For some reason women do not seem to migrate much into South Asia. In the late 2000s I, along with others, noticed a strange discrepancy in the Y and mtDNA lineages which trace one’s direct male and female lines: in South Asia the male lineages were likely to cluster with populations to the north an west, while the females lines did not. South Asia’s females lines in fact had a closer relationship to the mtDNA lineages of Southeast and East Asia, albeit distantly.
One solution which presented itself was to contend there was no paradox at all. That the Y chromosomal lineages found in South Asia were basal to those to the west and north. In particular, there were some papers suggesting that perhaps R1a1a originated in South Asia at the end of the last Pleistocene. Whole genome sequencing of Y chromosomes does not bear this out though. R1a1a went through rapid expansion recently, and ancient DNA has found it in Russia first. But in 2009 David Reich came out with Reconstructing Indian population history, which offered up somewhat of a possible solution.
What Reich and his coworkers found that South Asia seems to be characterized by the mixture of two very different types of populations. One set, ANI (Ancestral North Indian), are basically another western or northwestern Eurasian group. ASI (Ancestral South Indian), are indigenous, and exhibit distant affinities to the Andaman Islanders. The India-specific mtDNA then were from ASI, while the Y chromosomes with affinities to people to the north and west were from ANI. In other words, the ANI mixture into South Asia was probably through a mass migration of males.
But it’s not just Y and mtDNA in this case only. A minority of South Asians speak Austro-Asiatic languages. The most interesting of these populations are the Munda, who tend to occupy uplands in east-central India. Older books on India history often suggest that the Munda are the earliest aboriginals of the subcontinent, but that has to confront the fact that most Austro-Asiatic language are spoken in Southeast Asia. There was no true consensus where they were present first.
Genetics seems to have solved this question. The evidence is building up that Austro-Asiatic languages arrived with rice farmers from Southeast Asia. Though most of the ancestry of the Munda is of ANI-ASI mix, a small fraction is clearly East Asian. And interestingly, though they carry no East Asian mtDNA, they do carry East Asian Y. Again, gene flow mediated by males.
The same is true of India’s Bene Israel Jewish community.
A new preprint on biorxiv confirms that the Parsis are another instance of the same dynamic: The genetic legacy of Zoroastrianism in Iran and India: Insights into population structure, gene flow and selection:
Zoroastrianism is one of the oldest extant religions in the world, originating in Persia (present-day Iran) during the second millennium BCE. Historical records indicate that migrants from Persia brought Zoroastrianism to India, but there is debate over the timing of these migrations. Here we present novel genome-wide autosomal, Y-chromosome and mitochondrial data from Iranian and Indian Zoroastrians and neighbouring modern-day Indian and Iranian populations to conduct the first genome-wide genetic analysis in these groups. Using powerful haplotype-based techniques, we show that Zoroastrians in Iran and India show increased genetic homogeneity relative to other sampled groups in their respective countries, consistent with their current practices of endogamy. Despite this, we show that Indian Zoroastrians (Parsis) intermixed with local groups sometime after their arrival in India, dating this mixture to 690-1390 CE and providing strong evidence that the migrating group was largely comprised of Zoroastrian males. By exploiting the rich information in DNA from ancient human remains, we also highlight admixture in the ancestors of Iranian Zoroastrians dated to 570 BCE-746 CE, older than admixture seen in any other sampled Iranian group, consistent with a long-standing isolation of Zoroastrians from outside groups. Finally, we report genomic regions showing signatures of positive selection in present-day Zoroastrians that might correlate to the prevalence of particular diseases amongst these communities.
The paper uses lots of fancy ChromoPainter methodologies which look at the distributions of haplotypes across populations. But some of the primary results are obvious using much simpler methods.
1) About 2/3 of the ancestry of Indian Parsis derives from an Iranian population
2) About 1/3 of the ancestry of Indian Parsis derives from an Indian popuation
3) Almost all the Y chromosomes of Indian Parsis can be accounted for by Iranian ancestry
4) Almost all the mtDNA haplogroups of Indian Parsis can be accounted for by Indian ancestry
5) Iranian Zoroastrians are mostly endogamous
6) Genetic isolation has resulted in drift and selection on Zoroastrians
The fact that the ancestry proportion is clearly more than 50% Iranian for Parsis indicates that there was more than one generation of males who migrated. They did not contribute mtDNA, but they did contribute genome-wide to Iranian ancestry. There are wide intervals on the dating of this admixture event, but they are consonant oral history that was later written down by the Parsis.
