Diffusion of yDna J2 into the Indian subcontinent

[Angela]

Dissecting the influence of Neolithic demic diffusion on Indian Y-chromosome pool through J2-M172 haplogroup

See:
http://www.nature.com/articles/srep19157

The authors actually think some of it is older than the Neolithic.

Abstract

"The global distribution of J2-M172 sub-haplogroups has been associated with Neolithic demic diffusion. Two branches of J2-M172, J2a-M410 and J2b-M102 make a considerable part of Y chromosome gene pool of the Indian subcontinent. We investigated the Neolithic contribution of demic dispersal from West to Indian paternal lineages, which majorly consists of haplogroups of Late Pleistocene ancestry. To accomplish this, we have analysed 3023 Y-chromosomes from different ethnic populations, of which 355 belonged to J2-M172. Comparison of our data with worldwide data, including Y-STRs of 1157 individuals and haplogroup frequencies of 6966 individuals, suggested a complex scenario that cannot be explained by a single wave of agricultural expansion from Near East to South Asia. Contrary to the widely accepted elite dominance model, we found a substantial presence of J2a-M410 and J2b-M102 haplogroups in both caste and tribal populations of India. Unlike demic spread in Eurasia, our results advocate a unique, complex and ancient arrival of J2a-M410 and J2b-M102 haplogroups into Indian subcontinent."

 

[Fire Haired14]

Some(EDIT: Not Referring to the paper of this thread) don't understand......

Just because Neolithic came from West Asia and J2 peaks there today, doesn't mean most J2 out of West Asia is from the expansion of farming. This idea lead to bad theories before aDNA. We already found J2 in CHG hunter gatherer, won't be surprised if J2 in South Asia has absolutely nothing to do with farming and arrived before farming was even invented.

 

[Angela]

The distribution maps of J2 (and J1) are very interesting, but some of their conclusions don't make sense to me. Maybe it's just too late.

http://www.nature.com/articles/srep19157/figures/1

http://www.nature.com/articles/srep19157/figures/2

 

[Angela]

Some don't understand......

Just because Neolithic came from West Asia and J2 peaks there today, doesn't mean most J2 out of West Asia is from the expansion of farming. This idea lead to bad theories before aDNA. We already found J2 in CHG hunter gatherer, won't be surprised if J2 in South Asia has absolutely nothing to do with farming and arrived before farming was even invented.

Fire-Haired, read the paper carefully before you draw a conclusion like that...

From the paper:

"Most likely events responsible for the current distribution of J2-M172 sublineages into Indian subcontinent could be any combination of 1) entry of herders from West and Central Asia/Middle East during late glacial maximum (LGM) of Holocene, 2) Neolithic demic diffusion from the West, and 3) Bronze and Iron age migration/admixtures."

 

[Fire Haired14]

I wasn't saying the paper makes the assumption J2=Neolithic. I was saying "some do". I should have made that clear.

 

[LeBrok]

The distribution maps of J2 (and J1) are very interesting, but some of their conclusions don't make sense to me. Maybe it's just too late.

http://www.nature.com/articles/srep19157/figures/1

http://www.nature.com/articles/srep19157/figures/2

Just eyeballed the maps. J2a-M410 has similar distribution to R1a-Z93. Possibly took part in Bronze Age IE expansion in Asia. Doesn't look Neolithic expansion or its high numbers in Anatolia would have been brought to Neolithic Europe. Well, not till Late Neolithic maybe.

J2b-M102 and M241, seems like very late founder effect explosive growth. It is unusual, at high 40% levels, but very local without radiating, unlike old haplogroups do. If it is ancient, then it is really weird how secluded and immobile this population was.

J2b-M205 could be ancient herder population, with lates founder effect in Balkans. Maybe Alexander the great army planted few seeds on their way to India?

J1-M267 looks Arab with Arab expansion to Africa and Asia. Interesting host spot in Azerbaijan. Arab elite summer retreat residence in Baku on Caspian Coast.

 

[Maciamo]

From the paper:

"Most likely events responsible for the current distribution of J2-M172 sublineages into Indian subcontinent could be any combination of 1) entry of herders from West and Central Asia/Middle East during late glacial maximum (LGM) of Holocene, 2) Neolithic demic diffusion from the West, and 3) Bronze and Iron age migration/admixtures."

Talk about being clueless ! All thye find to say is that J2 could have arrived in the Indian subcontinent some time between 25,000 and 2000 years ago. Thanks for the precision. And by the way there were no herders in the Palaeolithic ! Herders are stockbreeders, not hunters. Bunch of idiots.

There conclusions aren't any more interesting.

Dispersal of J2a-M410 and J2b-M102 from Near East to NW region and further eastwards of the subcontinent seems to have unique and complex history of various known and unknown possible events. Regardless of the complexity of dispersal, NW region appears to be the corridor for entry of these haplogroups into India.

In other words they are saying that J2 entered India via the Northwest (from where else could it have been, frankly ?) and that they still have no idea of when that was.

 

[Maciamo]

Just eyeballed the maps. J2a-M410 has similar distribution to R1a-Z93. Possibly took part in Bronze Age IE expansion in Asia. Doesn't look Neolithic expansion or its high numbers in Anatolia would have been brought to Neolithic Europe. Well, not till Late Neolithic maybe.

