Indian Caste Groups Research Articles

Ethnic dominance damages cooperation more than ethnic diversity: results from multi-ethnic field experiments in India

Research in many societies shows that ethnic diversity correlates with a decline in cooperation at the community level. This literature neglects cases in which ethnic heterogeneity is hierarchically structured. Power and status differences between ethnic groups, or ethnic dominance, may play an important role in determining cooperative outcomes. We test this hypothesis using public goods experiments with caste groups in India in which we manipulate the caste composition of experimental groups. Conservative estimates show that ethnic dominance between high and low ranking castes has a much larger negative effect on contributions in the public goods experiment than does caste diversity. We argue that ethnic dominance interactions such as ethnic discrimination constitute a type of antisocial punishment between groups. We also find that conditional cooperation is limited to within ethnic groups, revealing ethnocentric cooperation preferences. These results confirm the importance of group structure in human cooperative patterns, and help bridge the gap between evolutionary theory and cooperation dynamics in multi-ethnic real world settings.

Presence of three different paternal lineages among North Indians: A study of 560 Y chromosomes

Background: The genetic structure, affinities, and diversity of the 1 billion Indians hold important keys to numerous unanswered questions regarding the evolution of human populations and the forces shaping contemporary patterns of genetic variation. Although there have been several recent studies of South Indian caste groups, North Indian caste groups, and South Indian Muslims using Y-chromosomal markers, overall, the Indian population has still not been well studied compared to other geographical populations. In particular, no genetic study has been conducted on Shias and Sunnis from North India.Aim: This study aims to investigate genetic variation and the gene pool in North Indians.Subjects and methods: A total of 32 Y-chromosomal markers in 560 North Indian males collected from three higher caste groups (Brahmins, Chaturvedis and Bhargavas) and two Muslims groups (Shia and Sunni) were genotyped.Results: Three distinct lineages were revealed based upon 13 haplogroups. The first was a Central Asian lineage harbouring haplogroups R1 and R2. The second lineage was of Middle-Eastern origin represented by haplogroups J2*, Shia-specific E1b1b1, and to some extent G* and L*. The third was the indigenous Indian Y-lineage represented by haplogroups H1*, F*, C* and O*. Haplogroup E1b1b1 was observed in Shias only.Conclusion: The results revealed that a substantial part of today's North Indian paternal gene pool was contributed by Central Asian lineages who are Indo-European speakers, suggesting that extant Indian caste groups are primarily the descendants of Indo-European migrants. The presence of haplogroup E in Shias, first reported in this study, suggests a genetic distinction between the two Indo Muslim sects. The findings of the present study provide insights into prehistoric and early historic patterns of migration into India and the evolution of Indian populations in recent history.

HLA‐B27 polymorphism in Mumbai, Western India

Human leucocyte antigen (HLA)-B27 encompasses an increasing number of subtypes that show diverse racial/ethnic prevalence in the world. One thousand-one-hundred and seventy unrelated individuals from Mumbai, Maharashtra, Western India were typed for HLA-B27 antigen by serological methods. HLA-B27 positivity was confirmed by polymerase chain reaction using sequence specific primers. High-resolution typing using sequence specific primers for HLA-B27 alleles (B*2701 - B*2721) was carried out in 70 HLA-B27-positive individuals. The frequency of B27 ranged between 1.48 and 9.6% among the caste groups studied. HLA-B27 subtyping identified B*2702 (1.43%), B*2704 (14.29%), B*2705 (70%), B*2707 (12.86%) and B*2718 (1.43%), respectively. The findings illustrate substantial genetic variation and heterogeneity within population groups from India. Extensive subtyping in other Indian caste groups will be necessary to resolve the evolutionary implications of HLA-B27 subtypes and their relationship to disease association in the Indian context.

HLA DRB1* and DQB1* allelic diversity among nadars: A primitive South Indian Dravidian caste group

