Genetics of the Wandering Indian

We have 99 % same genes as any other Human,

And 96 % same as a Chimpanzee..

Howz that for Perspective ;o)

Since I started writing this blog, my endeavor has been to explore our rich ancient heritage utilizing as many different Scientific disciplines as I could. In the current post, I'm gonna use Genetics to help us understand the Genetic make-up of the various populations inhabiting India today and try to understand our origins.

Genes are the Storehouse of all our Information, the Heritage of our Ancestors and the Inheritance of our Future generations. There is no way that genetic studies can be questioned and the study of Genetics can perhaps be the only conclusive way to define the movement of human beings on this planet.

Even though I won't go deep into mythology this time, yet the inspiration of this topic has been a verse from the Kurma Puraan - In Bharatavarsha women and men display diverse colors, worship various gods and perform many different duties. The full length of their lives is said to be a hundred years, and live their lives according to virtue or vice.

Ancient literature mentions many different races inhabiting this planet and Archaeological sites such as Bhimbetka Rock Caves testify to the presence of Homo sapiens in India by at least 80,000 BCE - much before they were documented anywhere else in the world (besides Africa of course).

 

Bhimbetka Caves, Madhya Pradesh, India

But WHEN and HOW did Early Man reach India from Africa?

We learnt in a previous post (Evolution in Dashavtar) how modern Human-beings evolved from Primate ancestors. The currently accepted scientific belief is that this development took place in the African continent from where Homo-sapiens started spreading outwards.

This Out of Africa migration theory states that beginning around 100,000-70,000 years BP (Before Present), Modern Humans started spreading to different parts of the globe replacing the earlier local hominids like Nenderthal Man and Homo erectus.

The study of Genetic markers shows us that irrespective of Region/Religion/Color and Caste, Indians are the closest to Africans, more than ANY other population in the World! This genetic relatedness sugests that India was the FIRST stop for human beings coming out of Africa!!

For me the significance lies in this understanding that modern Humans coming out of Africa, spread to the rest of the World via India. It was from the sub-continent that waves of people migrated to other parts of Europe, Asia, Australia, and even the Americas. Indeed MODERN Human-being had reached India at least by 80,000 years BP; Europe by 40,000 years BP; and the Americas just about 14,500 years ago.

Out of Africa Migration

For those who have a background in Biology, I'm sharing a tidbit of technical information. Most Genetic studies involve tracing two types of DNA - the Y-chromosome or Y-DNA and the Mitochondrial or mtDNA. While, Y-DNA is passed solely from a father to his sons, the mtDNA is passed from a mother to all her offspring.
 

Y-DNA                                                mtDNA

Since mother's DNA is passed to ALL her children, it can be traced backwards by studying the chromosomal make-up of one's mothers' mother and so on right into the past until all lines converge on one person. Using this technique, Geneticists have actually been able to trace the First Maternal Ancestor of Mankind to Africa and call her the Mitochondrial Eve.
 

The Mother of Mankind traced to Africa

Scholars like Thangaraj et al.; Macauley et al have conducted series of studies on the Mt DNA of indigenous people of Malaysia and Andaman islands and these corroborate the notion that our African ancestors took a coastal route along the Indian Ocean around 65,000 BP to populate these regions.

According to Forster and Matsumura's assessment of the genetic evidence, ENTIRE continents of Asia, Europe, and the Americas were colonized by descendants of this initial group which perhaps included as little as four-five hundred women!

Coastal Route Out of Africa

According to a study conducted by Macauley et al in 2005, the entire landmass of Europe and Middle East was settled from an early offshoot of this migration that moved in once the Ice melted and climate in these regions improved. Another interesting study with a comprehensive analysis can be read here: {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC379225/}.

British Geneticist, Stephen Oppenheimer believes India to be the origin of all the Eurasian Eves and he claims that the ENTIRE populations of Central Asia, Middle East and Europe present today, have actually descended from four mtDNA lines that originated in the Indian sub-continent 50,000-100,000 years ago!!

This is not to say that human beings coming out of Africa only settled in India. Of course there were other populations coming out of Africa as well but presumably, we were the ONLY ones to survive and propagate throughout the WORLD. Another research regarding Haplogroup W also comes to the same conclusion as is evident from the image below:

Spread of Haplogroup W from Africa to India to the World

The reason for that is quite eloquently expressed by the famous sci-fi author Arthur C. Clarke in one of his bestsellers - In four great waves, with 200,000 years between their crests, the Ice Ages swept by, leaving their mark on the ENTIRE globe. Outside the tropics, cold glaciers slew those who had prematurely left their ancestral home; and everywhere they winnowed out the creatures who could not adapt.

