Unfolding the mystery of human civilisation: How several tribes turned into caste groups

By Syed Akbar

India, with its dozens of populations, presents a veritable museum of
humanity. It is the land of tribals and caste groups, not to speak of the 
numerous religious populations. A little peep into the past and analysis 
of the genetic data of different Indian populations shows that many 
groups, which were originally tribal in nature, have now become caste 
populations. And this transformation from "tribal" to "caste" groups 
may outwardly appear to be a simple sociological phenomenon, but a 
recent study reveals that it has genetic structure too.
The Hyderabad-based anthropology unit of the Indian Statistical 
Institute in its study on north-east Indian populations has established 
the effect of the sociological process of a Tribe-Caste continuum on 
genetic structure.
In north-eastern States of India there are two clusters of populations, 
Caucasoid caste populations on one side and Mongoloid tribal groups 
on the other. In between are the populations which were originally 
tribes but now have become semi-Hinduised caste groups, viz., 
Rajbanshi, Ghutiya, and Ahom. These groups have currently assumed 
caste status and speak Indo-European languages.
According to Dr B Mohan Reddy and Vikrant Kumar of Indian 
Statistical Institute, these tribes over a period of time assumed the 
characteristics and status of castes and this transformation of a tribe 
into a caste results in a Tribe-Caste continuum. A few such cases are 
Bhumij, Kharia, Bauris and Raj Gonds.
"This sociological concept of a Tribe-Caste continuum postulates that 
one end of the continuum is formed by caste populations, while the 
tribal populations constitute the other end. In between are the 
populations who were once tribes but gradually adopted the attributes 
of the caste population and ultimately became absorbed as an integral 
part of a caste system, albeit at the lowest rung of caste hierarchy," they 
point out.
One of the best examples is that of Rajbanshi, which claims to be 
Kshatriya, although a majority of them are Koch. Similar processes 
were reported from other groups such as the Dimasa of Tripura, Jantia 
of Jaintipur and Koch of Cooch Behar. The dwindling of Kachari 
groups from a large number of about 30 to 10 at present is said to be a 
result of this process, they said.  
As part of the study the scientific group examined the gene frequency 
data for 11 genetic markers commonly available in the literature for 22 
populations of north-eastern India in the light of their geographic, 
linguistic, and ethnic affiliations. The markers investigated were blood 
groups, serum proteins and enzyme systems.
The neighbour-joining tree and multidimensional scaling of the 
distance matrix suggest relatively high genetic differentiation among 
the Mongoloid groups, with probably diverse origins when compared 
to the Caucasoid Indo-European populations, which had probably come 
from relatively more homogeneous backgrounds. Broadly speaking, the 
pattern of population affinities conforms to the ethno-historic, 
linguistic, and geographic backgrounds, Dr Mohan Reddy and Vikrant 
Kumar observed. 
The north-eastern part of India is inhabited by numerous endogamous 
tribes and castes that have their own distinct social, linguistic and 
biological identity. It has been hypothesised that a plethora of 
migrations, particularly through the north-east Indian corridor, has 
contributed to the present-day population of north-eastern India. 
Ethnically speaking, most of the tribal groups are Mongoloids, whereas 
caste groups are either Caucasoid or show a mosaic of features of both 
the ethnic groups. The Mongoloids/Indo-Mongoloids have come to 
India from different directions at different times and perhaps earlier 
than the Caucasoid.
While the Mongoloids have migrated from eastern, south-eastern and 
central Asian regions, the Caucasoid may have entered from western 
and northern boundaries of this region. While a majority of the 
Mongoloids are tribes affiliated with the Tibeto-Chinese linguistic 
family, excepting Khasi, most of the Caucasoid are caste groups and 
speak Indo-European languages. Although these groups have been 
broadly classified on the basis of language and ethnicity, they show 
considerable variations within these broad categories, they said.
Both the Mongoloid and Caucasoid groups show a certain degree of 
differentiation within themselves in cultural and biological traits such 
as anthropometry, genetic markers, and dermatoglyphics.
The study also confirms the hypotheses that Mongoloids have entered 
north-eastern India at different points of time by different routes and 
therefore might represent different parental stocks. On the other hand, 
the Caucasoid populations except for the Brahmins and Chetri of 
Sikkim, have migrated from the western route of north-eastern India. 
As far as the Brahmins and Chetri of Sikkim are concerned, they came 
from Northern India to Nepal and then to north-eastern India around 
the 19th century.

