Who we are and where do we come from
by Sujatha Byravan, ‘TheHindu,’ Chennai, January 19, 2019
A compelling story of new DNA findings, tracing the people of India from prehistory to near history
By interpreting the palimpsest of the human genome, population geneticists have made rapid progress recently and traced the migration of early humans out of Africa and into distant lands across the earth. Corroborations from anthropologists and philologists, who have independently written some parts of this story, now make it possible to make more definite claims regarding the waves of homo sapiens that migrated out of Africa (OoA). The first OoA migrants emerged around 70,000 years ago. About 5,000 years later their descendants reached India and faced archaic humans living here already. Waves of these OoA migrants also reached parts of central Asia and Europe between 60,000 and 40,000 years ago. Early Indians came to India over time from Africa, West, East and Central Asia. Homo sapiens or ‘wise man’ has been around for about 300,000 years but humans still carry traces of Neanderthal DNA in their genes.
Who were our forefathers?
Geneticists have for a long time been using the DNA in the nucleus of cells to identify specific shared DNA sequences, or haplotypes and haplogroups — when these are shared in sub-populations. These shared sequences can be traced and also compared with DNA from other individuals either living or dead in different geographical areas. This is how many African Americans try to identify the places in Africa and elsewhere from where their forefathers came. But, more recently population geneticists have also been using DNA from mitochondria — intracellular powerhouses that have their own DNA and can be traced in the maternal line.
The DNA in the Y chromosome can similarly be used to trace sequences inherited from the father or the male lineage, since the Y chromosome is present only in men. These approaches have yielded a wealth of results since it is mostly men who migrated from one place to another and passed on their Y-chromosome to their sons when they mated with local women. DNA from skeletal remains is revealing new stories about our past, our relationships and our cultures.
Joseph writes a compelling story about these findings and traces the people of India from prehistory to near history. It is an astonishing tale, difficult to put down, but dense given the amount of detail it covers. Following a short chronology of the modern humans in Indian Prehistory, the book has four chapters along with an introduction and epilogue. These narratives of population genetics, deftly interwoven with archaeological research and philology, are about the following: the first Indians, the first farmers, the first urbanites or the Harappans, and the last migrants or the Aryans.
Out of Africa
Each chapter presents many interesting storylines. For example: Although from the same single OoA migration, our ancestors likely reached different areas of the Indian subcontinent at different times.
The earliest Palaeolithic tools in India are from Attirampakkam in Tamil Nadu dated to around 1.2 million years ago. But the earliest microliths, small stone tools used by modern man, dated to 45,000 years ago, were found in Mehtakheri in the Nimar region in Madhya Pradesh. It was possible to trace the spread of humans through central and eastern India from around 45,000 to 35,000 years ago, by following the mitochondrial haplogroup M.
Towards the end of this spread, the world was entering full glacial conditions, but new microlithic innovations most probably helped modern humans to hunt, increase their numbers, and overcome the adverse climate and archaic humans who had already been in the subcontinent for hundreds of thousands of years.
Another example: There is evidence of early agriculture, probably by the first Indians, in the Mehrgarh, Balochistan region from around 7000 BCE.
Evidence for migration of agriculturists from the Zagros region of Iran into this area is available and one can see signs of their genetic markings in the Indian population even today.
The Harappan civilisation was like none other in a large number of ways and covered close to a million square kilometres. With very precise town planning, public infrastructure, storm water drains and sanitation, it had the region’s first urbanites who were also trading with people of central Asia. With changing climate and deteriorating conditions, Harappans moved out, some of them southwards, where they interacted with people in South India and formed the Ancestral South Indians. Just as the Harappan civilisation was beginning to collapse, there was an influx of people from the east into India.
Significantly, by about 2000 BCE, critical aspects of India’s population were already in place. Combining evidence from Y-chromosome haplogroups from the Steppes of Kazakhstan, conducting genome wide analyses and correlating these with archaeological discoveries indicates that between 2000 and 1000 BCE, multiple waves of migration from the Steppe pastoralists brought new European languages, cultural and religious practices that changed the people of South Asia forever.
This book is excellent science journalism, the kind that we need more of in other disciplines. Following the DNA sleuths and their stories is hardly a simple task. Ideologues of racial superiority may likely not agree with these or other scientific findings about evolution or human migrations.
But since it is impossible to disprove non-science, there is no point in wasting one’s energies to do this. Instead, now that we have an understanding of our histories, perhaps what Indians needs to focus on is where they and their country are headed.
Early Indians; Tony Joseph, Juggernaut, ₹699.