Asymmetry of finger ridge countsamong four tribal populations of Andhra Pradesh, India

The asymmetry among the four tribal populations Dulia, Kotia, Manne Dora and Manzai Mali is reported. The mean directional asymmetry (MDA) and mean absolute asymmetry (MAA) were measured for homologous fingers. The asymmetry follows a decreasing trend in radio-ulnar direction with higher mean values in thumb and index finger. The individual variation is also higher in these fingers. Neither sexual nor population differences are consistent. Jantz's Square root of A2 (another measure to assess asymmetry) for total finger ridge count and absolute finger ridge count does not indicate any significant sexual or ethnic differences. The results suggest that the underlying mechanisms influencing the level of asymmetry may be similar for all groups, and that certain dermatoglyphic areas like the thumb are more vulnerable to developmental/environmental stress, that cause asymmetry at the developmental stage.