(a) Examine critically the concept of social stratification as a basis for sustaining social inequality. 20 marks (b) Describe…

Social inequality refers to the uneven distribution of valued goods, power, and prestige across individuals, whereas social stratification is the institutionalized, structural hierarchy that groups populations into ranked strata. Stratification serves as the operational matrix that sustains inequality across generations.

Social Stratification and Inequality

Max Weber’s social closure theory demonstrates how dominant groups monopolize opportunities through exclusionary barriers such as endogamy, legal codes, and credentialism. In ascriptive systems, hierarchy is naturalized, locking individuals into predetermined socio-economic tiers.

The functionalist view (Davis-Moore thesis) argues that stratification is universally necessary to ensure that the most qualified individuals fill functionally vital roles via differential rewards. However, conflict theorists (Karl Marx, Max Weber) expose stratification as a socially constructed apparatus of exploitation. Marx highlighted that control over the means of production generates asymmetric power, while Weber demonstrated how the interplay of class, status, and party cements dominance.

In India, the caste (jati) system institutionalized hierarchy through ritual purity-pollution norms, occupational closure, and hereditary status. Despite constitutional interventions (Articles 15, 16, 17) and affirmative action policies like OBC reservations following the Mandal Commission case (Indra Sawhney, 1992), empirical reality shows a persistent class-caste overlap. Dalits and lower castes remain disproportionately concentrated in informal and low-wage labour. Thus, rather than being an inevitable functional meritocracy, stratification is an entrenched, constructed system that legitimizes and perpetuates systemic inequality.

Genetics of ABO and Rh Blood Groups

The ABO blood group system is governed by a polymorphic gene locus on chromosome 9 (9q34.2) exhibiting multiple allelism with three major alleles: I^A, I^B, and i. Alleles I^A and I^B encode specific glycosyltransferases that add N-acetylgalactosamine and D-galactose, respectively, to the precursor H-substance. The i allele is non-functional.

The alleles I^A and I^B exhibit codominance with each other, and both are completely dominant over the recessive i allele. Consequently, six possible genotypes yield four distinct phenotypes: genotypes I^A I^A and I^A i produce Type A; I^B I^B and I^B i produce Type B; I^A I^B produces Type AB; and the homozygous recessive genotype ii produces Type O. Under standard Mendelian segregation, a cross between heterozygous parents (I^A i × I^B i) yields a phenotypic ratio of 1 A : 1 B : 1 AB : 1 O.

The Rh system, located on chromosome 1, is primarily determined by the presence or absence of the D antigen. Inheritance follows simple dominant-recessive Mendelian patterns: genotypes DD and Dd are Rh-positive, while homozygous recessive dd is Rh-negative.

Clinically, maternal-fetal Rh incompatibility occurs when an Rh-negative mother carries an Rh-positive fetus. Sensitization during delivery leads to maternal anti-D IgG production, which can cross the placenta in subsequent Rh-positive pregnancies, causing hemolytic disease of the newborn (erythroblastosis fetalis). In population genetics, polymorphic frequencies of ABO and Rh alleles serve as classical anthropogenetic markers to assess microevolutionary trends, genetic drift, and population affinities.

Biocultural Evolution and Synergism

Human evolution is characterized by gene-culture coevolution (Durham; Boyd and Richerson), where biological and cultural processes act as mutually reinforcing selective forces. Early cultural developments, such as the manufacture of Oldowan stone tools and the control of fire for cooking (Richard Wrangham’s cooking hypothesis), softened diets and expanded metabolic intake, which relaxed selection for large masticatory structures and facilitated encephalization.

A classic genetic demonstration of this synergism is lactase persistence. The cultural innovation of cattle pastoralism and dairying created strong positive selection for regulatory mutations in the LCT gene, allowing adult lactose digestion in pastoralist populations.

Rather than culture decoupling humanity from natural selection, cultural environments actively steer biological adaptation. In the Indian context, the high-altitude Ladakhi population displays genetic adaptations in hypoxia pathways (EPAS1, EGLN1) alongside cultural practices such as specialized housing and yak pastoralism. Similarly, the indigenous Andamanese phenotype (pygmyism/short stature) represents an adaptive biocultural response optimized for thermoregulation in tropical insular habitats.

Human variation must therefore be evaluated as an integrated continuum: biological traits like blood group polymorphisms and biocultural adaptations emerge to optimize human survival, whereas social stratification remains a cultural construction designed to institutionalize power differentials.