Man settled on the picturesque Andaman islands 10,000 to 24,000 years ago and not 45,000 to 50,000 years ago as earlier believed

By Syed Akbar

Hyderabad: Man settled on the picturesque Andaman islands 10,000 to 24,000 years ago and not 45,000 to 50,000 years ago as earlier believed.

Research studies based on population genetics by the Anthropological Survey of India showed that human settlement on Andaman islands was a relatively recent phenomenon, 24,000 years old at the most. This negates the popular belief that early humans migrated from Africa between 45,000 and 50,000 years ago and settled in Andamans before fanning out to other places including Myanmar and India.

Anthropological Survey of India director-in-charge Dr VR Rao told this correspondent that "the migration of people to Andaman islands took place tentatively around 24,000 years ago." The ASI scientists came out with the observation following an investigation of deep structure of mitochondria DNA sub groups M31, which is Andaman specific and M32 which is India specific. They used whole-genome sequencing methods as part of the study.

The mtDNA contains ancient signature of genes that are passed from mother to child. A study of mtDNA reveals when and how early humans migrated from Africa and settled across the Earth.

India, because of its strategic location on the proposed corridor of human movement from Africa to Australia, holds the key to the understanding of early human prehistory. Genetic studies conducted earlier, based on mitrochondrial DNA, showed that the relative isolation of the late Pleistocene colonisers, and the physically isolated Andaman Island populations was because of an early split between populations settled along the coast of Indian Ocean.

"The identification of a so far unnoticed rare polymorphism shared between these two lineage suggests that they are actually sister groups within a single haplogroup, M31'32. The enhanced resolution of M31 allows for the inference of a more recent colonisation of the Andaman Islands than previously suggested, but cannot reject the very early peopling scenario," Dr Rao said.

The ASI study further demonstrated a widespread overlap of mtDNA and cultural markers between the two major language groups of the Andaman archipelago. "Given the "completeness" of the genealogy based on whole genome sequences, and the multiple scenarios for the peopling of the Andaman Islands sustained by this inferred genealogy, our study hints that further mtDNA based phylogeographic studies are unlikely to unequivocally support any one of these possibilities," he said.

According to Dr Rao, the significance of the new finding is in terms of understanding the earliest genomic foot prints in the subcontinent. The implications are relevant in evolutionary biology. Adaptive traits which have implications in health and disease and their variation across human populations, can now be in a perspective.
He said the earlier Andamanese were known sea farers. "The story of human migrations is very complex. Even you go to Homo erectus stage, we have very complex scenario of migrations. The question why chimpanzees are not found in Africa is a million dollar question. Nevertheless, imagine all life forms sequencing of whole genomes is available," he said.

Human migration: Early humans did not settle down in India immediately after out of Africa migration

Syed Akbar

Hyderabad: Early human beings did not settle down in India immediately after their famous migration out of Africa. They took nearly 40,000 years before they settled down in India.

According to a new hypothesis on the migration of human beings from Africa and their settling down in Europe and Asia, the divergence among different Eurasian populations occurred more than 40,000 years after their divergence with Africans. Scientists from the University of Utah and the Human Genome Sequencing Centre, Houston, based their observations after re-analysing the genetic material obtained from three castes (Brahmin, Yadava and Mala/Madiga) and one tribe (Irula) from Andhra Pradesh.

The divergence time estimates among the major population groups suggest that Eurasian populations diverged from Africans during the same time frame, about 90,000 to 1,10,000 years ago. But the divergence among different Eurasian populations occurred more than 40,000 years after their divergence with Africans.

"Genetic studies of populations from the Indian subcontinent are of great interest because of India’s large population size, complex demographic history, and unique social structure. Despite recent large-scale efforts in discovering human genetic variation, India’s vast reservoir of genetic diversity remains largely unexplored," one of the researchers Lynn B Jorde said.

According to the researchers, several Indian populations, such as  Yadava, Mala/Madiga, and Irula, have nucleotide diversity levels as high as those of HapMap African populations. "Our data also support a delayed expansion hypothesis in which an ancestral Eurasian founding population remained isolated long after the out-of-Africa diaspora, before expanding throughout Eurasia," he pointed out.

