Dr. P. Dayanandan
Image: Deepak Kumar
My story of migration begins in a part of the world we call the African Continent. My story is your story too. There was a time when not a single Modern Human like us (Homo sapiens) lived anywhere except in Africa. It is the birthplace of all humans, including those people who would deride it as a Dark Continent, colonize it, or enslave their own distant cousins in millions. Our species first appeared about 300,000 years ago during a period of warm climate in that land of beauty, biodiversity and plentiful food.
What lullabies my Mother sang?
About 200,000 years ago one African woman was singing lullabies to her children. She had no idea that her progeny alone would someday live in all continents of the globe. Only the children of that lullaby singing mother, popularly called the ‘African Eve’, survived to populate the earth. Some call her the ‘Mitochondrial Eve’. Other women either did not live to reproductive age or had no girl children. For, all the seven billion people who are living today and an estimated 140 billion who lived in the past, have inherited the mitochondria of ‘African Eve’, mother of all humans.
Mitochondrial DNA has unique marker mutations. The mitochondria are passed on only through mother’s eggs to the next generation. Mitochondrial DNA help us trace maternal ancestry. The history of our migration and the routes we took to settle throughout the world are coded in the DNA.
About the same time when ‘Eve’ was living, there was the ‘Y-chromosomal or African Adam’, father of all humans. Only males possess Y-chromosomes which are transmitted from fathers to sons. All males in the world carry the Y-chromosome of the ‘African Adam’. New DNA markers accumulated in the Y-chromosome over the past 200,000 years help us trace the migratory path of our male ancestors, and where they might have been when new markers appeared.
Out of Africa — Time to explore the world
Like the Neanderthals and other archaic species, our ancestors too left Africa. Was it curiosity to know what lay beyond the valleys, hills, and waters? Or the fluctuating climate during the Ice Age that made them move out looking for greener pastures, chasing the animals that they hunted for food? Earliest groups that entered Eurasia did not survive to spread further. It appears that about 60,000 to 70,000 years ago, a small group succeeded in entering Eurasia. One possible route of migration was via Egypt. The alternate southern route was entry into the Arabian Peninsula from Djibouti by crossing the strait of Bab-el-Mandeb, a narrow region that separates the Red Sea from the Indian Ocean.
A small percentage of Indian males bear witness to this early entry by the possession of a Y-chromosome DNA marker characteristic of this branch, the haplogroup ‘C-M130’. A haplogroup is a branch of population who share identical genetic markers either from a maternal or paternal ancestor. The earliest descendants of the ‘Mitochondrial Eve’, of a female haplogroup ‘M’, also entered South Asia at the same time. People with these ‘C’ and ‘M’ haplogroups represent the modern descendants of the earliest settlers, called as the ‘First People’ by author Tony Joseph. They settled on the land we call India about 60,000 years ago. Adivasis and a large proportion of South Indians are descendants of the First People. However, the First People also migrated and settled in many other regions of India. Subsequent waves of migrations tend to mask their identity.
I belong to this maternal haplogroup M that originated about 50,000 years ago either in Africa or southern Eurasia. About 60% of the Indian population belongs to haplogroup M, irrespective of their linguistic or caste groups. Naturally, my ancestral mother is also the mother of 60% of Indians.
Human diversity in India
Long before the development of DNA studies, ethnographers and physical anthropologists categorized Indians as: Negritos, often referring to South Indian tribes like Pulayans, Kadars and Irulars; Proto-Australoid with racial affinities to Australian Aborigines; Mongoloids; Palaeo-Mediterranean (=proto-Dravidian); and Armenoid European type. In many ways these early observations presaged our current understanding of Indian human diversity based on DNA genomic studies, including our connections to Australians and the revelation of admixture with Central Asians, Middle Easterners, Caucasians, and Europeans after the entry of Aryans about 3500–4000 years ago.
We are migrants par excellence
The Anthropological Survey of India initiated the ‘People of India’ project in 1985. It identified 4694 major communities with more than 50,000 endogamous castes. K. S. Singh who led this project declared that “An Indian is a migrant par excellence….there were waves of migration on a scale larger than probably anywhere else in the world, and that the mating patterns remained relatively flexible for a long time”.
Recent findings of whole genome and ancient DNA studies
During the past 15 years whole genomes of several living Indian groups were sequenced. In 2019 results were published in Science journal based on 523 ancient human remains, some of which were 8000 years old, from Central Asia and northern South Asia. The paper was co-authored by a team of 117 Indian and international scientists. Another investigation revealed information buried in the ancient DNA extracted from 4600 year-old skeletons of a man and woman from an IVC site in Rakhigarhi, Haryana. DNA studies of the male skeleton are yet to be published, but information was provided by two Indian scientists at a press conference. Both studies revealed that there was no Indo-Aryan ancestry. The male DNA had “more affinity with South Indian tribal populations” such as the Irulars. Since these studies made more definitive scientific statements on the absence of Indo-European language during the mature phase of the IVC, the discoveries have created controversies at various levels.
Enter the Zagros Iranians
Although many other ethnic groups including the Greeks, Persians Arabs, Mughals and the British entered India they did not contribute to any major genetic demographic changes in the population as the Aryans did. The only other major contribution came 10,000 years ago when the hunter-gatherers of Zagros mountains of Iran and the hunter-gatherers of South Asia (=First People of India) mixed. This is what the genome of Rakhigarhi woman and 11 others from the periphery of South Asia revealed.
