Dermatoglyphics of inhabitants of Alberche/Tormes valley (Sierra de Gredos-Central Spain): I. Finger pattern types...

The incidence of dermatoglyphic finger patterns and pattern intensity in a sample of school children from the Alberche/Tormes valley (northern slope of the Sierra de Gredos, Central Spain) are described. Significant bilateral differences for the overall finger pattern incidence are found in both sexes. The differences between sexes are also statistically significant, except for the left hand. The Pattern Intensity Index significantly differs between hands of males only, and the sex differences are not significant. Variation ranges for fingertip patterns and pattern intensity were constructed using published data of 69 male and 62 female series drawn from the whole of the Iberian Peninsula. The overall incidence of fingertip patterns and the Pattern Intensity Index locate the studied population near the middle of the corresponding variation ranges. The only exception is the case of arches, for which Alberche/Tormes is close to the minimum value of the range of variation. A more detailed comparison of 10 male and 10 female series from the Spanish northern and southern plateaus and from the Spanish region of Extremadura was done with R-matrix analysis. The series compared include those from the northern slope (Alberche/Tormes valley, this study) and the southern slope (Tiétar valley) of the Sierra de Gredos. The observed degree of dermatoglyphic differentiation between these two series may be explained by taking into account both the role of the Sierra de Gredos as a biological barrier limiting gene flow and the evolutionary stability of dermatoglyphics. © 1996 Wiley-Liss, Inc.