An examination of proposed causes of auditory exostoses

Abstract

Auditory exostoses are a discrete trait, the presence of which may be a product of environmental factors. Water exposure is believed to be associated with the trait's appearance, which has allowed anthropologists to hypothesise about past population subsistence strategies. However, some scholars still contend that water exposure is not necessarily the precipitating factor for its development. This study examined 744 Nubians for exostoses from the following time periods: Kerma, Meroitic, X-group, Christian and a current sample. A total of six male individuals exhibited the characteristic. There is little evidence in the Nubian archaeological record to suggest that marine resources were exploited in a manner that required prolonged water exposure. Moreover, the Nubian groups with auditory exostoses were primarily agriculturists and/or pastoralists. Wind chill and temperature have also been put forth as potential contributors to the development of auditory exostoses, but like other hypotheses, water is also needed in order for wind chill and temperature to incite exostoses. Even though water may have contributed to the development of exostoses for many populations, it is not suitable to cite it as a precipitating factor for the development of auditory exostoses in Nubians. Based on this evidence, other non-water factors may be important in the trait's development. Caution must be used when interpreting exostoses as indicators of a particular water-related activity and trait frequencies must be carefully considered, as low frequencies are not necessarily evidence of water-exposure. Copyright © 2009 John Wiley & Sons, Ltd.