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Judith Sealy

Judith Sealy holds the South African Research Chair in Stable Isotopes, Archaeology and Palaeoenvironmental Studies, based in the Department of Archaeology at UCT. She also holds overall academic responsibility for the Stable Light Isotope laboratory, used by researchers from a range of disciplines at UCT and other universities nationally and internationally. Sealy and her research group measure naturally occurring variations in the ratios of stable light isotopes (mainly carbon, nitrogen and oxygen) to investigate past diets and environments. Isotopic studies of human remains enable inferences about the diet and economic base of human societies, from the emergence of modern humans to the development of hunter-gatherer, herder and farmer societies in southern Africa, and the impact of European colonization. The research group also studies ancient animal remains to reconstruct past environments, helping us to understand the context/constraints within which humans evolved and lived.  Sealy is a former editor of the South African Archaeological Bulletin, a former Associate Editor of the Journal of Archaeological Science and Archaeometry, and currently serves on the editorial boards of Azania and Southern African Humanities. She is a Fellow of the Royal Society of South Africa and of the University of Cape Town.

Recent publications

Dlamini, N., Sealy, J. & Mayor, A. 2019. Diet variability among pre-Dogon and early Dogon populations (Mali) from stable isotopes and dental diseases. American Journal of Physical Anthropology doi: 10.1002/ajpa.23831

Loftus, E., Lee-Thorp, J., Leng, M., Marean, C. & Sealy, J. 2019. Seasonal scheduling of shellfish collection in the Middle and Later Stone Ages of southern Africa. Journal of Human Evolution 128: 1-16.  doi: 10.1016/j.jhevol.2018.12.009

Luyt, J., Hare, V.J. & Sealy, J. 2019. The relationship of ungulate d13C and environment in the temperate biome of southern Africa, and its palaeoclimatic application. Palaeogeography, Palaeoclimatology, Palaeoecology 514: 282-291. doi: 10.1016/j.palaeo.2018.10.016

Carr, A.S., Bateman, M.D., Cawthra, H.C. & Sealy, J. 2019. First evidence for onshore marine isotope stage 3 aeolianite formation on the southern Cape coastline of South Africa. Marine Geology 407: 1-15.  doi: 10.1016/j.margeo.2018.10.003

Zhu, M. & Sealy, J. 2019. Multi-tissue stable carbon and nitrogen isotope models for dietary reconstruction: evaluation using a southern African farming population. American Journal of Physical Anthropology 168: 145–153.  doi: 10.1002/ajpa.23731

Lewis, M.C. & Sealy, J.C. 2018. Coastal complexity: ancient human diets inferred from Bayesian stable isotope mixing models and a primate analogue. PLoS One 13(12): e0209411.  doi: 10.1371/journal.pone.0209411

Dyvart, K.F., Sealy, J. & Fredriksen, P.D. 2018. Osteological and stable isotope (δ13C and δ15N) analysis of faunal remains from Khami, Zimbabwe. Azania: Archaeological Research in Africa 53(4): 507-527. doi: 10.1080/0067270X.2018.1540215

Rey K., Day, M.O., Amiot, R., Goedert, J., Lécuyer, C., Sealy, J. & Rubidge, B.S. 2018. Stable isotope record implicates aridification without warming during the late Capitanian mass extinction. Gondwana Research 59: 1-8. doi: 10.1016/

Luyt, J. & Sealy, J. 2018. Inter-tooth comparison of δ13C and δ18O in ungulate tooth enamel from south-western Africa. Quaternary International 495: 144-152. doi: 10.1016/j.quaint.2018.02.009

Hopper, C., Sealy, J.C. & Dewar, G. 2018. Little Ice Age drought event reconstructed from isotopic analysis of archaeological springbok (Antidorcas marsupialis) teeth. Palaeogeography, Palaeoclimatology, Palaeoecology 495: 105-112. doi: 10.1016/j.palaeo.2017.09.019

Lehmann, S.B., Levin, N.E, Braun, D.R., Stynder, D.D, Zhu, M., le Roux, P.J. & Sealy, J. 2018. Environmental and ecological implications of strontium isotope ratios in mid-Pleistocene fossil teeth from Elandsfontein, South Africa. Palaeogeography, Palaeoclimatology, Palaeoecology 490: 84-94.  doi: 10.1016/j.palaeo.2017.10.008

