By Cláudia Relvado
Sex diagnosis is fundamental to determine the biological profile of individuals and for the study of past human populations. It is crucial for understanding social-cultural aspects of past populations, such as possible sex differences related to occupational activity, diet and mobility (e.g. Lozano et al., 2020; Robb and Harris, 2018). However, it can be difficult to estimate in non-adults, in very fragmented remains, and in archaeological contexts which result from complex funerary behaviours that involved manipulation of the human remains and subsequent commingling (Cox and Mays, 2000). That is the case in Perdigões, which displays collective funerary contexts with ossuaries, almost no primary depositions, cremations and bones dispersed in ditches (Godinho et al., 2019; Valera et al., 2014; Valera & Godinho, 2010).
The sex estimation of human skeletal remains is usually estimated using morphological (e.g., os coxae and skull) and metric methods, and its reliability is strictly related to the morphological preservation of the bones. It can also be determined via ancient DNA, however, this method, besides being expensive, is dependent on collagen preservation.
Recently, Stewart and colleagues (2017) developed a method for sex diagnosis that only requires a small portion of dental enamel (it uses peptides from this dental tissue). Tooth enamel is made up essentially of a protein called amelogenin that is sexually dimorphic, which means it has small differences in its amino acid sequence depending on X or Y chromosomes. It is expected that females will have only the AMELX sequence and males the AMELX and AMELY sequences (such differences reflect the chromosome composition of males and females). As dental enamel is highly resistant to taphonomic factors, this technique is much more reliable than the previous ones and has the advantage of being quick, minimally destructive, and cheaper than old DNA analyses.
This methodology will be applied for the first time on teeth from Portuguese prehistoric contexts, among them teeth from tombs 3 and 4 of Perdigões. During the next few months, an internship will be carried out at the University of Copenhagen focused on learning and applying this promising and innovative methodology, which will later be introduced in Portugal. In this context, its application will be an added value and a very important tool for understanding the life of these communities.
Cox, M., & Mays, S. (2000). Human Osteology: In Archaeology and Forensic Science. Cambridge University Press.
Godinho, R. M., Gonçalves, D., & Valera, A. C. (2019). The preburning condition of Chalcolithic cremated human remains from the Perdigões enclosures (Portugal). International Journal of Osteoarchaeology, 29(5), 706–717.
Lozano, M., Jiménez-Brobeil, S. A., Willman, J. C., Sánchez-Barba, L. P., Molina, F., & Rubio, Á. (2021). Argaric craftswomen: Sex-based division of labor in the Bronze Age southeastern Iberia. Journal of Archaeological Science, 127, 105239.
Robb, J., & Harris, O. J. T. (2018). Becoming Gendered in European Prehistory: Was Neolithic Gender Fundamentally Different? American Antiquity, 83(1), 128–147.
Stewart, N. A., Gerlach, R. F., Gowland, R. L., Gron, K. J., & Montgomery, J. (2017). Sex determination of human remains from peptides in tooth enamel. Proceedings of the National Academy of Sciences, 114(52), 13649–13654.
Valera, A. C., & Godinho, R. M. (2010). Ossos Humanos Provenientes dos Fossos 3 e 4 e Gestão da Morte nos Perdigões. Apontamentos de Arqueologia e Património, 6, 29–39.
Valera, A., Silva, A., Cunha, C., & Shaw Evangelista, L. (2014). Funerary practices and body manipulation at Neolithic and Chalcolithic Perdigões ditched enclosures (South Portugal). Em A. C. Valera (Ed.), Recent Prehistoric Enclosures and Funerary Practices in Europe (Vol. 2676). BAR International Series 2676.
Relvado, C. (2021), Sex diagnosis through dental enamel peptides applied in Tombs 3 and 4 from Perdigões, Short Notes, www.perdigões.org