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)
Genes - The Storehouse of all our Information; the Heritage of our Ancestors; the Inheritance of our Future generations.
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.
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...
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.
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?
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!!
Thus, 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
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!!
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
Hence, 6 major laboratories with the help of Government of India, formed the Indian Genome Variation Consortium in order to undertake this Himalayan endeavor. IGVC preliminary results have revealed, that though India is a conglomerate of diverse ethnic lineages, they can still be clustered into broader groups of genetic homogeneity.
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.
Over the eons, Dravidian lineages have mixed with Indo-Europeans, Austro-Asiatics have mingled with Dravidians, and bridge populations in central India are blends of Dravidian, Indo-European and Tibeto-Burman groups. In fact, the tribal populations of our nation represent some of the genetically oldest surviving populations in the world..
Indian Diversity from North-East-West-South
The tribal populations of India
There have been numerous OTHER studies conducted on the same lines as well and let me share with you some examples:
Macrohaplogroup M, a cluster of Proto-Asian maternal lineages, represents more than 60% of Indian MtDNA. Now, observe the similarities for this Haplogroup found 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)
The analysis presents startling findings like the similarities between Kashmiri and Tamil populations!! More details can be obtained from the following link {Genetics_and_archaeogenetics_of_South_Asia}.
Same same yet different :)
(Image courtesy Imagesbazaar.com)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 had large number of pigment producing cells called Melanocytes and thus had 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 produces Vitamin D 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
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. 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. 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 two-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 We, INDIANS are Genetically, the OLDEST human inhabitants of this planet outside of Africa. All non-African populations have Descended from Us and not only 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, plzz know your roots before promoting political differences between the people of this nation. Even if the Aryans came from outside India, their arrival would just be a second HOMECOMING and not an INVASION by an alien race!
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:
.PNG){kind=link}
No comments:
Post a Comment