SHORT REPORT An Examination of Proposed Causes of Auditory Exostoses K. GODDE* Department of Anthropology, California State University, Sacramento, Sacramento, CA 95819, USA ABSTRACT Auditory exostoses are a discrete trait, the presence of which may be a product of environ- mental 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 agri- culturists 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 ß 2009 John Wiley & Sons, Ltd. Key words: auditory exotoses; Nubians; discrete traits; subsistence strategies Introduction The appearance of non-metric traits has been linked to both genetic and environmental influences, with auditory exostoses identified as the most prominent environmentally induced trait. Auditory exostoses are boney growths of the external auditory meatus that can grow to completely occlude the ear canal. The most recent anthropological work suggests that audi- tory exostoses are caused by the interactions of water, temperature and wind chill in tropical or subtropical areas (Okumura et al., 2007). Prior studies cite water exposure (Ascenzi & Balistreri, 1975; Standen et al., 1997), or more specifically, cold-water exposure (Kennedy, 1986; Frayer, 1988; Manzi et al., 1991; Velasco-Vazquez et al., 2000) as the cause. Some scholars postulate that a combination of factors, including biological and chemical, affect the trait’s appearance (Hutch- inson et al., 1997). While genetic traits can yield insight into biological relationships, environmen- tal traits are beneficial because they can yield information about subsistence strategies (Ken- nedy, 1986; Frayer, 1988; Standen et al., 1997; Velasco-Vazquez et al., 2000), and/or social practices (Manzi et al., 1991). In order to investigate the water exposure and non-water factors hypotheses, this study International Journal of Osteoarchaeology Int. J. Osteoarchaeol. (2009) Published online in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/oa.1058 * Correspondence to: Department of Anthropology, University of Tennessee, 250 South Stadium Hall, Knoxville, TN 37996-0720, USA. e-mail: kgodde@utk.edu Copyright # 2009 John Wiley & Sons, Ltd. Received 18 July 2008 Revised 13 November 2008 Accepted 14 November 2008