South India is one of the oldest geophysical regions occupied mainly by Dravidian language-speaking people. In the present study, 84 unrelated healthy Nadar individuals from Tamil Nadu State were analyzed for human leukocyte antigen (HLA) DRB1* and DQB1* allele frequencies and their haplotype frequencies were analyzed by high resolution polymerase chain reaction (PCR)-typing of genomic DNA. Results revealed that Nadars possessed >0.1 allele frequencies of HLA DRB1*15011, 03, 04, 1404, 0701, 1001, and DQB1*0201, 03, 0501, and 0503. The highest frequencies of DRB1*0317 (0.048), DRB1*1317 (0.012), and DRB1*1404 (0.107) in the world were found among the Nadar caste. The most frequent two-locus haplotypes identified among the Nadars were DRB1*0701–DQB1*0201 and DRB1*1000–DQB1*0501, and DRB1*1404–DQB1*0503 and DRB1*15011–DQB1*0601. When compared with world populations, HLA DRB1*1322, DRB1*1434, and DQB1*0614 were identified exclusively among Nadars. The heterozygosity and Watterson's homozygosity tests indicated that balancing selection still operates among the South Indian caste groups. The hierarchical cluster analysis for DRB1 data from the Indian caste and population groups showed that the Nadars cluster with Kashmir Brahmins and North Indians. The present study shows that the Nadar caste has several unique alleles and haplotypes at high frequency that are rare or absent in other populations of India and the world.

Diversity Among Selected Caste and Tribal Groups of Western India: Origin, HLA and Disease Associations

KEYWORDS Caste groups; tribal groups; HLA antigens; disease associations ABSTRACT Indian population is well known for its genetic diversity. Among the numerous endogamous communities, which is restricted very much by custom, marriage and occupation, a compiled analysis of 1742 individuals comprising of different caste and tribes from Maharastra Western India is presented. The sympatrically isolated caste and tribal population of western India with different origins, migration pattern and breeding habits differed significantly in their HLA and also in their HLA allele (Relative risk) prevalence for a number of disease associations. Further the analysis reveal that the caste groups of India cannot be considered as a single panmictic population with reference to genetic characteristics, which may have a clinical relevance in unrelated donor selection for allogenic Bone marrow transplantation and disease associations in India.

HLA Antigen Distribution in Selected Population Groups from Maharashtra

Indian population is well known for its genetic diversity. Among the numerous endogamous communities, which are restricted very much by custom, marriage and occupation we have collected 195 unrelated individuals, belonging to Marathi, Gujarathi, Punjabi, South Indian, Christian and Muslim population groups. We present here the HLA- A, B, and C locus antigen distribution of these population groups compared with each other. The HLA antigens were identified by using the standard complement mediated NIH microlymphocytotoxicity assay. The results revealed that HLA A1, A2, A3, A11, A24, B5, B35, B40, B44, Cw4 and Cw7 were the most frequent alleles while HLA A28, A36, A69, B14, B16, B38, Cw2 and Cw8 were the less frequent alleles represented in all the populations studied. Further, HLAA30, A36, A69, B50 and B55 alleles were observed among the Punjabis, A29 and B62 among the Gujarathi population, High frequencies of HLAB5 and Cw4 among the South Indians as well as rare allelic splits like A23 among the amalgamated Christians were also observed. The study reveals that the population or caste groups in India cannot be considered as a single panmictic population with reference to HLA genetic characteristics, which may have a clinical relevance in unrelated donor selection for allogenic bone marrow transplantation in India.

Independent Origins of Indian Caste and Tribal Paternal Lineages

The origins of the nearly one billion people inhabiting the Indian subcontinent and following the customs of the Hindu caste system are controversial: are they largely derived from Indian local populations (i.e. tribal groups) or from recent immigrants to India? Archaeological and linguistic evidence support the latter hypothesis, whereas recent genetic data seem to favor the former hypothesis. Here, we analyze the most extensive dataset of Indian caste and tribal Y chromosomes to date. We find that caste and tribal groups differ significantly in their haplogroup frequency distributions; caste groups are homogeneous for Y chromosome variation and more closely related to each other and to central Asian groups than to Indian tribal or any other Eurasian groups. We conclude that paternal lineages of Indian caste groups are primarily descended from Indo-European speakers who migrated from central Asia approximately 3,500 years ago. Conversely, paternal lineages of tribal groups are predominantly derived from the original Indian gene pool. We also provide evidence for bidirectional male gene flow between caste and tribal groups. In comparison, caste and tribal groups are homogeneous with respect to mitochondrial DNA variation, which may reflect the sociocultural characteristics of the Indian caste society.

