Research

(please email Tess Wilson at tmw119@psu.edu for reprint requests)

Evolution of Human Skin Pigmentation

Research on the evolution of skin color in humans was avoided by scientists for many years. Skin color is worthy of scientific investigation, however, because it is the product of over five million years of evolution in the human lineage, it the most obvious characteristic in which people vary in their appearance, and it is of great social importance. My research on the evolution of human skin and skin color, done mostly in collaboration with George Chaplin, has demonstrated that skin color is the product of natural selection acting to regulate levels of melanin pigment in the skin relative to levels of ultraviolet radiation (UVR) in the environment. Melanin is a natural sunscreen that prevents the breakdown of certain essential biomolecules (in particular, the B vitamin folate, and DNA), while permitting enough UVR to enter the skin to promote the production of essential vitamin D.

Selected publications:

Jablonski, N. G., & Chaplin, G. (2017). The colours of humanity: The evolution of pigmentation in the human lineage. Philosophical Transactions of the Royal Society B: Biological Sciences, 372(1724).
doi:10.1098/rstb.2016.0349
Jablonski.2017.PTRSB

Coussens, A. K., Naude, C. E., Goliath, R., Chaplin, G., Wilkinson, R. J., & Jablonski, N. G. (2015). High-dose vitamin D3 reduces deficiency caused by low UVB exposure and limits HIV-1 replication in urban Southern Africans. Proceedings of the National Academy of Sciences, 112(26), 8052-8057.
doi: 10.1073/pnas.1500909112
Coussens.2015.PNAS

Jablonski, N. G. (2014). Is there a golden mean for sun exposure? Journal of Internal Medicine, 276 (1), 71-73.
doi: 10.1111/joim.12248
Jablonski.2014.J.Int.Med

Jablonski, N. G., and Chaplin, G. (2013). Epidermal pigmentation in the human lineage is an adaptation to ultraviolet radiation. Journal of Human Evolution, 65(5), 671-675.
doi: 10.1016/j.jhevol.2013.06.004
Jablonski.2013.JHE.671ff

Swiatoniowski, A. K., Quillen, E., Shriver, M. D., and Jablonski, N. G. (2013). Comparing von Luschan skin color tiles and modern spectrophotometry for measuring human skin pigmentation. American Journal of Physical Anthropology, 151(2), 325-330.
doi: 10.1002/ajpa.22274
Swiatoniowski.2013.AJPA.325ff

Jablonski, N. G., and Chaplin, G. (2012). Human skin pigmentation, migration and disease susceptibility. Philosophical Transactions of the Royal Society B: Biological Sciences, 367(1590), 785-792.
doi: 10.1098/rstb.2011.0308
Jablonski.2012.PTRSC.B.785ff

Jablonski, N. G. (2012). The evolution of human skin colouration and its relevance to health in the modern world. Journal of the Royal College of Physicians of Edinburgh, 42(1), 58-63.
doi:10.4997/JRCPE.2012.114
Jablonski.2012.JRCPE.58ff

Jablonski, N. G., & Chaplin, G. (2010). Human skin pigmentation as an adaptation to UV radiation. Proceedings of the National Academy of Sciences, 107(S2), 8962-8968.
doi: 10.1073/pnas.0914628107
Jablonski.2010.PNAS.8962ff

Jablonski, N. G. (2010). Skin coloration. In M. I. Muehlenbein (Ed.), Human Evolutionary Biology (pp. 192-213). Cambridge: Cambridge University Press.

Chaplin, G., & Jablonski, N. G. (2009). Vitamin D and the evolution of human depigmentation. American Journal of Physical Anthropology, 139(4), 451-461.
doi: 10.1002/ajpa.21079
Chaplin.2009.AJPA.451ff

Jablonski, N. G. (2004). The evolution of human skin and skin color. Annual Review of Anthropology, 33, 585-623.
doi: 10.1146/annurev.anthro.33.070203.143955
Jablonski.2004.ARA.585ff

Jablonski, N. G., & Chaplin, G. (2000). The evolution of human skin coloration. Journal of Human Evolution, 39(1), 57-106.
doi: 10.1006/jhev.2000.0403
Jablonski.2000.JHE.57ff

Evolution of Old World Monkeys

The Old World monkeys (Superfamily Cercopithecoidea) comprise one of the most geographically widespread and diverse lineages of primates that has ever existed. Although their evolutionary history dates back to the early Miocene, evidence of Old World monkeys becomes common in the fossil record only in the latest Miocene and Pliocene. The fossil record of the group in Africa is particularly rich and well-dated. My research has concentrated on illumination of the evolutionary history of the Theropithecus lineage. My research on the evolution of the snub-nosed monkeys of East Asia has led me to have a strong interest in the evolution of the colobine monkeys, especially in the significance of ruminant digestion in that group.

