DNA study on ancient skeletal remains and contemporary Indian Populations
The Anthropological Survey of India has a rich repository of series of ancient human skeletal remains representing a wide range of cultural phases from late Stone Age through prehistoric periods to early historic period. A number of scientific reports have already been published on their biometric and morphological attributes. These research results are required to be re-examined in the light of modern methods and techniques, presently available especially in DNA fingerprints.
Recent advances of DNA technology, particularly the Polymerase Chain Reaction (PCR) techniques have provided us a unique opportunity to study the ancient skeletal materials. This promises to resolve various issues relating to their origin, distribution and their place in evolutionary history.
During the Tenth five Year Plan period, it was proposed to restudy the series of skeletal materials housed in the Survey with the help of newly acquired technique of D.N.A. fingerprints so as to throw further light on the migration, admixture and affinities of the ancient people. It is also proposed to extend this study to cover the contemporary populations as well to examine the nature and extent of genetic variation of ancient populations and their contribution to the present day populations. These studies would have a paramount significance and importance to unveil the course, direction and magnitude of human evolution.
Analysis of Roopkund skeletal material: Survey was the first to initiate Roopkund Expedition in 1946. The DNA from the skeletal material collected is now analysed by Survey's scholars in CCMB, Hyderabad. This helps in resolving the mystery of human tragedy of a great historical importance. Besides, the technology once standardized would be of immense help for the study of more ancient molecules.
Analysis of DNA from the contemporary populations belonging to Primitive Tribes in the main land and the Jarawa of Andaman and Nicobar Islands has revealed genomic foot prints in the Indian subcontinent dating back to first out of Africa migration i.e. 70,000 years before the present.
Publication of the results of the study is a first step for survey to make a mark in genome diversity studies, in terms of establishing DNA technology and plan for the future studies that have far reaching implications to focus on genome diversity and implications of health.
Most Significant Findings
In our Indian mtDNA genome screening, Pauri Bhuiya tribe of Indian main land population which distributed in the state of Orissa shares genetic similarity with the hitherto Andaman Islanders, the Jarawa, the Onge and the Great Andamanese by sharing 7 mutations of Andaman Islands characteristic haplogroup M31.
We redefined M31 haplogroup by 4 coding mutations, at np 15440, 15530, 1176 and 4907. These four mutations were also shared by Rajbanshi of West Bengal, India (Palanichamy et al 2006). Pauri Bhuiya, Jarawa and other Great Andamanese share M31a characterized by polymorphisms at np12876, 3999. M31a branched into M31a1, characterized by Andaman Islanders and M31a2, characteristic of the Pauri Bhuiya.
Our results shows haplogroup M31 evolved on Indian mainland and later populated Andaman Islands during Upper Paleolithic times.
Genetic links with North Eastern Indian coastal populations like Rajbanshi and Pauri Bhuiya convicts genetic evidence for “Southern route” hypothesis.
Contributions to Human Origin and peopling of India
Anatomically modern humans evolved out of a pre-existing species in the Late Pleistocene period some where in Africa. DNA studies being conducted in the contemporary human populations across the world indicate that all of them are related to each other, who in turn find relation with the living great apes like Chimpanzee. In deed, it is a common knowledge today that about 98% of the genome in every one of us is similar to the one among the Chimpanzees. It is plausible that a common ancestor of the Chimpanzee and human might have been swinging about the trees, about 5 million years before. Scientists study ancient bones and fossils to investigate human origins and evolution. Comparative anatomy of skeletal material from fossils and ancient as well as modern skeletons of the humans across the world allow us to think that there has been a smooth transformation from Homo erectus to modern humans, suggesting that modern humans gradually evolved from ancient humans, at least in Asia. But remains of modern looking humans found in South Africa date back to about 100000 years suggest a recent African birth place for Homo sapiens. Rich Paleolithic signatures are found in many parts of the country, represented by the stone tool sites.
In 1977, biologists in Svante Paabo, Germany and Mark Stone King in the USA extracted Mitochondrial DNA of the arm bone of a Neander valley skeleton, which conclusively proved that the Neanderthals were not our ancestors but are from a different branch of the human evolutionary tree and their common ancestor might have lived around six lakh years before.
Scientists estimate that 2 to 4% minute changes (mutations) accumulate in the DNA of animals in about one million years and by measuring the number of mutations between peoples from different parts of the world, one can calculate the time of their separation. This DNA clock also tells us that the last common ancestor between the Chimpanzees and humans lived about 350000 generations before, that is about 5 million years ago(Lucy might have been our ancestor, who lived between 3 -5 million years before).
DNA sequencing has enabled us to study the mutations in functional as well as other parts of the genome to understand the affinity and phylogeny of different peoples. The mt DNA and Y chromosome are passed on in the maternal and paternal lineages, respectively to the succeeding generations and the mutations on the DNA of mt DNA and Y chromosome reveal lineages along the continental lines.
Anthropological Survey of India’s on going project ‘DNA Polymorphism of the Contemporary Human Populations and Ancient skeletal Remains’ thus far could cover over 45 ‘Primitive’ tribal populations (3283 samples), including three populations from the Andaman archipelago. Using whole genome sequencing combined with multiplexed SNP typing, this study investigated the deep structure of mt DNA haplogroups in Indian populations.