Osteological, multi-isotope and proteomic analysis of poorly-preserved human remains from a Dutch East India Company burial ground in South Africa

Abstract

Skeletal remains discovered in Simon's Town, South Africa, were hypothesised as being associated with a former Dutch East India Company (VOC) hospital. We report a novel combined osteological and biochemical approach to these poorly-preserved remains. A combined strontium (⁸⁷Sr/⁸⁶Sr), oxygen (δ¹⁸O_VPDB) and carbon (δ¹³C_VPDB) isotope analysis informed possible childhood origins and diet, while sex-specific amelogenin enamel peptides revealed biological sex. Osteological analyses presented evidence of residual rickets, a healed trauma, dental pathological conditions, and pipe notches. The combined isotope analyses yielded results for 43 individuals which suggested a diverse range of geological origins, including at least 16% of the population being non-local. The inclusion of δ¹³C_VPDB had intriguing implications for three individuals who likely did not have origins in the Cape Town region nor in Europe. Peptide analysis on the dental enamel of 25 tested individuals confirmed they were all biologically male. We suggest that isolated enamel may provide crucial information about individuals' pathological conditions, geographical origins, diet, and biological sex. These data further demonstrated that a combined approach using multiple osteological and biochemical methods is advantageous for human remains which are poorly preserved and can contextualise a site with little direct evidence.

Figure 1

Map of South Africa, and map of Cape peninsula region with Simon’s Town highlighted. Maps compiled and created by authors.

Figure 2

Reconstructed ion chromatograms demonstrating detection of both AMELX and AMELY peptides from enamel extract of tooth from burial 9. Data are representative of results for all 25 samples analysed.

Figure 3

Boxplots of isotope data for 43 analysed individuals from Simon’s Town, South Africa burial site. Key: Whiskers represent minimum and maximum values of data according to the interquartile range rule. The top box represents the 3rd quartile, and the lower box represents the 1st quartile. The top box line represents the median of the 3rd quartile, the middle line represents the median of the whole dataset, and the lower box line represents the median of the 1st quartile. The × visible within the box represents the mean. All data points that are present outside of the whisker range represent suspected outliers.

Figure 4

Expected local (a) strontium ratios*¹ and (b) oxygen values*² from water sources in the Cape region of South Africa, as referenced in this research to develop expected local ranges. *¹Image (a) Schematic geological map representing archaeological fauna and human Sr values from Sealy et al., Balasse et al., and Radloff et al.. Image modified from Kootker et al.; Fig. 2. Schematic geological map of the southwestern Cape. *²Image (b) Modified image from West et al. isoscape, developed with geospatial and oxygen data.

Figure 5

Box plots comparing isotope data between 36 individuals from the Cobern Street, South Africa burial site, and 43 individuals from the Simon’s Town, South Africa burial site. Key: Whiskers represent minimum and maximum values of data according to the interquartile range rule. The top box represents the 3rd quartile, and the lower box represents the 1st quartile. The top box line represents the median of the 3rd quartile, the middle line represents the median of the whole dataset, and the lower box line represents the median of the 1st quartile. The × visible within the box represents the mean. All data points that are present outside of the whisker range represent suspected outliers.