Original scientific paper
Patterns of Variation in a Caste-Cluster of Dhangars of Maharashtra, India
B. M. Reddy
D. A. Demarchi
K. C. Malhotra
Abstract
We study patterns of variation among the 20 endogamous groups of Dhangars, a
caste-cluster from Maharashtra State of India, who are semi-nomadic shepherds and
cattle herders. To understand patterns of variation, we subjected the data on fourteen
anthropometric measurements of about 2,500 adult males and data on 6 genetic markers,
published among 13 of the 20 Dhangar castes, to R-matrix analysis, Harpending
and Ward model of regression of heterozygosity on the distance from centroid of the populations,
spatial autocorrelation analysis and Mantel statistics of matrix correspondence
of the distances – geographic, anthropometric and genetic. Results of multiple regression
analysis suggest a high degree of association between allele frequencies and the
geographic longitude and latitude; R2 value suggests that about 70% of the variance in
RH7 and ACP can be assigned to geographic distribution of groups. In case of anthropometry,
this association with body size is found to be even stronger. Results of spatial
autocorrelation analysis, as suggested by Moran’s (I), are somewhat complementary to
those based on multiple regression analysis. Mantel test indicates significant association
between anthropometric distances and the geographic distances, not between geographic
and genetic distances. The extent of differentiation of Dhangar sub-castes is
much higher in anthropometric traits (FST = 0.068) when compared to the genetic markers
(FST = 0.023). Yet, the FST value obtained for genetic markers is larger than the average
for the Indian populations, based on similar class of markers. The positioning of the
groups in the multivariate space reflects primarily geographic proximity of the groups
with reference to anthropometric dimensions while no tangible pattern is evident for genetic
markers. The plot of average heterozygosity of the groups versus their distance
from the gene frequency centroid seems to reflect population size variation, rather thangroup
variation in external gene flow.
Keywords
Hrčak ID:
28419
URI
Publication date:
17.12.2001.
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