HLA Antigen Distribution in Selected Gujarati Subcaste from Mumbai, Maharastra, India

Indian population is well known for its genetic diversity. Among the numerous endogamous communities, which are restricted very much by cus- tom, marriage and occupation we have collected 178 unrelated Gujarati speaking individuals, belonging to Lohanas, Banyas and Gujarati Brahmins caste groups. We present here the HLA- A, B, C and DR locus antigen distribution of these endogamous caste groups compared with each other. The HLA antigens were identified by using the standard complement mediated NIH microlymphocytotoxicity assay. The phenotypic fre- quencies of HLA- A2, A9, B5, B35, B40, DR2, DR3 in Banyas, A10, A19, B8, B17, Cw3, DR7 in Lohanas and A1, B7, B22, Cw5, DR1 in Gujarati Brahmins were found to be significantly increased. The phenotype frequen- cies of A10, B13, DR6 in Banyas, B15, B22, DR4 in Lohanas and A2, A10, B8, B13, B37, Cw7, DR6 in Gujarati Brahmins were found to be significantly de- creased among the HLA antigens tested. Haplotype analy- sis revealed that A33-B44-DR7 haplotype were present in all the three caste groups while, A1-B17 in Brahmins, A11-B35, A2-B5, A3-B18 in Lohanas and A11-B62, A3-B40 in Banyas were unique among the caste groups. Haplotype A24-B5 was identified among Lohanas and Banyas. The observed antigen frequencies and linkage disequilibrium among the three Gujarati caste groups sug- gest the influence of genetic drift caused by selection, geography and culture. The study also reveals that the caste groups in India cannot be considered as a single panmictic population with reference to genetic charac- teristics, which may have a clinical relevance in unre- lated donor selection for allogenic bone marrow trans- plantation in India.

The Genetic Heritage of the Earliest Settlers Persists Both in Indian Tribal and Caste Populations

Two tribal groups from southern India--the Chenchus and Koyas--were analyzed for variation in mitochondrial DNA (mtDNA), the Y chromosome, and one autosomal locus and were compared with six caste groups from different parts of India, as well as with western and central Asians. In mtDNA phylogenetic analyses, the Chenchus and Koyas coalesce at Indian-specific branches of haplogroups M and N that cover populations of different social rank from all over the subcontinent. Coalescence times suggest early late Pleistocene settlement of southern Asia and suggest that there has not been total replacement of these settlers by later migrations. H, L, and R2 are the major Indian Y-chromosomal haplogroups that occur both in castes and in tribal populations and are rarely found outside the subcontinent. Haplogroup R1a, previously associated with the putative Indo-Aryan invasion, was found at its highest frequency in Punjab but also at a relatively high frequency (26%) in the Chenchu tribe. This finding, together with the higher R1a-associated short tandem repeat diversity in India and Iran compared with Europe and central Asia, suggests that southern and western Asia might be the source of this haplogroup. Haplotype frequencies of the MX1 locus of chromosome 21 distinguish Koyas and Chenchus, along with Indian caste groups, from European and eastern Asian populations. Taken together, these results show that Indian tribal and caste populations derive largely from the same genetic heritage of Pleistocene southern and western Asians and have received limited gene flow from external regions since the Holocene. The phylogeography of the primal mtDNA and Y-chromosome founders suggests that these southern Asian Pleistocene coastal settlers from Africa would have provided the inocula for the subsequent differentiation of the distinctive eastern and western Eurasian gene pools.

HLA-B27 allele diversity in Indians: impact of ethnic origin and the caste system

HLA-B27 is a serological specificity which encompasses an increasing number of subtypes that show varied racial/ethnic prevalence in the world. Here, data from 5129 Indians (4500 population and caste; 629 tribal) is compiled from the literature. In addition, HLA-B27 subtyping of 58 positive individuals from Maharastra is presented. Analysis revealed an increased B27 antigen frequency among the north Indian groups (>5%) compared to the south Indian groups (<5%). HLA-B27 subtyping identified B*2704 (34.48%), B*2705 (36.2%), B*2707 (15.51%), B*2708 (10.34%) and B*2714 (3.44%) alleles in the population groups from Maharastra, but these differed in their distribution among the caste and tribal groups studied. The study showed that more extensive subtyping in other Indian caste groups will be necessary to resolve the evolutionary implications of HLA-B27 subtypes and their relationship to disease association in the Indian context.

