What DNA Testing Reveals About India’s Caste System

  • Share
  • Read Later
Dr. Kumarasamy Thangaraj

Kumarasamy Thangaraj takes a blood sample from an Andaman islander, as part of his research into the genetics of India's castes

Kumarasamy Thangaraj traveled 840 miles (1,350 km) off of the eastern coast of India by plane, then ship, then six hours by car, then ship again to collect blood samples from an isolated tribe of hunter-gatherers on the Andaman Islands. Their blood, he explained through an interpreter, would help him understand a pivotal moment in India’s genetic history. The tribesmen had never heard of a gene before or an academic study for that matter, and the whole pitch struck them as an interesting diversion from their usual routine of spearfishing.

“They mostly laughed,” Thangaraj says, before they offered up their arms in exchange for food. A few needle pricks later, they returned to their boats to fling short wooden spears into the water with uncanny aim, while Thangaraj made the long journey home to Hyderabad. He deposited the latest samples into a blood bank, alongside another 32,000 samples from his countrymen.

(MORE: The DNA Dilemma: A Test That Could Change Your Life)

The collective bloodlines at the Centre for Cellular & Molecular Biology, India’s leading genetic-research institute, pose a unique riddle for researchers. On the one hand, geneticists can trace nearly all bloodlines back to two ancestral groups, one hailing from Africa, the other from Eurasia. These groups mingled, married and swapped genes. A mixture of their genetic material can be found in nearly every person on the subcontinent today.

But at some mysterious point in history, these braided bloodlines began to fray. The population divided along linguistic, religious and tribal lines, to the point where it separated into 4,635 distinct genetic groups. Europe and Asia look positively homogeneous in comparison, says Thangaraj. He and his collaborators at Harvard Medical School wanted to know when exactly the Indian melting pot stopped melting.

(PHOTOS: The Future of Life — Celebrating the 50th Anniversary of the Discovery of DNA)

Their finding, recently published in the American Journal of Human Genetics, made waves when it was revealed that genetic mixing ended 1,900 years ago, around the same time the caste system was being codified in religious texts. The Manusmriti, which forbade intermarriage between castes, was written in the same period, give or take a century.

Thangaraj says the study shows only a correlation between the early caste system and the divergence of bloodlines, and whether one caused the other is a debate better left to historians. Nonetheless, it puts a stake in the ground, marking the moment when the belief that one should marry within one’s own group developed into an active practice.

(MORE: Capitalism Over Caste: The Success of India’s ‘Untouchable’ CEOs)

He also doesn’t want the early signs of a caste system to overshadow another finding of his study — how completely the population mixed 2,000 years ago. He points to the Paliyar tribe in the foothills of southern India. Their villages are inaccessible by car, and outsiders cannot visit them without a government permit. “They’re still in the forest,” says Thangaraj, “but still they have some affinities with other groups. At some point in time, everybody was mixed.”

It’s a point that he stresses to anyone who wants to turn bloodlines into battle lines. On Aug. 15, on India’s independence day, a mob from the Rajput community in Bihar attacked men, women and children in the Dalit community. They beat them with rods, killing one and injuring 54. “Look, we were all brothers and sisters 2,000 years back,” Thangaraj says of this sort of violence, “why are you fighting now?” Although he did observe one notable outlier from the extended family: the spear-wielding fishermen of the Andaman Islands have no trace of the genetic mix that pervades the mainland. Proof that the only the thing that really could have stopped India’s ancestral populations from mixing was an 840-mile schlep to a remote tropical island.

MORE: Off the Coast of India, in the Andaman Islands, Another Language Dies

SEE ALSO:  The Big Surprise of Martin Luther King’s Speech

184 comments
GokulGopan
GokulGopan

Caste system never existed as a part of some religious beliefs as its believed today! It was just categorization of people on basis of their choice for jobs! Like in today's world, all intellectuals be it scientists, engineers, analysts etc can be brahmins. Policy-makers, politicians, armed forces being Kshatriyas, business guys the Vaishyas and all odd job-takers be it janitors, sweepers,labour class belonging to Shudras! Any system around the universe, if not assessed regularly rots off to deformation! Every civilization had to face that!! Lucky for us Indians, that we had scriptural references which may be few tens of thousands years old, helping us to stand back on our feet on every stumble of such degradation!!!

evolbrain
evolbrain

Regarding the study on ethnicity, caste & gene flow in India, @AJHGNews informs me that pdf is free to all. Thanks!

indiantt
indiantt

research funded by Dravidians aka Africans of India

indiantt
indiantt

i dont have any shudra blood in me

Ocsicnarf
Ocsicnarf

Mixing is nice and good. Separation leads to political and health problems.

