Microevolution Among the Yanadi Tribe: Population Structure and Sex Differences in Anthropometric and Dermatoglyphic Characters

Abstract

Microevolutionary trends in anthropometric and quantitative dermatoglyphic traits have been investigated among the five regional populations of the Yanadi tribe, who live in different regions and differ in their life style and population structural variables. Of the five, CY and IY live as hunters-gatherers in coastal areas where as rest three P1, HF and P2 survive as agricultural labourers and agricultural landholders in hill-forest (HF) and plateau regions (P1, P2) in three districts in Andhra Pradesh. The regional differences in some of the population structure variables; viz., marriage pattern, inbreeding etc., observed among the regional populations indicate the possibility of microevolutionary trends. This has been investigated in case of morphology and dermatoglyphics traits. The results show significant differences both in size and shape components of morphology and in some of the quantitative characters e.g., triradial numbers, finger ridge count and in pattern combination indices among the regional populations. The CY and IY coastal populations differ from the three inland populations of pre-agricultural and agricultural populations. The results show that males and females within a regional population are more similar in their morphology and dermatoglyphic traits than when compared with their counter parts in other regional populations. The dendrograms show consistency in the clustering pattern and also show differences between males and females, which is in agreement with the expectation based on population structure variables. The pattern combination analysis (PCA) shows significant differences in some of the pattern combination types of monmorphic and trimorphic pattern types (PCT-tr) and significant sex differences in quantitative PCA method where females show the absence of tertramorphic pattern ratios.