Hindustan Times carried a report a few days back on the recovery of DNA from Harappa age skeletons at Rakhigarhi village in Haryana.
What could ancient DNA tell us about the Holocene population composition of India?
Background:
Recent genetic studies of Indian populations shows that Indians are a admixture of two ancient populations, the Ancestral South Indians (ASI) and the Ancestral North Indians (ANI). The general understanding is that ASI has been resident in India since the Pleistocene, while ANI ancestry -which is related to Central and West Eurasians- was introduced in India at various times during the Holocene. ANI and ASI are deeply divergent populations having separated from each other as early as 30 thousand to 40 thousand years ago.
ANI ancestry in Indian populations decreases along a north to south cline and from upper caste to lower caste. Indo-European speakers have a larger component of ANI ancestry than Dravidian speakers with North Indian upper castes showing the highest ANI ancestry.
Scenarios:
Lets assume that a representative sample of Harappa society is eventually collected. What could Harappan DNA tell us?
1) There is an absence of ANI in Harappa DNA. Harappans are unmixed ASI. This would indicate that Harappans were not Vedic Aryans. It will also have implications on how farming was introduced to the Indus valley.
2) Harappans have some ANI ancestry i.e they are a mix of ANI and ASI . This would not automatically mean that the ANI ancestry was contributed by Vedic Aryans. ANI is likely a fairly diverse group i.e. different groups of ANI after separating from West Eurasians may have migrated into South Asia at different times in the Holocene. There is a possibility that ANI ancestry in Harappans reflects the migration of farmers (Dravidian speakers?) from West Eurasia in the earlier part of Holocene. Moorjani et al's study indicates waves of admixture of ANI and ASI, with middle and upper castes showing multiple layers of ANI ancestry and northern Indo European language groups shows younger admixtures dates than southern Dravidian speaking groups. These have been dated to a late and post Harappan period, although the authors say that their methods may have missed earlier admixture events. I am predicting that any ANI component in Harappans will be taken by many people as confirmation that the Vedic Aryans built the Harappan civilization.
3) Harappans have some ANI ancestry with markers suggestive of Indo-Aryan people ; One example could be the proposed West Eurasian origin -13910 C>T mutation for lactase persistence which in India shows a northwest to southeast declining pattern. This would favor the scenario that the Vedic Aryans were a part of the Harappan civilization. And there could be other markers typical to Indo-Aryans. Needless to say, such a finding will upset linguistic reconstructions of Indo-Aryan origins (proto-Sanskrit) thought to be not earlier than 2000 B.C.
4) Harappans are entirely ANI. This would mean that ANI co-existed alongside ASI in the Indian subcontinent but remained genetically distinct for thousands for years until admixture in late/post Harappan times.
5) Update: November 21 2015- [ Harappans are an ASI-Austro Asiatic mix, likely speaking a Munda related language. This is a wild card entry and I am basing it on a linguistic hypothesis that there are loans words indicative of a northwest India geography in the early parts of the Rig-Ved that have phonetic similarities to Munda languages. This language substrate has been termed "Para-Munda" as it occurs really on the western most fringe of the occurrence of Munda language distribution in India, and based on its linguistic properties seems to be an early branch of the Austro-Asiatic language family. This suggests that Indo-Aryans came in contact with resident Austro Asiatic language speakers in the Greater Punjab and Gangetic plains. Genetic work on Austro Asiatic language communities suggest a somewhat later entry (~ 2300 B.C) into East India from a Laos homeland, but Harappans just might represent an early wave of migrants from the east.]
We may get clear cut answers only when we can resolve with confidence the different layers of ANI ancestry.
I'm leaning towards Scenario (2).
What could ancient DNA tell us about the Holocene population composition of India?
Background:
Recent genetic studies of Indian populations shows that Indians are a admixture of two ancient populations, the Ancestral South Indians (ASI) and the Ancestral North Indians (ANI). The general understanding is that ASI has been resident in India since the Pleistocene, while ANI ancestry -which is related to Central and West Eurasians- was introduced in India at various times during the Holocene. ANI and ASI are deeply divergent populations having separated from each other as early as 30 thousand to 40 thousand years ago.
ANI ancestry in Indian populations decreases along a north to south cline and from upper caste to lower caste. Indo-European speakers have a larger component of ANI ancestry than Dravidian speakers with North Indian upper castes showing the highest ANI ancestry.
Scenarios:
Lets assume that a representative sample of Harappa society is eventually collected. What could Harappan DNA tell us?
1) There is an absence of ANI in Harappa DNA. Harappans are unmixed ASI. This would indicate that Harappans were not Vedic Aryans. It will also have implications on how farming was introduced to the Indus valley.
