External auditory exostosis at the end of the world. The southernmost evidence according to the latitudinal hypothesis

PAOLA PONCE,; GABRIELA GHIDINI,; GONZÁLEZ-JOSÉ, ROLANDO

Birmingham

Congreso; 8th Congress of the British Association for Biological Anthropology and Osteoarchaeology; 2006

External auditory exostoses (EAE) are bony anomalies of the external auricular canal associated with prolonged exposure to cold water. According to the latitudinal hypothesis proposed by Kennedy (1986) the prevalence of this anomaly falls as the latitude increases north and south above the 45º because of the risk of suffering from hypothermia while swimming in very cold waters. As according to this author no previous anthropological evidence of EAE was found for populations living beyond this latitude in the southern hemisphere, the aim of this paper was to examine the evidence for EAE in the southernmost ethnographic group who ever inhabited the world. For this purpose, 101crania of adult males and females housed at different museums were used. They belonged to Amerindians who lived in the province of Tierra del Fuego from Argentina and Chile and practised a mixed economy of hunter gathering with marine resources. It was found that 3 out of 48 crania (6.25%) whose subsistence economy was mainly based on marine products exhibit EAE. On the other hand, among those whose diet was primarily based on hunting, the prevalence was 1.88% (1 out of 53 crania had EAE). This corresponds to a 3.9% of the total sample when both groups are pooled. Although the prevalence differences between both groups were not statistically significant (p<0.005), these results support the hypothesis that EAE is associated with exposure to cold water due to exploitation of marine resources. In accordance with Kennedy’ hypothesis the frequency of EAE was low, however, this is expected in such a hostile and harsh cold environment.   Research funded by the Durham Doctoral Fellowship Award (DDFA) and the Comisión Nacional de Investigaciones Científicas y Técnicas (CONICET)