Ancestry of victims of 1755 Lisbon earthquake based on tooth morphology.

Abstract

The present investigation comprises the characterization of skeletal remains recovered from the 2004 archaeological excavations carried out in the Cloister's Southwest Wing of the Academy of Sciences of Lisbon, attributed to the 1755 earthquake. Among the remains, many teeth were found. Our goal is to use dental morphological characteristics to assess the geographic ancestry of the combined sample using the methods of biodistance and web-based application of the Arizona State University Dental Anthropology System 2. The crown and root traits of the ASUDAS were scored in a sample of 1068 disarticulated teeth, 65 skulls, 138 adult and 42 sub-adult jaws. Eight characteristics of 34 specimens (7 skulls and 27 jaws) were analyzed using rASUDAS2. Results demonstrate that 73.5% of this sample can be assigned to Western Eurasian ancestry, with the remaining 26.5% divided between Sub-Saharan Africa, non-Arctic and Arctic America, and East Asia. Euclidean and Bray-Curtis distance measures were used to put this Portuguese sample in a world context. From both distance matrixes, cluster analyses were used to generate dendrograms. Based on Bray-Curtis values, Portugal is closest to Western Europe, followed by India and Eastern Europe. For the tree based on Euclidean distances, India is the first to join Portugal, followed by Eastern and Western Europe. Therefore, on both an individual and group level, the Portuguese sample is most closely tied to Western Eurasia. However, there may be other ancestries in the sample, such as Sub-Saharan Africa, due to non-European migrants in Portugal along with the African slave trade to Brazil that reached its peak in 18th century Lisbon.