Kinship and the familial occurrence of skeletal developmental anomalies in the noble Swéerts-Sporck family (Bohemia, 17th to 20th centuries)

Abstract

Objective: To determine the degree of similarity of biologically related individuals according to the occurrence of skeletal developmental anomalies (SDA), to see whether these anomalies reflect documented biological relationships.

Material and methods: The sample consists of the skeletal remains of seven members of the noble Swéerts-Sporck family from the 17th-20th centuries. Eighty-nine SDA were examined using morphological assessment, X-ray and CT. The degree of similarity was calculated using a similarity coefficient (Cvrček et al., 2018).

Results: There were three shared SDA in the sample (cranial shift at the C-T border, cervical ribs, hypoplasia of rib 12), and another fifteen individual SDA were reported. The degree of similarity between individuals supports their documented relationships. The greatest similarity was found in closely related individuals such as father/son or siblings, and the least between unrelated individuals.

Conclusions: SDA can be used as a supportive tool for detecting family relationships. The results correspond to the conclusions of earlier analyses of non-metric traits and frontal sinuses in the same sample: the smaller the biological distance between individuals, the greater the degree of their similarity.

Significance: Using unique human skeletal collections, this communication contributes to the expansion of knowledge about the familial occurrence of SDA.

Limitations: The small number of individuals limits the use of statistical approaches.

Suggestions for further research: The results call for research on this topic using a larger sample with known genealogical data and the same approaches, to confirm our conclusions.

Keywords: Aristocracy; Biological distance; Genealogically documented sample; Inbreeding; Similarity coefficient.