The contribution of recent genetic research to the reconstruction of Indian past and identity

A new genetic study, made by scientists based in India and the United States, has revealed that the Indian population descends from two main components: Ancestral South Indians, arrived in the subcontinent around 65000 years ago, and Ancestral North Indians, arrived around 45000 years ago. The northern component is akin to Central Asian, Middle Eastern and European populations, whereas the southern one appears originally very different from Ancestral North Indians ("is as distinct from ancestral north Indians and East Asians as they are from each other"), even if during the millennia it has widely mingled with their descendants, creating the present Indians.

The presumed Aryan invasion of the II millennium B.C. is eclipsed by these data, and the origin of castes is identified in endogamous usages emerged from local tribes, and not from foreign invasions:

Another finding is that the castes and tribes in the country are not systematically different. "(The study) supports the view that castes grew directly out of tribal-like organisations during the formation of Indian society," said Kumarasamy Thangaraj, another CCMB scientist. Singh said the castes grew directly out of tribal set-ups during the formation of Indian society.

Some historians had argued that caste in modern India was an invention of colonialism in the sense that it became more rigid under colonial rule, but the "results indicate that many current distinctions among groups are ancient and that strong endogamy (matrimony within one's own isolated group) must have shaped marriage patterns in India for thousands of years".

(http://www.dnaindia.com/scitech/report_indians-are-one-people-descended-from-two-tribes_1292864)

In an article on the Times of India (http://timesofindia.indiatimes.com/city/varanasi/Indian-scientist-set-to-change-world-history/articleshow/5301655.cms) we find some other interesting assertions made by Prof. Singh in a conference in Varanasi at the beginning of December:

Saying that Indian population was made up of many populations that have varied genetic compositions, he also added recent studies on DNA linkage indicated an invisible thread (trait) that bounded the Indian population comprising populations of other countries in the sub-continent including Pakistan, Sri Lanka and Malaysia, believed to have originated almost 33,000 years ago.

"The study is on to trace the ancestors of Ancestor North Indian (ANI) population, while the ancestors of Ancestor South Indian (ASI) population has been already traced," he said. "Ongee and Jarva species have been established to be the ancestors of ASI population while DNA matching has found resemblance of East African population with Kurumbha species in Kerala and Raghuvanshi of West Bengal," he added.

"We are looking for DNA from Afghanistan, Pakistan and Jammu and Kashmir to trace the origin of ANI population and once that is established, we would be in a position to indicate the movement of ANI population towards European countries that would change the face of world history," he said.

Here you can read another popular article about the same research:
http://timesofindia.indiatimes.com/news/india/Aryan-Dravidian-divide-a-myth-Study/articleshow/5053274.cms

Here is the page of the scientific article with the abstract:

http://www.nature.com/nature/journal/v461/n7263/full/nature08365.html

And here you can find freely available supplementary information:

http://www.nature.com/nature/journal/v461/n7263/extref/nature08365-s1.pdf

Another recent study, by Sharma et al., published exactly one year ago on the Journal of Human Genetics (http://www.nature.com/jhg/journal/v54/n1/abs/jhg20082a.html), is also concerned with the origin of castes and particularly of Brahmins. It says:

"The observation of R1a* in high frequency for the first time in the literature, as well as analyses using different phylogenetic methods, resolved the controversy of the origin of R1a1*, supporting its origin in the Indian subcontinent. Simultaneously, the presence of R1a1* in very high frequency in Brahmins, irrespective of linguistic and geographic affiliations, suggested it as the founder haplogroup for the population. The co-presence of this haplogroup in many of the tribal populations of India, its existence in high frequency in Saharia (present study) and Chenchu tribes, the high frequency of R1a* in Kashmiri Pandits (KPs—Brahmins) as well as Saharia (tribe) and associated phylogenetic ages supported the autochthonous origin and tribal links of Indian Brahmins, confronting the concepts of recent Central Asian introduction and rank-related Eurasian contribution of the Indian caste system."

That means that the traditional theory of the external origin of Indo-Aryans with their priests, the Brahmins, holders of the sacred Vedic language, is not supported by the genetic research. The haplogroup R1a1 (R1a1a in Underhill's classification, see http://en.wikipedia.org/wiki/R1a1#cite_ref-6), characterized by the mutation M17, has been associated to the Indo-Europeans, and an outdated theory placed its origin in Ukraine, that is in the Kurgan area, apparently supporting Gimbutas' theory. But in India not only we find this haplogroup exceptionally frequent in Brahmins (72.22 % in West Bengal Brahmins), but also quite frequent in tribals like Saharia (Munda speakers, 28.07%) and Chenchu (Dravidian speakers, 26.82%). The highest known variance of R1a1* among Kashmiri Pandits (0.52), is a sign that in this population it is older than in the other ones object of study.

In this image you can see the frequency of R1a1a (old R1a1) according to Underhill et al., showing the high concentration of this haplogroup in South Asia and in Eastern Europe, which appears as a second source of diffusion of this haplogroup, and possibly of the related Indo-European languages.
http://www.nature.com/ejhg/journal/vaop/ncurrent/abs/ejhg2009194a.html

Here is the map (from the cited Sharma's study) of the diversity within the R1a1* haplogroup, clearly showing the maximum in Kashmir and Northern India, thus suggesting the origin of the haplogroup from this area. Here is possible to compare the data about the variance and connected age of the haplogroup in different populations:
http://www.nature.com/jhg/journal/v54/n1/fig_tab/jhg20082t3.html#figure-title