Selected publications:

Cerling, T. E., Chritz, K. L., Jablonski, N. G., Leakey, M. G., and Manthi, F. K. (2013). Diet of Theropithecus from 4 to 1 Ma in Kenya. Proceedings of the National Academy of Sciences, 110(26), 10507-10512.
doi: 10.1073/pnas.1222571110
Cerling.2013.PNAS.10507ff

Ji, X., Jablonski, N. G., et al. (2013). Juvenile hominoid cranium from the terminal Miocene of Yunnan, China. Chinese Science Bulletin, 58(31), 3771-3779.
doi: 10.1007/s11434-013-6021-x

Liedigk, R., Yang, M., Jablonski, N. G., et.al. (2012). Evolutionary history of the odd-nosed monkeys and the phylogenetic position of the newly described Myanmar snub-nosed monkey Rhinopithecus strykeri. PloS one, 7(5), e37418.
doi: 10.1371/journal.pone.0037418

Jablonski, N. G., & Frost, S. (2010). Cercopithecoidea. In L. Werdelin & W. J. Sanders (Eds.), Cenozoic Mammals of Africa (pp. 393-428). Berkeley, CA: University of California.

Jablonski, N. G., & Chaplin, G. (2009). The fossil record of gibbons. In S. Lappan & D. J. Whittaker (Eds.), The Gibbons: New Perspectives on Small Ape Socioecology and Population Biology (pp. 111-130). New York: Springer.

McBrearty, S., & Jablonski, N. G. (2005). First fossil chimpanzee. Nature, 437(7055),105-108.
doi:10.1038/nature04008
McBrearty.2005.Nature.105ff

Jablonski, N. G. (2003). The evolution of the tarsiid niche. In P. C. Wright, E. L. Simons & S. Gursky (Eds.), Tarsiers:  Past, Present, and Future (pp. 35-49). New Brunswick: Rutgers University Press.

Jablonski, N. G., Leakey, M. G., Kiarie, C., & Anton, M. (2002). A new skeleton of Theropithecus brumpti (Primates: Cercopithecidae) from Lomekwi, West Turkana, Kenya. Journal of Human Evolution, 43(6), 887-923.
doi: 10.1006/jhev.2002.0607
Jablonski.2002.JHE.887ff

Jablonski, N. G. (2002). Fossil Old World monkeys: The late Neogene radiation. In W. C. Hartwig (Ed.), The Primate Fossil Record (pp. 255-299). Cambridge, UK: Cambridge University Press.

Jablonski, N. G., Whitfort, M. J., Roberts-Smith, N., & Xu, Q. (2000). The influence of life history and diet on the distribution of catarrhine primates during the Pleistocene in eastern Asia. Journal of Human Evolution, 39(2), 131-157.
doi:10.1006/jhev.2000.0405
Jablonski.2000.JHE.131ff

Jablonski, N. G. (1995). The phyletic position and systematics of the douc langurs of Southeast Asia. American Journal of Primatology, 35(3), 185-205.
doi: 10.1002/ajp.1350350303
Jablonski.1995.AJP.185ff

Evolution of Primate Thermoregulation

The evolution of habitual bipedal posture and locomotion is considered the key innovation which distinguishes the human lineage. Despite its importance, our knowledge of the processes leading to the emergence of habitual bipedalism remains unclear, largely because the behaviors that provided the impetus for this momentous change were not preserved in the fossil record. My research on the evolution of human bipedalism and its ramifications has been done mostly in collaboration with George Chaplin. The premise of our research has been that the behaviors leading to the regular adoption of bipedal postures in hominins must have conferred considerable reproductive success to individuals engaging in those behaviors. Behaviors that were common (e.g., feeding, resting, sleeping) are not necessarily important in terms of their impact on reproductive success. For this reason, our research has emphasized the importance of bipedal displays and appeasement postures in the evolution of habitual bipedalism in human ancestors. These behaviors are important, especially in our closest African ape relatives, in determining the outcomes of agonistic encounters and of disputes over mating access in females.

Selected publications:

Chaplin, G., Jablonski, N. G., Sussman, R. W., and Kelley, E. A. (2014). The role of piloerection in primate thermoregulation. Folia Primatologica, 85(1), 1-17.
doi: 10.1159/000355007
Chaplin.2014.Folia.Prim.1ff

Jablonski, N. G., & Chaplin, G. (2004). Becoming bipedal: How do theories of bipedalization stand up to anatomical scrutiny? In F. C. Anapol, R. Z. German & N. G. Jablonski (Eds.), Shaping Primate Evolution: Form, Function and Behavior (pp. 281-296). Cambridge, UK: Cambridge University Press.

Chaplin, G., Jablonski, N. G., & Cable, N. T. (1994). Physiology, thermoregulation and bipedalism. Journal of Human Evolution, 27(6), 497-510.
doi:10.1006/jhev.1994.1066
Chaplin.1994.JHE.497ff

Jablonski, N. G., & Chaplin, G. (1993). Origin of habitual terrestrial bipedalism in the ancestor of the Hominidae. Journal of Human Evolution, 24(4), 259-280.
doi: 10.1006/jhev.1993.1021
Jablonski.1993.JHE.259ff

Jablonski, N. G., & Chaplin, G. (1992). The origin of hominid bipedalism re-examined. Archaeology in Oceania, 27(3), 153-160.
Jablonski.1992.AO.153ff

Development of a Genetics and Genealogy Curriculum

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