SanjayPachahara
SanjayPachahara

It is good to have more number of genetically different populations as it offers more chances of survival for human race. If genetic variation is lost because of interbreeding chances for survival of human race will be thinner as per Darwin's Theory of evolution.

DigamberBorgaonkar
DigamberBorgaonkar

The evolution of caste system evolved with social practices as is religion.

syrinje
syrinje

@sidin So, it's official? We can hold Manu responsible? A related article @pierrefitter shared earlier seems to indicate earlier inception.

absabbas
absabbas

@sidin Fair&Lovely got most benefit out of this i think!

nagiIPS
nagiIPS

@kris_sg I wonder what could have caused such swift change from melting pot to complete divergence.. could manusmriti be blamed completely !

bzxc
bzxc

India's caste system is so valid that Indian people can't break that system.

It's the modern India's barriar that blocks the nation going to democracy and prosperous one.

But India's high class still don't know the nagative effect of the caste system.



 

ppd27575
ppd27575

It is very interesting how a single word can change the dynamics of the discussion. Have always thought of this in terms of the word "caste". The moment the word "bloodline" was used in the article, the whole dimension changes and you sort of understand why people cling to the system so rigidly.

Eradicate the reason for the bloodline to exist and there is no reason for the entire system to exist.

However, it is easier said than done. More research needs to be done, and the information should be unquestionable or at the very least, accurate to a high degree.

In my opinion DNA mapping itself is pretty accurate and if the samples show that Indians have been inter-breeding in the past, then I accept it heartily as something positive. It is easier to accept that some decisions were made to retain the bloodlines and segregate the populace and that it was something that was deemed necessary at the time. It also follows that it should not be an issue to discontinue the same system once it's usefulness is over.

SakyaMohan
SakyaMohan

The caste is stupid politics. Sometimes back there was a research article finding significant correlation between bloodlines of Brhamans and Dalits. Does it really mean they are genetically one single group but culturally divided? This is a perpetual caste politics which preceded an anti-Buddhist war in the medieval Indian society. As Dr. Ambedkar says there is no any particular caste or race in Indian sub-continent that can claim any endogamous status. We have to end the brutality of caste monsters furthering the anti-social path by any means. May be search for bloodline should help to stop any more caste-based discrimination and violence on particular community which is basically claimed no caste in the history of caste-ridden India. I am dealing this issue in my forthcoming book "India: The Hell of Caste". 

Nand Kishor Manav
Nand Kishor Manav

We cant change others if we cant change ourselves. Face the truth with dignity that there is nothing great about a system based on Caste ! Caste system is destroying India and its an internal matter that we need to deal with, so there is nothing wrong with pointing it out as long as it is detrimental for our nation irrespective of the origin of media that is propagating this issue. I know they cant find anything based on molecular sciences as the root of caste came from the job of a respective person rather than something that traveled along the sperm ! However, the politician making it a point that they need to defy the science and no matter what one can't change her/his caste if not religion. A possible hypothesis therefore, could the caste be characterized using DNA and that is what the fools are trying.

benyaminshaker
benyaminshaker

Wow, No wonder indians are not all black these days

sperur
sperur

@leafwarbler I'm curious - which part(s) of the story did you find unconvincing?

NupuraMishra
NupuraMishra

In early 20th century, British scientists/Govt measured skull sizes to understand Indian Humanity and society.  The aryan dravidian theory was borne out of the contempt to understand a colony using skulls, and now genes. 

Race, Skull sizes, stones, genes couldn't describe culture , social behavior, religion or philosophy.  Since second world war, world is avoiding to explain culture using fundamental genes, races  or deviation from standard skull sizes.

Migration to India happened atleast 50000 years ago as per current evidence.http://phys.org/news/2013-06-refutes-early-humans-india-prior.html).What if there have been other modes of gene change, what if there are 5 fundamental genes ( if you can assume so) instead of two ? The study referred to has assumed two fundamental genes for study, and a timeline that is consistent with 19th century british understanding. 

Race/gene/Skull sizes should describe india society or history, 50 years after colonialism ended.



limmil
limmil

To be precise it is "Varna vyavastha" and not cast system.... This study says as if  "All the news papers are same because they all use recycled papers of each other".... It is the soul occupying the body which needs to be classified in "Varna Vyavastha" and not the body... Similarly the content of the news decides the level of news agency and not the paper used for it...  