Presumably, WE were the only ones who survived this 'winnowing' and were left with the responsibility to POPULATE the World!

DNA and Diversity

With this ancient DNA comes the ubiquitous DIVERSITY of our people.. Our scriptures record a plural society since time immemorial proving that we have always been a potpourri of different colors, cultures and appearances. However, such a situation also makes it really difficult to understand our Genetic relatedness.

 

Different Morphological Races of India

The races differ in appearance but NOT in genetic parameters. Our present diversity evolved as waves of  initial settlers moved both towards North as well as South of the country, all the time Intermixing and Migrating to OTHER countries.

One of the first studies linking India to Europe dates back to 1999 and was conducted by Estonian biologist Toomas Kivisild, with 14 co-authors from various nationalities. It relied on 550 samples of mtDNA and identified Haplogroup "U" as indicating a deep connection between Indian and Western-Eurasian populations. Now this may lead you to the infamous and now debunked Aryan-Invasion Theory but wait, there's more :)

The same haplogroup "U" was also found in the Lodha and Santhal tribes of Eastern India by Susanta Roychoudhury. According to Kivisild and his co-authors, the Indian and Western Eurasian haplogroup "U" varieties differ profoundly and their split has occurred as early as 50,000 years ago! In other words, yes there is genetic connection between India and Eurasia but a far more ancient one than what the Aryan Invasion presupposes!

Similar is the case with mtDNA Haplogroup "M" which occurs in about 60% of Indians irrespective of geographical location, 40% in Central Asia and even in American Indians but only 0.6% of Europeans exhibit the same. In fact, the tribal populations in India have higher frequencies of this haplogroup indicating that they are one of the oldest populations in the world!

Macrohaplogroup M, that represents more than 60% of Indian MtDNA shows following similarities in different populations of the country:

M2 - Most common in Bengal and Tamil Nadu (East and South)

M3 - Rajasthan and Karnataka (West and South-west)

M6 - Kashmir and Assam (North and East)

M18 - Rajasthan and Andhra Pradesh (West and South-central)

M25 - Punjab and Kerala!! (North and South)

The study has shown some Hindu caste groups to be genetically closer to Muslims in the same geographical region THAN to their own caste cousins elsewhere in India showing that our current RELIGIOUS differences are merely superficial and people in a specific region are more or less the same.

Genetically we all are the Same! 

 

(Image courtesy Imagesbazaar.com)

Similar findings have been observed in communities residing at diametrically opposite ends of the Nation-

R6 - Most common in Kashmir and Tamil Nadu (North and South)

R1a1 - Punjab and Bengal (North and East)

R2 - Bengal, U. P. and Andhra Pradesh (East, North-central and South-east)

U2a - Punjab and Karnataka (North and South-west)

U2b - Uttar Pradesh and Kerala (North-central and South)

U7 - Punjab and Gujarat (North and West)

More details can be obtained from the following link {Genetics_and_archaeogenetics_of_South_Asia}. Not just studies on Mitochondrial DNA but also the Y-chromosome studies done by Kivilid have revealed similar results. The Y-DNA Haplogroup "M17" or R1a1a regarded till recently as a marker of Aryan Invasion has been found in Dravidian tribes especially Chenchu who also happened to be closely related to the higher caste populations! The diversity in fact deminishes as we move into Central Asia thereby contradicting any supposed 'Male Aryan Invasion' of India especially since these have been present in the population since about 51,000 years ago!

The Genetic map, thus obtained, shows a remarkable amount of heterogeneity within different Indian groups while bringing out even more remarkable RELATEDNESS between groups till now considered to be at the opposite ends of the spectrum. The differences in our appearance are broadly a result of the ADAPTATION to local weather conditions over thousands of years.

Survival of the Fittest

Mankind first developed in Africa, therefore, the first modern humans would have had large number of pigment producing Melanocytes and darker skin. People living in the tropics, directly under the Sun, produce increased quantities of Melanin in their bodies to shield them from the harmful UV rays. Thus, their darker color is a PROTECTIVE mechanism of the body to prevent the incidence of Skin Cancer due to prolonged exposure to Sunlight.

