Efficiency of cranial bilateral measurements in separating human populations

A set of 31 nonconventional paired cranial measurements, as well as six conventional nonpaired measures, were taken on 266 skulls, representing two related populations: Bedouins of the Israeli Negev Desert and Bedouins of the Sinai. The data were subjected to univariate and discriminant analyses to determine the relative efficacy of paired vs. conventional measures in sorting individuals according to tribal and sex affiliation. It was found that paired measures have greater discriminatory power (87%) than conventional ones (47%) in terms of classifying individuals belonging to human isolates derived from a common ancestor and sharing similar environmental conditions. This greater discrimination attests to the value of the level of "developmental noise" (a measure provided by fluctuating asymmetry) in sorting human populations. Possible explanations are proffered for the above finding.