What language did we speak?
What language did our First People speak 60,000 years ago? We don’t know! The People’s Linguistic Survey records that we now speak 780 languages. The current dominance of the Indo-Aryan language groups is deceptive. Most scholars, Indian and international, affirm that the language of the IVC people was Proto-Dravidian. Some who attempt to read the script on the seals also consider it Proto-Dravidian, but a fully satisfactory deciphering remains daunting. No Indo-European languages, such as Sanskrit, were present during 5500–2000 BCE of IVC. Even today, of the 26 Dravidian languages, 15 are spoken in the five southern states. The remaining are spoken by small groups in Maharashtra, Madhya Pradesh, Chhattisgarh, Orissa, Jharkhand, Bihar and Nepal. Brahui is spoken in Balochistan. Interestingly, the supercontinent that existed more than 600 million years ago in the southern hemisphere, was named by the geologist Eduard Suess after the forest-land of the Dravidian language (Gondi) speaking Gond people in central India. While no Dravidian language speakers are found in western states, Franklin Southworth in his Linguistic Archaeology of South Asia records the hundreds of Dravidian place names in Maharashtra and many names in Gujarat, Sindh, East and West Punjab, Haryana and western Uttar Pradesh. Thus Dravidian languages would have been widespread throughout India with open routes between Vaigai and IVC, until these western regions were dominated by Indo-Aryan dialects.
About 4000 years ago, when the Indo-Aryans were about to enter South Asia, there was also a migration from Southeast Asia of people speaking Austroasiatic languages, one of the four major language families of India. There are two branches of Austroasiatic linguistic family in India: Munda and Khasi. To complete this list, we can add migration of Tibeto-Burman language speakers of the Himalayan foothills, Manipur and Arunachal Pradesh. There was some admixture of their East Asian genome with people already living in these regions.
Enter the Indo-Aryan
Ancient DNA studies add evidence to the long-held view of scholars that Indo-Aryan language speakers entered South Asia during the declining phase of the IVC. Scientists now confirm that Aryan migration occurred between 2000 BCE and 1500 BCE. Proto-Indo-European language was first spoken by the people of Yamnaya culture (~3300 BCE) in a Steppe grassland region near present day Ukraine and Southern Russia. The Steppe pastoralists had wagons with wheels pulled by horses that gave them rapid mobility. About 3000 BCE they spread the Indo-European languages to Europe often replacing the original hunter-gatherer groups in Europe.
A southward migration through Central Asia introduced the Indo-Iranian and Indo-Aryan branches. Between 2000–1500 BCE the Indo-Aryan language (early Rig Vedic Sanskrit) entered the IVC. Today dialects of Indo-Aryan languages are spoken by a large number of Indians. This does not mean that these Indians are ethnically Aryans. Almost all are descendants of ancestors who were on this land 60,000 years ago; they would have spoken some pre-Aryan and proto-Dravidian languages even in the States that now speak Hindi. Dravidian languages, especially in the South, escaped this onslaught of Indo-Aryan, and continue to flourish. One of them, Tamil, thrives as a living classical language. The Indo-Aryan language speakers called themselves ‘Arya’, hence the common use of the term ‘Aryans’. As a people they had several Eurasian lineages. The Aryans were not a ‘race’ but an ethnic group, nomadic pastoralists with a unique culture and religious rituals at the time of entry. After entry into India there was extensive mixing with local people such that about 30% of South Asians derive their genetic ancestry from Aryans with a higher percentage of Aryan ancestry in the north. In north India “traditional custodians of liturgy in Sanskrit tend to have more Steppe ancestry.” Before 1000 BCE people in South India had no Aryan ancestry in their DNA. Now they do, due to the migrations of Aryan lineages to the south and some mixing.
The spread of Aryans was heavily sex-biased in favour of their males. The present-day genome of Indians reveal that the Aryans had social power and mated with local females, whereas the reverse did not happen or was minimal. Therefore, today most women carry the mitochondrial DNA branches of the First Indians while the Y-chromosomal branches of the First Indians diminished in numbers.
Creating the Caste system
The entry of Aryans not only made a major demographic change in the genome of India, but it also introduced a system of organizing the society that became synonymous with India. During or pre-Buddha times the varna system morphed into the caste system. After nearly 2000 years of admixture of population, this genetic exchange came to an end in the beginning of the 1st century AD. This happened due to the restrictions and ‘laws’ of Manu enforcing a strict hierarchical ordering of the society. Thus began endogamy and multiplication of castes. Those who commanded economic, political and liturgical power at the apex ensured the perpetuation of the caste system through the ruling class all over the land. This evil still lives with us.
My Father too was a Migrant
Like my mother, my father too was a migrant. Y-chromosome branches (haplogroups) appeared during the migration of the ‘African Father’s’ children after the group left Africa 65,000 years ago. I tested my DNA and found that I belong to a haplogroup named ‘H1’. This haplogroup emerged some 30,000 years ago. Since then the male line has been passing on this Y-chromosome for about 1200 generations to be a part of my cells.
About 2300 years ago when the Indian society was beginning to be compartmentalized into castes, a visionary Tamil poet, Kaniyan Poongundaran proclaimed his conviction that he belongs to every place and everyone on earth is his kin. No wonder that the first line of this often quoted poem is etched in a wall at the United Nations: “Yādhum Ūrē Yāvarum Kēlir”
(Dr. P. Dayanandan is a botanist who taught at Madras Christian College.)
