Indian Instincts

named Sasha, meaning ‘little boy’ in Russian. My father often travelled to Egypt and Muscat as well—for aircraft fuel—and he would come back with photographs and stories from those lands. Our home was full of the memorabilia he picked up from abroad; he even added significantly to my book collection. Through the gift of knowledge that my father gave me, I realized India was just a microcosm of the world, populated by many different types of people. The scope of my curiosity expanded from India to the diversity of the people of the world.

As I grew up, my curiosity gradually made me look for answers in the scientific discoveries of the time. I found in Agassiz’s research, for example, that between 70,000 and 50,000 years ago, Earth was frozen. The ice caps were expanding as a result of a worldwide catastrophe that had occurred because of a monumental change in climate. Cold deserts in Africa expanded, sea levels everywhere dropped, prey became rare in the drought, and hunters desperately searched for food. But humanity, on the verge of extinction, was miraculously saved by a massive leap of development in the human intellect. In order to survive, a small group of humans living in the severely cold and parched Africa 50,000 years ago were able to think the unthinkable—they had the idea of leaving Africa forever. It was assumed that these earliest humans probably did so on foot, walking over frozen lands along the coast. It was the primordial survival instinct of humans in the Ice Age that kept our species alive.

For a long time, scientists tried hard to find proof of this journey, but archaeologists were unable to unearth any evidence of the route taken by the first humans out of Africa.

The answer was found in our own DNA by genetic scientists. Studies showed that the first modern humans left Africa in two distinct evolutionary migrations. The first wave apparently walked eastward along the coastline to reach Australia. The second wave was more successful—they moved northward to populate the Middle East, Asia, Europe and the Americas. As each group of people broke away to found a new community, like branches of a tree, it took along a sample of the parent population’s genetic blueprint.⁹

So when did the first human from Africa reach India? And if we do indeed share one origin that lies in Africa, how did we end up looking and sounding so different from each other? What about all the communities in India? Is there any scientific basis for their different characteristics?

These were the questions that led me to talk to population geneticist Professor Ramasamy Pitchappan a few years ago. It had been a few months since I returned to India after fourteen years of living across the world, and I soon picked up my personal inquiry into the origins of India’s diversity that had intrigued me as a child. I had read online about the Genographic Project, a formidable ten-year global collaborative study started in 2005 that had conducted an advanced DNA analysis of various indigenous communities around the world to find our origins. I tried to contribute to the global project by purchasing their gene kit online. It would be shipped to me in India, and I would use it to contribute a sample of the skin of my inner cheek and send it back so that my DNA and ancestry could be analysed. However, I was informed that it was forbidden to send genetic information and related material out of India. I was disappointed, but not disheartened, and continued to pursue my quest. Within days, I found that the Genographic Project had an India director—seventy-year-old Professor Pitchappan—who had researched more than 12,000 blood samples from ninety-one tribes and 129 castes in India for their genetic compositions.¹⁰ I was excited beyond words.

I got in touch with the professor, first through email and then phone calls. He was friendly and gave me his time, patiently explaining how DNA is a manual of life itself. It is in our blood and all other cells, coordinating our life processes, strung together in pairs of forty-six chromosomes in an incredibly long sequence. If laid out, the DNA of a person can stretch from Earth to Moon and back 3000 times.

‘Because of its length, when it is inherited, DNA is prone to developing certain glitches in its sequence similar to “copying errors”,’ he explained to me on the phone. ‘These copying errors are called mutations—we all have them.’

‘Copying errors?’ I asked.

‘You heard right—copying errors!’ he confirmed.

He explained that this is how with each new generation the chromosomes get chopped up and reordered, making each baby a unique combination of its parents.

‘Each generation inherits the X and Y chromosomes from the mother and the father respectively, right?’ I asked.

‘Correct. But the Y chromosome, in fact, does not get reordered in every generation,’ he said. ‘And so the Y chromosome is the key to our history, since it passes unchanged from father to son. If, once in an evolutionary blue moon, a genetic mutation does occur, that mutation too gets passed on in the Y chromosome to the next generation.’

‘Okay, so in this way, every male progeny collects the genetic mutations of his ancestors?’

‘Yes, the collection of these mutations in our DNA writes our ancestral history.’

The professor’s research was done in his laboratory at Madurai Kamaraj University in Tamil Nadu, the southernmost state of India. I had learnt from what I had read about the Genographic Project that at this laboratory he painstakingly distilled blood samples to extract DNA, from which he traced Y chromosome mutations to find the ancestral trail to several communities and tribes in India.

In one of our conversations, he told me how one morning twenty years ago he heard from an old friend, fellow geneticist Spencer Wells from the University of Austin in Texas. Wells told him that he was looking for the route that the first human migrants had taken when they left Africa in the Ice Age