Anthropology, Texas State University-San Marcos
Saturday All day, Plaza Level
Variation in sexual dimorphism is related to average body size differences and limb proportions within males and females in a particular population (Charisi et al., 2011). Theory suggests that expression of sexual dimorphism relies on male susceptibility to impairment in long bone length during episodes of stress, while females are “buffered” from the same conditions due to reproductive demands (Frayer and Wolpoff, 1985). This study evaluates the degree of sexual dimorphism between three populations in an attempt to examine different stress factors affecting individuals within and between migrant and non-migrant populations. The sexual dimorphism index (SDI) was calculated for long bone lengths in American White individuals from the Forensic Anthropology Data Bank (n=93), a migrant group of U.S. - Mexico border crossing fatalities from Tucson, Arizona (n=152), and a non-migrant Mexican group from Zimapan, Hidalgo (n=43). The SDI results demonstrate similar dimorphic levels between the modern American White and non-migrant Hispanic sample, while the migrant population shows lower dimorphic levels. Multivariate analysis also indicates significant degrees of sexual dimorphism between the three samples. Migrants that enter the United States via the Arizona border are thought to come from low-income areas (Duran and Douglas, 1992). Potential explanations for the differing degrees of sexual dimorphism can be attributed to the interaction of socioeconomic status, division of labor, work load, and the environment. Furthermore, the different levels of sexual dimorphism observed between American Whites and the migrant group demonstrates the need for population specific methods of sex estimation.