Cold-water diving in the tropics? External auditory exostoses among the pre-Columbian inhabitants of Panama.

Abstract

The appearance of external auditory exostoses archaeologically has been attributed to aquatic activities in middle latitudes. However, recent clinical research implicates low sea surface temperatures, especially below a threshold of 19°C, as a stronger predictor of ear exostosis development than latitude. Here, we examine the frequency of external auditory exostoses in human remains from nine pre-Columbian archaeological sites in Panama, representing individuals from a warm, tropical region. External auditory exostoses were recorded as present when an abnormal bony growth was observed macroscopically within the ear canal. The presence of exostoses was compared by right and left side, geographical region, sex, and degree of stenosis. A total of 125 adult individuals made up the observable sample analyzed in this study. Exostoses were observed in seven males and one female. All individuals affected by this pathology were excavated from mortuary contexts along the Gulf of Panama-a region characterized by intense cold water upwelling in the dry season. This study suggests that external auditory exostoses in pre-Columbian Panama affected individuals involved in habitual aquatic activities in the cold, upwelled waters of the Gulf of Panama. These activities appear to be almost exclusively dominated by male individuals. Ethnohistorical and archaeological records point to marine shell resource acquisition by deep-water diving as the activity driving exostosis development in pre-Columbian Panama.