Genetics of Castes and Tribes of India

Email

Whatsapp

Facebook

Pinterest

Twitter

Copy link

India is a country with enormous social and cultural diversity due to its positioning on the crossroads of many historic and pre-historic human migrations. The hierarchical caste system in the Hindu society dominates the social structure of the Indian populations. The origin of the caste system in India is a matter of debate with many linguists and anthropologists suggesting that it began with the arrival of Indo- European speakers from Central Asia about 3500 years ago. Previous genetic studies based on Indian populations failed to achieve a consensus in this regard. We analysed the Y-chromosome and mitochondrial DNA of three tribal populations of southern India, compared the results with available data from the Indian subcontinent and tried to reconstruct the evolutionary history of Indian caste and tribal populations. No significant difference was observed in the mitochondrial DNA between Indian tribal and caste populations, except for the presence of a higher frequency of west Eurasian-specific haplogroups in the higher castes, mostly in the north western part of India. On the other hand, the study of the Indian Y lineages revealed distinct distribution patterns among caste and tribal populations. The paternal lineages of Indian lower castes showed significantly closer affinity to the tribal populations than to the upper castes. The frequencies of deep-rooted Yhaplogroups such as M89, M52, and M95 were higher in the lower castes and tribes, compared to the upper castes. The book is intended not only for undergraduate and postgraduate students of biotechnology, genomics and related sciences, but is also aimed to draw attention of policy makers and teachers at national and international levels to the possible approaches in the field of biotechnology.

Rameshwar Singh has done his Master degree from Veer Kunwar Singh University, Arrah. At this time he is Lecturer in the Department of Political Science at Patliputra University, Patna. He has attended many national and international seminars. His several research papers have been published in reputed journals.

India is a country with enormous social and cultural diversity due to its positioning on the crossroads of many historic and pre-historic human migrations. The hierarchical caste system in the Hindu society dominates the social structure of the Indian populations. The origin of the caste system in India is a matter of debate with many linguists and anthropologists suggesting that it began with the arrival of Indo. European speakers from Central Asia about 3500 years ago. Previous genetic studies based on Indian populations failed to achieve a consensus in this regard. We analysed the Y-chromosome and mitochondrial DNA of three tribal populations of southern India, compared the results with available data from the Indian subcontinent and tried to reconstruct the evolutionary history of Indian caste and tribal populations. No significant difference was observed in the mitochondrial DNA between Indian tribal and caste populations, except for the presence of a higher frequency of west Eurasian-specific haplogroups in the higher castes, mostly in the north western part of India. On the other hand, the study of the Indian Y lineages revealed distinct distribution patterns among caste and tribal populations. The paternal lineages of Indian lower castes showed significantly closer affinity to the tribal populations than to the upper castes. The frequencies of deep-rooted Y haplogroups such as M89, M52, and M95 were higher in the lower castes and tribes, compared to the upper castes. The first humans to arrive on the Indian subcontinent from Africa about 65,000 years ago left a genetic imprint that can still be found in the tribes of India. Anthropologists have long argued over the genetic makeup of the country's population, because of its complex history of migrations and movement. The first humans to people the sub-continent came from Africa, following the so-called southern route, along the tropical coast of the Indian Ocean.

The tribes speaking Indo-European languages, for instance, are known to be descendants of the people who migrated into India relatively recently from Central Asia and the Caucasus. It was also thought that the Austro-Asiatic speakers were direct descendants of the original settlers. To determine which groups can trace their ancestry to the founding population of India, Vadlamudi Raghavendra Rao of the Anthropological Survey of India in Kolkata and his colleagues analysed 2768 samples of mitochondrial DNA taken from 24 tribes all over India. Mitochondrial DNA is inherited from the mother, so can be used to trace the maternal lineage of a population. The researchers looked for a particular set of mutations in the mitochondrial genome called the M2 haplogroup. This set of genetic markers is unique to India and is a sub-lineage of the M haplogroup that identifies the first humans who arrived in India from Africa 65,000 years ago. The analysis showed that the M2 lineage began in India about 50,000 years ago, about 15,000 years after modern humans arrived. The team also found that the M2 lineage and its branches made up nearly 10% of the mitochondrial DNA of the studied tribes. Significantly, the M2 lineage cuts across major linguistic barriers. The new study shows that both the Dravidian and Austro-Asiatic language groups share these same genetic markers. Upper castes are thought to be the outcome of the arrival over time of a more technologically advanced people that marginalised the indigenous population, starting about 10,000 years ago. Even these new migrants assimilated into India and to some extent mixed with the population, as the presence of M2 genes in the group attests. The early settler component is not restricted to one particular language family, or one particular population. Biologically, there are no castes and tribes, there are only communities.

The book is intended not only for undergraduate and postgraduate students of biotechnology, genomics and related sciences, but is also aimed to draw attention of policy makers and teachers at national and international levels to the possible approaches in the field of biotechnology.

**Contents and Sample Pages**