2) Harappans have some ANI ancestry i.e they are a mix of ANI and ASI . This would not automatically mean that the ANI ancestry was contributed by Vedic Aryans. ANI is likely a fairly diverse group i.e. different groups of ANI after separating from West Eurasians may have migrated into South Asia at different times in the Holocene. There is a possibility that ANI ancestry in Harappans reflects the migration of farmers (Dravidian speakers?) from West Eurasia in the earlier part of Holocene. Moorjani et al's study indicates waves of admixture of ANI and ASI, with middle and upper castes showing multiple layers of ANI ancestry and northern Indo European language groups shows younger admixtures dates than southern Dravidian speaking groups. These have been dated to a late and post Harappan period, although the authors say that their methods may have missed earlier admixture events. I am predicting that any ANI component in Harappans will be taken by many people as confirmation that the Vedic Aryans built the Harappan civilization.
3) Harappans have some ANI ancestry with markers suggestive of Indo-Aryan people ; One example could be the proposed West Eurasian origin -13910 C>T mutation for lactase persistence which in India shows a northwest to southeast declining pattern. This would favor the scenario that the Vedic Aryans were a part of the Harappan civilization. And there could be other markers typical to Indo-Aryans. Needless to say, such a finding will upset linguistic reconstructions of Indo-Aryan origins (proto-Sanskrit) thought to be not earlier than 2000 B.C.
4) Harappans are entirely ANI. This would mean that ANI co-existed alongside ASI in the Indian subcontinent but remained genetically distinct for thousands for years until admixture in late/post Harappan times.
5) Update: November 21 2015- [ Harappans are an ASI-Austro Asiatic mix, likely speaking a Munda related language. This is a wild card entry and I am basing it on a linguistic hypothesis that there are loans words indicative of a northwest India geography in the early parts of the Rig-Ved that have phonetic similarities to Munda languages. This language substrate has been termed "Para-Munda" as it occurs really on the western most fringe of the occurrence of Munda language distribution in India, and based on its linguistic properties seems to be an early branch of the Austro-Asiatic language family. This suggests that Indo-Aryans came in contact with resident Austro Asiatic language speakers in the Greater Punjab and Gangetic plains. Genetic work on Austro Asiatic language communities suggest a somewhat later entry (~ 2300 B.C) into East India from a Laos homeland, but Harappans just might represent an early wave of migrants from the east.]
We may get clear cut answers only when we can resolve with confidence the different layers of ANI ancestry.
I'm leaning towards Scenario (2).
If the people who built the towers at Gobekli-Tepe composed the Rg Veda as suggested by Dr Siddharth (link from Gaddeswaroops's blog) they could have built the Harappan cities easily. However, do the "many people" you mention really need evidence one way or another?
ReplyDeleteha ha... thanks for the link... according to "many people" this is entirely believable and as you say evidence one way or another won't matter..
ReplyDeleteI meant people in general about anything, be it location of ancient temples, nature of "vedic science", brahmastra, or plastic surgery. I was not maligning Dr Sidharth's evidence which I do not understand well enough to agree with or dispute.
ReplyDeletewell, astronomical pinpointing of location using the Rig Ved has been tried by several people and the results are varied; from NorthWest India to Anatolia with dates ranging from 3000 BC to earlier, so it seems very suspect. as for the rest, the connections are tenuous to the extreme; a figurine has a pigtail, so must be a Vedic priest. Another figurine has no head,so must be a character described in one particular scripture! a bird motif..must be Garuda ... amazing... :)
ReplyDeleteNice, balanced and informative post. You might find this interesting, plus the fact that the Rakhigarhi aDNA results are coming within weeks if not days.
ReplyDeletehttp://eurogenes.blogspot.com.au/2016/01/the-poltavka-outlier.html
thanks Davidski for the link... i do follow your blog! :) .. yes looking forward to the Rakhigarhi results..
ReplyDeleteIt's pretty obvious that the ANI-component is the Dravidian Harappans. If not Dravidian, where are the ANI-loans? If the Harappans were not the ANI, then a major population lived in the north, mixed with southerns, but did not come into contatc with the Indo-Europeans.
ReplyDeleteAccording to Underhill (2014), R1a came from Iran. And according to Gallego Romero (2011), lactose-toelrance also came from the west. Two waves of admixture: first the Dravidian Harappans who started to colinialise southern India; a millennium after this onset a second wave, with Indo-European elements, which had mixed with the post-Harappan population. No blood-thirsty invaders, but herders who lived side by side with the (post) Harappans, and mixed with the upper classes of the (post) Harappans.
Anon- I agree with you. ANI is a broad term that includes layers of Eurasian ancestry..
ReplyDelete