A study published recently in 2018 in reputed Scientific Journal “Nature Scientific Reports” by the Human Genetics Research Group of Shri Mata Vaishno Devi University provided strong evidences based on Genetics refuting the much acclaimed “Aryan Invasion Theory”. The study has been supported by a grant to Dr.Swarkar Sharma, coordinator Human Genetics Research Group by National Geographic Society USA. The paper is receiving great appreciation worldwide and has been creating a buzz in social media.
As evidences exist that ancestors of the human population of the world, originated in Africa and these ancestors migrated out of Africa and populated the world; India has served as a major corridor for modern humanmigration and was amongst the first regions of the world populated by humans once they left Africa. Jammu and Kashmir is the northern most state of the Indian sub-continent. It is a land with extensive human diversity which has witnessed many prehistoric and historic migrations and invasions across the ages due to its geographical location and natural bounty. The migrations and invasions have resulted in the high cultural and social diversity of the region. The most interesting of all and highly debated has been”Aryan Invasion Theory” which has been often associated with Caste formation in the Nation.The basic belief and evidences of invasions world-wide, have been mostly found associated with male migrations and contribution to the genetic content of a population.As most of the previous studies from India, Eurasia or studies specifically addressing this question in the past almost completely lacked sampling from the region of Jammu and Kashmir. Most of these studies, concluded that our maternal lineages were relatively very few(meaning only of those ancestors that migrated to the region during early ice age times (before 20-30,000 years ago) and since then majorly males migrated, be it associated with invasions or other migrations. Thus, despite various evidences it kept the “Aryan Invasion Hypothesis”alive.
Dr.Swarkar Sharma coordinated the study and team comprised of research scholars,”Indu Sharma and Varun Sharma from SMVDU”; “Akbar Khan” from Jammu University; Faculty from both Institutions “Dr.EktaRai and Dr.Parvinder Kumar”; “Prof. RNK Bamezai”, a well-known human Geneticist in India and “Dr. Miguel Vilar”, coordinator Genographic Project of National Geographic Society USA. The team wanted to study specifically if maternal lineages in India are as conserved as claimed in literature or evidences exist contrary to what is believed? They picked mitochondrial DNA, which only is inherited from mothers to children, means only females inherit mitochondrial DNA. If a variation (change) in this type of DNA occurs it is to be inherited to children and further females inherit it to next generation and it continues. So based on mutations shared by different individuals one can find how one is related to each other as well as find lineages. The team looked for mitochondrial DNA variations using Next Generation Sequencing Technologies and found it is not only few (already known and which are shared by other Indian population also as reported) but has lot new (potentially more than 19, found in the present study), indicating many new lineages exist (never reported earlier before). It justifiesthat Indian maternal lineages are not restricted to only few. The various type of high end analyses also indicated that ancestral maternal migrations not only happened prior to 20-30000 years before present but later too. To simplify the understanding, as these variations occur at a rate one can estimate the age of the event based on that. Though such calculations are complex but for an idea:if one variation occurs in approx. 1000 years, and 10 variations are seen when two individual DNAs are compared,indicate their ancestors were separated 10,000 years ago.
This study highlights, most of the migrations that contributed to genetic composition of Indian populations was not the males exclusively but migrations of the both genders and much before the anticipated time of origin of caste system in India. The most recent such contributory migrations, probably had happened prior to 8-10,000 years before present. There may have been some contributions associated with language dispersal from other regions to India or may be with Agricultural expansion (cultural exchange and by preference selectively may be, for Indo-European language family), which needs to be critically evaluated further. This one can correlate with English in present times, almost whole world usesEnglishas main language of communication, does not mean have extensive British genetic component also), A language is a medium of communication and can be learnt without the genetic exchange and same is the case with learning of agricultural techniques. So the crux is no major invasion or migration occurred that was of males exclusively and shaped population of present India. We have had major migrations of human populations deep in time, both Males and females (before 8,000-10,000) and caste system originated in India as social structure later, but became very complicated in course of time.
Interesting is; as per Dr. Sharma, this is a preliminary study of only 83 samples and it has given such high diversity. If we increase the sample size and extend the study (presently working on it) a lot more will be unravelled.