Genetic profile based upon 15 microsatellites of four caste groups of the eastern Indian state, Bihar

Background: The formation of caste groups among the Hindu community and the practice of endogamy exert a great impact on the genetic structure and diversity of the Indian population. Allele frequency data of 15 microsatellite loci clearly portray the genetic diversity and relatedness among four socio-culturally advanced caste groups: Brahmin, Bhumihar, Rajput and Kayasth of Caucasoid ethnicity of Bihar. Aim: The study seeks to understand the impact of the man-made caste system on the genetic profile of the four major caste groups of Bihar. Methods and procedure: Computation of average heterozygosity, most frequent allele, allele diversity and coefficient of gene differentiation (Gst), along with genetic distance (DA) and principal coordinate analysis were performed to assess intra-population and inter-population diversity. Main outcomes and results: The average Gst value for all the loci was 0.012 ± 0.0033, and the level of average heterozygosity was ˜75.5%, indicating genetic similarity and intra-population diversity. Genetic distance (DA) values and the phylogenetic tree along with other higher caste groups of India indicate the relative distance between them. Conclusion: The present study clearly depicts the genetic profile of these caste groups, their inherent closeness in the past, and the impact of the imposed caste system that later restricted the gene flow. The study highlights the status of Bhumihar and Kayasth in the Hindu caste system. The former was found clustering with the Brahmin group (as expected, since Bhumihar is known to be a subclass of Brahmin), whereas the distance between the Brahmin and Kayasth caste groups was found to be large. North-eastern Indian Mongoloids form a separate cluster.

Founder effects explain the distribution of the HLAA1-B17 but not the absence of theA1-B8 haplotypes in India

The HLA system may play an important role in natural selection processes through its involvement in immune response and because of the HLA association of some diseases. Linkage disequilibrium in the HLA system poses many interesting questions. India. a melting pot of races and cultures in sympatric isolation, provides an ideal opportunity to study these aspects. Linkage disequilibrium and haplotype data are valuable in the comparison of various populations. An analysis of the available HLA A-B haplotype data for the Indian population documents the heterogeneous nature of the latter: each endogamous caste group, major group or even regional group has its characteristic haplotype profile. The haplotypeA1-B17 is present in most Indian populations butA10-B8 occurs mostly in North India: this may be a consequence of founder effects. The haplotypeAl-B8 a typical Caucasian haplotype, is absent in the Indian subcontinent: this may be due to the selective disadvantageA1-B8 confers in the Indian environment. The different regional and caste groups of India possessing diverse haplolype combinations provide an ideal opportunity to evaluate the selective values of these haplotypes and to study human immunogenetics.

Consanguineous marriages and marriage payment: a study among three south Indian caste groups.

The present study aims at understanding the interrelations between consanguineous marriages and marriage payment. The data are collected from three castes inhabiting two regions of Nellore district, Andhra Pradesh, South India. It is evident from the study that the dowry system is more prevalent among higher castes, while the bride wealth system is more common among the lower castes in the hierarchy. Further, it can be seen that the dowry system is more prevalent in developed regions, while bride-wealth is more common in backward regions. Marriage payment is found to be less common in close kin marriages than in unrelated marriages. Most of the uncle-niece marriages are without any marriage payment, in all the castes. However, most of the matrilateral cross-cousin and patrilateral cross-cousin marriages are also without any marriage payment in the Devanga.

Social Perception of Ingroup and Outgroup Members in India.

One hundred male undergraduates, members of five caste groups in India, evaluated members of their own caste group, religious group, and other religious groups. Allport's prediction that we all define ingroup on the basis of a narrow criterion was contrasted with Paranjpe's prediction that position of a group within a societal framework determines the criterion of defining ingroup. It was found that Ss coming from the upper part of the social continuum defined their ingroup on the basis of caste, as Allport predicts. Ss coming from the lower part of the continuum, however, defined ingroup on the basis of religion consistent with the prediction of Paranjpe. It was, therefore, concluded that the bases of ingroup feelings among the members of a society vary with their position within the societal framework. Furthermore, the ethnocentrism theory of Paranjpe provides a better account for ingroup feelings than that of Allport.

Phenylthiocarbamide taste threshold distribution among the Rastogis of India.

The PTC taste threshold distribution has been examined among the Rastogis and compared to those of other Indian caste groups of Uttar Pradesh.

Genetical differences in skin tanning capacity

A Philips U. V. lamp (for U. V. irradiations) and an E.E.L. spectrophotometer (for measurement of melanin pigmentation of skin) were used to study the existence of any genetical differences in the skin tanning capacity in the males of four Indian caste groups, namely the Arora, the Baniya, the (bengali) Brahman and the Kayastha (Saxena). It was found that only the Arora and the Baniya show genetical differences in skin tanning capacity while the rest don't.