Dermatoglyphic Variation Among Sub- Saharan Africans: A Multivariate Analysis of Population Structure

It has been previously observed that population structure analysis using dermatoglyphics tends to follow Similar patterns formed by other biological features (serology, craniometric, anthropometrics), and reflect relevant linguistic or geographical distributions. But the level of these correlations has not been consistantly identified, causing some debate over the validity of dermatoglyphics as a form of study in human populations. A systematic analysis of a series of populations needs to be made to evaluate how well dermatoglyphic variables generate significant genetic, cultural and geographical relationships between groups, and which particular dermatoglyphic features best present these population affinities.

Using multivariate statistical methods, the five most widely employed dermatoglyphic techniques are tested for their ability to present understandable population structure. Complete 20 finger ridge-counts, 10 finger ridge-counts, palmar interdigital ridge-counts, finger pattern frequencies and palmar pattern frequencies, following standard methods, were obtained for 50 African tribal populations.

Mahalanobis D-square distance matrices were generated for each of the dermatoglyphic data sets and tested for significance by canonical analysis. Principal coordinate plots were used to visualize patterns of geographical, biological or cultural affinity present in the distributions. D-square matrix correlations between the dermatoglyphic distance and the linguistic and geographical distance matrices were produced to quantify shared information between the dermatoglyphic data sets.

Results from this study reaffirm the multidimentiality of dermatoglyphics illustrated by the variation in ridge-count and pattern frequency distributions. Although all the tested dermatoglyphic techniques produced some level of group relationship, the use of all 20 finger ridge-counts produced the best representation of geographic and biological group associations. Distance relationships between dermatoglyphic methods and linguistic affinities were Significant, supporting previous findings along these lines. Geographical distributions were marginally significant only in the finger ridge-count variables. Group relationships present in this study agree with the Bantu expansion hypotheses’ for Western population migrations into Southern regions late in African prehistory. The agreement with these hypotheses and other biological distributions of African populations substantiate dermatoglyphics as a viable research method for evaluating biological aspects of population structure analysis.