Souls cannot be analysed using chemistry, hence if at all such studies can be done then... this study is taken up much ahead of its time... Another problem is people who don't even consider rebirth will never understand this journey of soul in many lives and moving upward in "varnas"....

Its high time when science should start spelling as to what science does not know rather than pretending to know everything and foolishly commenting on everything

karthigeyans
karthigeyans

Firstly, correlation does not prove causation. 1900 years +/-100 years, i take 1900+100 yrs, Christianity was born. can we then conclude its because of Christianity, there isn't any mix of people???  does manusmriti speaks about 4365 ethinicity not to mix?? 

PS49793974
PS49793974

@GokulGopan Rightly said. In fact, the western description of the 'caste' system of India is a gross simplification and misrepresentation. Jati and Varna are the two dimensions.

Jati representing the family bloodline along with the gotra rules for marriage (primarily to prevent marriage between similar bloodlines that causes genetic defects).


Varna was based on skill, knowledge and attitude towards work.

freemystics108
freemystics108

As the world sleeps, a yogi awakens, to What Is. Who knows when death takes, "get" this-that what is. ~_~ Here, now. :) 2 @aanchall

Shrutikay
Shrutikay

@indiantt : Obviously you know very little about science and logic. You are an african by origin, my friend. Just like all of us. And if you get racist with whom you so generously called shudra, believe me, you are only inviting being called a shudra by someone else like the White supremacists. Think before speaking. Open your mind,

limmil
limmil

@ppd27575To be precise it is "Varna vyavastha" and not cast system.... This study says as if  "All the news papers are same because they all use recycled papers of each other".... It is the soul occupying the body which needs to be classified in "Varna Vyavastha" and not the body... Similarly the content of the news decides the level of news agency and not the paper used for it...  

Souls cannot be analysed using chemistry, hence if at all such studies can be done then... this study is taken up much ahead of its time... Another problem is people who don't even consider rebirth will never understand this journey of soul in many lives and moving upward in "varnas"....

Its high time when science should start spelling as to what science does not know rather than pretending to know everything and foolishly commenting on everything

leafwarbler
leafwarbler

@sperur I need to read the paper before commenting more, but I'm skeptical of notion that castes were real barriers to gene flow.

Mikzy
Mikzy

@NupuraMishra We'll see about all that. This article seems somewhat incomplete, and I would like to see the data. And even if there are some genetic differences between the groups, the differences are most likely so minute as to NOT cause any fundamental changes to the behavior of the populations. I imagine politics, culture, influence etc. factor more into and divergence we see in the population's behavior. This is also one reason I hate studying the genetic "differences" between populations, politics factors in and people exploit these findings to their own ends, and use science to justify their views.

limmil
limmil

@viduur @waglenikhil @TIME @TIMEWorld @Swamy39 @skjain_05

To be precise it is "Varna vyavastha" and not cast system.... This study says as if  "All the news papers are same because they all use recycled papers of each other".... It is the soul occupying the body which needs to be classified in "Varna Vyavastha" and not the body... Similarly the content of the news decides the level of news agency and not the paper used for it...  

Souls cannot be analysed using chemistry, hence if at all such studies can be done then... this study is taken up much ahead of its time... Another problem is people who don't even consider rebirth will never understand this journey of soul in many lives and moving upward in "varnas"....

Its high time when science should start spelling as to what science does not know rather than pretending to know everything and foolishly commenting on everything

sperur
sperur

@leafwarbler thanks for the clarification. I'm just getting started on this myself.

sidin
sidin

@adabakm Oh great. Please do. Will save me time going to the library...

limmil
limmil

@AvijitSinha5 @viduur @skjain_05 @Swamy39 @TIME @TIMEWorld @waglenikhil 

Not only Varna Vyavastha but all deeper spiritual truths become incomprehensible during the Kaliyuga... Hence the saints of Kaliyuga prefer to play down such facts.... They even don't insist on concept of rebirth... hence even Jesus did not talk about rebirth... but now we r out of Kaliyuga... Slowly we will regain all the lost truths... And by the way chemistry cannot understand souls...

viduur
viduur

@skjain_05 @Swamy39 Agrawals opted for spiritual wisdom of Jainism also,therefore, I can c from my own experiences/study/realisations