the environment and people who are living the modern indoors lifestyle. The main diseases she found to be connected with low levels of UV-B exposure are rickets and multiple sclerosis due to inadequate production of vitamin D. The main health problems related to too much UV radiation are cutaneous malignant melanoma, a type of skin cancer, as well as birth defects that are due to folate depletion.

Old World monkeys

Jablonski's research on Old World monkeys is marked by extensive paleontological field work across Africa and Asia. Her work has led to significant discoveries including an ape cranium in China, and the first identified chimpanzee fossils. In 2004, along with Sally McBrearty, Jablonski discovered teeth dating back to ~545,000 years ago in the Kapthurin Formation belonging to the genus Pan by comparing their measurements to those of modern Pan teeth. Paleoecological evidence at the site showed that chimpanzees were not restricted to forest habitats. Along with the discovery of nearby Homo fossils of the same age, this provided the first fossil evidence for spatiotemporal coexistence between the two genera. More recently, Jablonski's fossil discoveries have been complemented by phylogenetic analysis of modern apes, suggesting that genomic divergence in ancestral gibbons was in part due to habitat shifts during the Miocene–Pliocene transition.
Jablonski's research on the genus Theropithecus also had significant impact, including the discovery of a near-complete skeleton of T. brumpti. This finding established T. brumpti as a terrestrial monkey similar to the modern T. gelada, albeit much larger. Her research is central to modern understanding of extinct Theropithecus size, habitat, and diet, much of which is detailed in Theropithecus: The Rise and Fall of a Primate Genus, edited by Jablonski. She has also written textbook analyses of the fossil record of tarsiers, gibbons, and Cercopithecoidea as a whole.

Primate thermoregulation

In 1994, Jablonski argued against a theory proposed by Peter Wheeler that thermoregulation played a role in hominids’ transition to bipedalism. Wheeler hypothesized that there was evolutionary pressure for early hominids to adopt bipedalism because an upright stance with less surface area exposed to sunlight allowed them to forage for longer without overheating. Jablonski's team constructed their own models, which led to the conclusion that thermoregulatory benefits weren't significant enough for natural selection to favor bipedalism.
In 2014, Jablonski began researching the adaptation of goose bumps because she was interested in the connection between the integument of ring-tailed lemurs and thermoregulation. The mechanism for goose bumps is the contraction of smooth muscle called Musculi Arrectores Pilorum. Jablonski noted that early primates did not have effective networks of MAP throughout the body, a factor that may have significantly affected their ability to forage under the cooler conditions of the late Eocene epoch. Using this information, she concluded that the absence of MAP networks in early primates likely contributed to their extinction in non-tropical latitudes. Jablonski also made connections between goose bumps and brain size, as the ability to regulate body temperature without changes in metabolism seemed to her a necessary adaptation to accommodate the thermal and metabolic sensitivities of larger brains.
Jablonski is also interested in exploring how the behaviors of ring-tailed lemurs relate to thermoregulation. In 2016, she traveled to Madagascar where she concluded that lemurs depend on behaviors of sunbathing and huddling to retain heat.

Publications