The high diversity and the deep mitochondrial lineage in India support the hypothesis that Eurasia was initially populated by two major out-of-Africa migration routes. Populations migrating along an early “southern-route” originated from the Horn of Africa,

crossed the mouth of the Red Sea into Arabian Peninsula, and subsequently migrated into India, Southeast Asia, and Australia. Later, populations migrated out of Africa along a “northern route”

from northern Africa into the Middle East and subsequently populated Eurasia.

"Overall, these results support a scenario in which the ancestors of the Indian, European, and East Asian individuals left Africa in one major migration event, and then diverged from one another more than 40,000 years later," the research report said.

Regardless of caste affiliation, genetic distance estimates with mitochondrial markers showed a greater affinity of south Indian castes to East Asians, while distance estimates with Y-chromosome markers showed greater affinity of Indian castes to Europeans.

History of prehistoric India: We are not Aryan or Dravidian race. Indians are a genetic mixture of two ancient groups of people, say scientists

2009
By Syed Akbar
Hyderabad, Sept 24: A group of city scientists in collaboration with
international researchers on Thursday debunked the age-old Aryan theory
that states that Aryans are the progenitors of north Indian population. It also
sets aside the Dravidian theory that north Indian and south Indian people are
genetically different.

The present-day north Indian and south Indian populations are a genetic
mixture of what could be called the ancestral south Indian population and the
ancestral north Indian population. The north Indian ancestral group is closely
related to European populations unlike the south Indian ancestral group,
which is distinctly unique.

Ancestral south Indian population and ancestral north Indian population had
married among each other to give raise to the present Indian population,
which is neither Dravidian nor Aryan. "It is a genetic mixture of ASI and
ANI and is quite distinct from the original ancestral groups," points out K
Thangaraj, senior scientists at the city-based Centre for Cellular and
Molecular Biology.

The pioneering research study, conducted jointly by the CCMB, Harvard
Medical School, Harvard School of Public Health and the Broad Institute of
Harvard and MIT, USA, is being claimed as the one "which will rewrite the
Indian anthropological and genetics history".

According to the study, nearly all Indians carry genomic contributions from
two distinct ancestral populations. Following this ancient mixture, many
groups experienced periods of genetic isolation from each other for
thousands of years. It has medical implications for people of Indian descent.

Although the genome sequences of any two unrelated people differ by just
0.1 per cent that tiny slice of genetic material is a rich source of information.
It provides clues that can help reconstruct the historical origins of modern
populations. The research team analysed more than 5,00,000 genetic markers
across the genomes of 132 individuals from 25 diverse groups, representing
13 States, all six language families, traditionally "upper" and "lower" castes,
and tribal groups.

Dr Lalji Singh, co-author of the study, said India is not a nation of one
population. It is a nation of 4635 populations, 532 tribes and 72 primitive
tribes. The original tribal population gave birth to the caste system as it
diverted from forest life to agricultural activity. Caste system in India dates
back to thousands of years and it is not a creation of the British, as is
commonly believed.

The researchers also found that Indian populations were much more highly
subdivided than European populations. But whereas European ancestry is
mostly carved up by geography, Indian segregation was driven largely by
caste. "There are populations that have lived in the same town and same
village for thousands of years without exchanging genes," says co-author
David Reich of Harvard Medical School.