Actually I disagree with that. J2a peaks in Pakistan and Gujarat, which are regions associated with the Indus Valley Civilisation (Harappa), while R1a peaks in Afghanistan (Pashtun), Tajikistan, Kyrgyzstan and the Ganges valley in northern India, which are the areas most associated with the Bronze Age Indo-Aryan migrations.

It is possible that some subclades of J2a were picked up by Indo-Aryans in Central Asia and brought along to India. Unfortunately this useless paper does not make any attempt to clarify that. The oldest subclade listed in the supplementary materials is J2a-Z2396 (aka PF5197), just downstream of L26>PF5160. This subclade, however is 16000 years old according to Yfull.com, so there must be plenty of subclades further down the line, but Singh et al. didn't bother to test them. They seem to rely mostly on an antiquated 17-STR testing method instead of high-resolution SNP's.

 

[LeBrok]

Actually I disagree with that. J2a peaks in Pakistan and Gujarat, which are regions associated with the Indus Valley Civilisation (Harappa), while R1a peaks in Afghanistan (Pashtun), Tajikistan, Kyrgyzstan and the Ganges valley in northern India, which are the areas most associated with the Bronze Age Indo-Aryan migrations.

It is possible that some subclades of J2a were picked up by Indo-Aryans in Central Asia and brought along to India. Unfortunately this useless paper does not make any attempt to clarify that. The oldest subclade listed in the supplementary materials is J2a-Z2396 (aka PF5197), just downstream of L26>PF5160. This subclade, however is 16000 years old according to Yfull.com, so there must be plenty of subclades further down the line, but Singh et al. didn't bother to test them. They seem to rely mostly on an antiquated 17-STR testing method instead of high-resolution SNP's.

Yes, I agree, association is very loose I might add, at best they could have been carried around by the same forces once IE got in the area.

 

[Angela]

No, it wasn't that I was too sleepy. It's either unhelpful generalizations or just questionable conclusions.

 

[Alan]

Just eyeballed the maps. J2a-M410 has similar distribution to R1a-Z93. Possibly took part in Bronze Age IE expansion in Asia. Doesn't look Neolithic expansion or its high numbers in Anatolia would have been brought to Neolithic Europe. Well, not till Late Neolithic maybe.

J2b-M102 and M241, seems like very late founder effect explosive growth. It is unusual, at high 40% levels, but very local without radiating, unlike old haplogroups do. If it is ancient, then it is really weird how secluded and immobile this population was.

J2b-M205 could be ancient herder population, with lates founder effect in Balkans. Maybe Alexander the great army planted few seeds on their way to India?

J1-M267 looks Arab with Arab expansion to Africa and Asia. Interesting host spot in Azerbaijan. Arab elite summer retreat residence in Baku on Caspian Coast.

I was almost giving you a rep up but than I saw the last comment with J1-m267. m267 is basal upstream. Every kind of J1 subclade is going to be grouped under this. That doesn't mean everyof them is realy m267. Most of the J1 among Semites falls under the P58 subclade. J1 in the Caucasus, Anatolia and the Iranian Plateau is of different origin. We have Sarmatians with J1 who are said to have belonged to the Iranic specific subclade. Nothing more is known however.

About J2a, yes it does fit very well with the distribution of R1a z93 indicating that both expanded mostly together.

 

[Alan]

Actually I disagree with that. J2a peaks in Pakistan and Gujarat, which are regions associated with the Indus Valley Civilisation (Harappa), while R1a peaks in Afghanistan (Pashtun), Tajikistan, Kyrgyzstan and the Ganges valley in northern India, which are the areas most associated with the Bronze Age Indo-Aryan migrations.

It is possible that some subclades of J2a were picked up by Indo-Aryans in Central Asia and brought along to India. Unfortunately this useless paper does not make any attempt to clarify that. The oldest subclade listed in the supplementary materials is J2a-Z2396 (aka PF5197), just downstream of L26>PF5160. This subclade, however is 16000 years old according to Yfull.com, so there must be plenty of subclades further down the line, but Singh et al. didn't bother to test them. They seem to rely mostly on an antiquated 17-STR testing method instead of high-resolution SNP's.

I partly disagree with this, the hotspot of J2a in Central Asia overlaps too good with the hotspot of z93. However in Pakistan/Northwest India the distribution overlaps well with Harrapans too. Indicating that it was probably part of both. What if Harrapans were partly R1a themselves?

 

[Maciamo]

I partly disagree with this, the hotspot of J2a in Central Asia overlaps too good with the hotspot of z93. However in Pakistan/Northwest India the distribution overlaps well with Harrapans too. Indicating that it was probably part of both. What if Harrapans were partly R1a themselves?

R1a overlaps a bit with J2 in Bacteria because Indo-Iranians overran the Oxus Civilisation before invading India. But the R1a hotspot in essentially in the mountains of Kyrgyzstan and southern Afghanistan, while the J2 hotspot is in eastern Turkmenistan, southern Uzbekistan and northern Afghanistan. So it's not that good a match.

I seriously doubt that the Harrapans were partly R1a-Z93. The Harappan Civilisation started c. 3300 BCE. That's much too early for R1a-Z93 to have reached the region. In fact, that's barely the time R1a-Z93 was formed and the TMRCA mentioned on Yfull is only 4800 years old, so 500 years after the Harappan Civilisation started. In any case, it has been proven that R1a-Z93 originated in Russia and was part of the Sintashta and Andronovo cultures, which postdate the beginning of the Harappan Civilisation respectively by 1200 years and 1500 years.