Craniofacial asymmetry in Bedouin adults.

The directional and fluctuating asymmetry characteristics of the human skull with reference to demographic and genetic parameters are presented. In addition, the discriminatory ability (in sex, age, and tribal origin) of asymmetry variables was evaluated against a battery of conventional metric measures. Regarding directional asymmetry (DA), the results show that the calvarium exhibits a clear right-sided "excess" and the basal region a left-sided "excess." The DA of traits of the face appears ambiguous. Age and sex evidently have no bearing on DA, whereas tribal origin does. In fluctuating asymmetry (FA), the effect of age is negligible; sex is a factor, albeit to a minor extent. The facial region manifests the highest mean FA value and the calvarium the lowest. The more a skull deviates metrically from the population mean, the higher the mean FA value. FA and DA measures show a relatively low intercorrelation (<0.20). Comparison of the discriminatory ability (F = 1, F = 4) of asymmetry vs. metric measures shows that the former are better classifiers of tribal affiliation, whereas the latter discriminate better between the sexes.