Out of Africa: Andaman tribes just 10,000 year old

February 14, 2008
By Syed Akbar
Hyderabad, Feb 13: Man settled on the picturesque Andaman islands 10,000 to 24,000 years ago and not 45,000 to 50,000 years ago as earlier believed.
Research studies based on population genetics by the Anthropological Survey of India showed that human settlement on Andaman islands was a relatively recent phenomenon, 24,000 years old at the most. This negates the popular belief that early humans migrated from Africa between 45,000 and 50,000 years ago and settled in Andamans before fanning out to other places including Myanmar and India.
Anthropological Survey of India director-in-charge Dr VR Rao told this correspondent that "the migration of people to Andaman islands took place tentatively around 24,000 years ago." The ASI scientists came out with the observation following an investigation of deep structure of mitochondria DNA sub groups M31, which is Andaman specific and M32 which is India specific. They used whole-genome sequencing methods as part of the study.
The mtDNA contains ancient signature of genes that are passed from mother to child. A study of mtDNA reveals when and how early humans migrated from Africa and settled across the Earth.
India, because of its strategic location on the proposed corridor of human movement from Africa to Australia, holds the key to the understanding of early human prehistory. Genetic studies conducted earlier, based on mitrochondrial DNA, showed that the relative isolation of the late Pleistocene
colonisers, and the physically isolated Andaman Island populations was because of an early split between populations settled along the coast of Indian Ocean.
"The identification of a so far unnoticed rare polymorphism shared between these two lineage suggests that they are actually sister groups within a single haplogroup, M31'32. The enhanced resolution of M31 allows for the inference of a more recent colonisation of the Andaman Islands than previously suggested, but cannot reject the very early peopling scenario," Dr Rao said.
The ASI study further demonstrated a widespread overlap of mtDNA and cultural markers between the two major language groups of the Andaman archipelago. "Given the "completeness" of the genealogy based on whole genome sequences, and the multiple scenarios for the peopling of the Andaman Islands sustained by this inferred genealogy, our study hints that further mtDNA based phylogeographic studies are unlikely to unequivocally support any one of these possibilities," he said.
According to Dr Rao, the significance of the new finding is in terms of understanding the earliest genomic foot prints in the subcontinent. The implications are relevant in evolutionary biology. Adaptive traits which have implications in health and disease and their variation across human populations, can now be in a perspective.
He said the earlier Andamanese were known sea farers. "The story of human migrations is very complex. Even you go to Homo erectus stage, we have very complex scenario of migrations... Nevertheless, imagine all life forms sequencing of whole genomes is available," he said.

India is a cradle of languages

Syed Akbar
Hyderabad, May 9: India has long been known as the sojourn of early human
migration from Africa and latest research studies by city scientists based on
male sex chromosome shows that the country also served as the cradle of
languages.
The forefathers of Austro-Asiatic linguistic family originated in India and
later dispersed themselves to different places, according to a joint study by
the Hyderabad-based Centre for Cellular and Molecular Biology and
Molecular anthropology group of Biological Anthropology Unit of Indian
Statistical Institute and the Shillong-based North Eastern Hill University's
Department of Anthropology.
The Austro-Asiatic linguistic family is considered to be the oldest
in the country and people who speak these languages are scattered all over
Southeast Asia. The scientists' team analysed the male Y-chromosome
to trace the origin and historic expansion of Austro-Asiatic groups of India.
The report was published online in the latest issue of science journal of
international repute BMC Genetics. The city team studied genetic data of
1222 individuals from 25 Indian populations, covering all the three branches
of Austro-Asiatic tribes, Mundari, Khasi-Khmuic and Mon-Khmer. The
team, comprising among others Dr Lalji Singh, K Thangaraj and BM Reddy,
compared the data with the already available scientific information on 214
relevant populations from Asia and Oceania.
The results suggested a strong paternal genetic link, not only among the
subgroups of Indian Austro-Asiatic populations but also with those of
Southeast Asia. However, maternal link based on mitochondrial DNA is not
evident.
The haplogroup in the Austro-Asiatic populations had originated around
65,000 years ago and the ancestors of this linguistic family carried it
further
to Southeast Asia via the Northeast Indian corridor. "Subsequently, in the
process of expansion, the Mon-Khmer populations from Southeast Asia seem
to have migrated and colonised Andaman and Nicobar Islands at a much later
point of time," the study pointed out.
The present findings are consistent with the linguistic evidence, which
suggests that the linguistic ancestors of the Austro-Asiatic populations have
originated in India and then migrated to Southeast Asia. Four major
linguistic
groups, Austro-Asiatic, Dravidian, Indo-European and Tibeto-Burman, are
present in the Indian sub-continent and the ancestors of speakers of these
languages might have entered at different points of time.
The Austro-Asiatic languages include Mundari, spoken by a number of tribes
living in Chota-Nagpur plateau in Central and Eastern India, Mon-Khmer
(Nicobarese and Shompen tribes from Andaman and Nicobar islands) and
Khasi-Khmuic (Khasi subtribes from Northeast India).
The team sampled almost all the Austro-Asiatic populations of India covering
the entire geographic and micro-linguistic heterogeneity inherent among
them, including the molecular genetic data on the Austro-Asiatic Khasi from
Northeast India, considered as an important corridor for human
migrations to Southeast Asia.
"Austro-Asiatic populations of India are not only linguistically linked to
Southeast Asian populations but also genetically associated. It is most
likely
that these populations have come from Central Asia through the Western
Indian corridor and subsequently colonised Southeast Asia, although more
data on Y-chromosome and mtDNA are needed from other relevant
populations to draw firmer conclusions," the study pointed out.