Loftus, E., Sealy, J., Leng, M.J. & Lee-Thorp, J.A. 2017. A Late Quaternary record of seasonal sea surface temperatures off southern Africa. Quaternary Science Reviews 171: 73-84.  doi: 10.1016/j.quascirev.2017.07.003

Collins, J.A., Carr, A.S., Schefuß, E., Boom, A. & Sealy, J. 2017. Investigation of organic matter and biomarkers from Diepkloof Rock Shelter, South Africa: insights into Middle Stone Age site usage and palaeoclimate. Journal of Archaeological Science 85: 51-65.

Pfeiffer, S., Sealy, J.C., Williamson, R.F., Forrest, C., Lesage, L. 2017. Patterns of weaning among ancestral Huron-Wendat communities, determined from nitrogen isotopes. American Antiquity 82(2): 244–261.

Galimberti, M., Loftus, E. & Sealy, J. 2017. Investigating δ18O of Turbo sarmaticus (L. 1758) as an indicator of sea surface temperatures. Palaeogeography, Palaeoclimatology, Palaeoecology 484: 62-69.

Dlamini, N., Morris, A.G. & Sealy, J. 2016. Carbon isotopes and dental caries as evidence for regional variation in the diets of early farming communities from Katanga, Democratic Republic of the Congo. Journal of African Archaeology 14(2): 135-153. 

Sealy, J., Lee-Thorp, J.A., Loftus, E., Faith, J.T. & Marean, C.W. 2016. Late Quaternary environmental change in the Southern Cape, South Africa from stable carbon and oxygen isotopes in faunal tooth enamel from Boomplaas Cave. Journal of Quaternary Science 31(8): 919-927.

Coutu, A.N., Whitelaw, G., le Roux, P., & Sealy, J. 2016. Earliest evidence for the ivory trade in southern Africa: isotopic and ZooMS analysis of 7th-10th century AD ivory from KwaZulu-Natal. African Archaeological Review 33:411–435.

Pfeiffer, S., Sealy, J.C., Williamson, R.F., Needs-Howarth, S. & Lesage, L. 2016. Maize, fish and deer: Investigating dietary staples among ancestral Huron-Wendat villages, as documented from tooth samples. American Antiquity 81(3): 515-532.

Loftus, E., Sealy, J. & Lee-Thorp, J. 2016. New radiocarbon dates and Bayesian models for Nelson Bay Cave and Byneskranskop 1: implications for the South African Later Stone Age sequence. Radiocarbon 58(2): 365- 381.

Sealy, J. 2016. Intensification, diet and group boundaries among Later Stone Age coastal hunter-gatherers along the western and southern coasts of South Africa. In: J. Lee-Thorp & M.A. Katzenberg (eds) The Oxford Handbook of the Archaeology of Diet. Oxford: Oxford University Press. doi:10.1093/oxfordhb/9780199694013.013.37

Sealy, J. 2016. Cultural change, demography, and the archaeology of the last 100 kyr in southern Africa. In: S.C. Jones & B.A. Stewart (eds) Africa from MIS 6-2: Population Dynamics and Palaeoenvironments: 65-75. Dordrecht: Springer. ISBN 978-94-017-7520-5

Stowe, M.J. & Sealy, J. 2016. Terminal Pleistocene and Holocene dynamics of southern Africa's winter rainfall zone based on carbon and oxygen isotope analysis of bovid tooth enamel from Elands Bay Cave. Quaternary International 404: 57-67.

Irish, J.D., Black, W., Sealy, J. & Ackermann, R.R. 2014. Questions of Khoesan continuity: Dental affinities among the indigenous Holocene peoples of South Africa. American Journal of Physical Anthropology 155: 33-44.

Makarewica, C.A. & Sealy, J. 2015. Dietary reconstruction, mobility, and the analysis of ancient skeletal tissues: Expanding the prospects of stable isotope research in archaeology. Journal of Archaeological Science 56: 146-158.

Sealy, J., Johnson, M., Richards, M. & Nehlich, O. 2014. Comparison of two methods of extracting bone collagen for stable carbon and nitrogen isotope analysis: comparing whole bone demineralization with gelatinization and ultrafiltration. Journal of Archaeological Science 47: 64-69.