Dark-skinned populations have greater protection against other health problems related to exposure to strong Solar Radiation, including the degradation of Vitamins such as Riboflavins, Carotenoids, Folic Acid etc. Melanin in the Eyes is also protective and people with Gray, Blue and Green eyes are in fact at a HIGHER risk of developing sun-related Ocular problems. 

Ultraviolet B radiation leads to the synthesis of Vitamin D in our skin but can also destroy Folate that is essential for babies growing in the womb. Dark skin protects from Folate destruction allowing normal reproduction and since the UV levels are high year round, there is still enough for the body to produce Vitamin D!

The Natural Selection Hypothesis suggests that lighter skin color evolved to optimize Vitamin D production in extreme northern and southern latitudes. Gradually, as we started moving out of Africa, some groups migrated and settled into cooler climates of Asia and Europe, and the selectivity for Melanin production decreased and mutations appeared, making the skin tone lighter. North or South of 46 degrees latitude, the dark-skin could not produce enough Vitamin D while light-skin could hence it thrived!

Indian skin color varies from Dark to Fair and everything inbetween

The Genetic variations of Mc1r and  SLC24A5 have been shown to be most common among pale-skinned populations. Similarly, tanning evolved so tht when UV - B radiation increases in early spring, the skin gradually darkens and keeps getting darker over the summer. During the winter, as UV radiation wanes, so does the tan allowing appropriate protection against folate destruction yet providing sufficient Vitamin D production.. S

Another example of such adaptation is the smaller extremities observed in the Mountain-dwelling races. This adaptation is summed up in Allen's Law of Genetics which states that the protruding parts of a warm-blooded animal's body (such as the tail, ears, and limbs), are SHORTER in animals of same species from colder regions. In other words, people living in COOLER areas have smaller bodies and flatter features to conserve the precious body heat compared to those living in WARMER climates. 

Over thousands of years, these traits became incorporated in our Genes and successive generations are now born with the same color and features as acquired by their parents. The same is quite evident in the populations dwelling in our Himalayan states.

Mountain dwellers show Allen's rule of Genetics

This doesn't make one race SUPERIOR to the other in any way except for the ability to SURVIVE in a particular environment! All our apparent differences are Nature's GIFTS to ensure survival in the respective climates we are born in and do NOT in any way make us different from each other from inside. The Racial and Ethnic discrimination prevalent in the world is based on such superficial issues that our future generations will laugh at us one day. The hatred being promoted world over today is as detrimental to Humanity as the Nuclear arms race was in the previous decade and the sooner we realize that, the better it is for us.

We are the World

The takeaway from this entire discussion seems to me to be three-pronged -

ONE, of course, is that all the different so called 'races' are extensions of the SAME Species and reflect nature's way to mold us into different shapes just as a potter creates different works of art on his wheel.

SECOND and more pertinent for this blog is that the genetic studies clearly refute Aryan Invasion Theory and indicate that whatever admixture of genes happened in the Indian sub-continent took place very close to the original migrations of Homo sapiens out of Africa.

THIRD and perhaps most startling for me is that we, INDIANS are genetically the OLDEST human inhabitants of this planet outside of Africa. All non-African populations have descended from ancient Indians and therefore not just culturally, even demographically India is the Cradle of Civilization for the Entire World!
 

Jai Ho India!

 

For those who still put faith in the old and outdated 'Aryan Invasion' theory and try to divide the country on racial basis, plz know your roots before promoting political differences between the people of this nation. I conclude this post sharing the poem Bharat-tirtha written by the Nobel Laureate, Gurudev Rabindranath Tagore which beautifully defines the Unity in Diversity of our ancient land:

Oh! Mother, Let me be blessed on the sacred shore of the Sea,

Where the World has gathered to pay reverence to Thee,

With outstretched hands we bow to Divinity,

With Supreme felicity Mother, We worship Thee..

No-one knows who invoked them all,

Who have gathered like currents of mighty rivers,

That dissolve themselves in the Divine Ocean,

Where Aryas-Dravids-Mongols-Pathans detach their Individuality.

Where our heart-strings play an endless tune of Omkar, 

In search of the Supreme, we've penanced for ages,

And oblated our Ego, in the Holy fire,

Throwing away differences, We emerge into Universality.

Come Aryas, Non-Aryas; Hindus and Muslims,

Come Englishmen; Come Christians and Buddhists,

Purify your hearts, Hold hands of the Out-castes.

For the Coronation of our Mother, by this sacred shore of the Sea. 

.

Aum Shanti: Shanti: Shanti:

.