So there you have it. Another example of a population formed from admixture because women hate going to India.
Citation: The genetic legacy of Zoroastrianism in Iran and India: Insights into population structure, gene flow and selection.
Saioa Lopez, Mark G Thomas, Lucy van Dorp, Naser Ansari-Pour, Sarah Stewart, Abigail L Jones, Erik Jelinek, Lounes Chikhi, Tudor Parfitt, Neil Bradman, Michael E Weale, Garrett Hellenthal
bioRxiv 128272; doi: https://doi.org/10.1101/128272
I am curious as to why you used India in the title instead of South Asia. It looks a little mischievous, especially with all the media sensationalism regarding rapes in India and why it is unsafe for foreign women tourists. But maybe you meant no mischief.
A few observations:-
1. We might as well say that South Asian women did not like to venture out of South Asia, going by the fact that Indian mtDNA M subclades are found so little outside of South Asia. It might be even said that the dislike for South Asian women towards venturing out was even greater than the dislike of non-South Asian women in coming to South Asia – we know that the so-called West Eurasian mtDNA makes up about 20 % or more of mtDNA diversity in South Asia and its spread is across the length and breadth of South Asia.
This argument is ofcourse built on the premise that all so-called West Eurasian mtDNA present in South Asia is intrusive and couldn’t possibly have originated in South Asia – a premise I do not hold to be true.
2. R1a has been found in Mesolithic Russia because we’ve had aDNA samples from that region. But without having aDNA from South Asia, we cannot give out the verdict that it was devoid of R1a in ancient times. An early presence in Russia does not prove its non-presence in other regions at that time – unless we have sufficient aDNA from those regions. We’ve had significant aDNA from Europe and therefore we can be justified in arguing that y-dna R1a was not present in Europe before the CWC. But such an argument cannot be made for South Asia just yet. Y-dna R along with Q are the 2 subclades most noticeably associated with ANE ancestry. South Asia has
very old divergent clades of y-dna Q and it also has R2. South Asia also has very old subclades of R1b and according to Sharma et al 2009, South Asia probably also harbours R1* & R1a* clades. Therefore let us wait until we have aDNA from South Asia.
3. As far as the Austro-asiatic intrusion is concerned, the recent paper on the Gond tribe was quite a good one, although the authors unfortunately missed a few tricks that may have given them a clear picture on whether the Gonds were originally Austro-asiatic or Dravidian.
https://www.nature.com/ejhg/journal/v25/n4/full/ejhg2016198a.html
Women love to visit, they just don’t want to settle down there. 😉
I’m pretty sure much more males came in from the start, but I remember high mortality rates for European women and children being noted by some authors. The climate and diseases on the subcontinent seem to have been harder to bear for pregnant women and small children. So selection might have been important too.
South Asia also has very old subclades of R1b and according to Sharma et al 2009, South Asia probably also harbours R1* & R1a* clades. Therefore let us wait until we have aDNA from South Asia.
i never know if you are a conscious liar or just clueless. i was referring to sharma 2009 above.
in the 2000s there was some uniparental work which might have supported ‘out of india.’ no longer. in the 8 years since 2009 we have thousands of R1a whole genome sequenced. this has given us power to look for variation in this lineage, and in south asia it ain’t. sharma et al. used less powerful methods to come to the conclusion it did.
also, if R1a did leave india it left no autosomal imprint. indians and non-indians do share a lot of ancestry, but
1) with ppls to the north an west aside from some iranians (and recent migration to the gulf) that shared ancestry is always the ANI portion. never the ASI one.
2) to the people to the east the indian ancestry is ASI+ANI, in keeping with historical traditions of indian migration.
the idea that R1a originated in india but somehow took no autosomal ancestry is implausible.
p.s. i will not post any follow up comments which are long-winded obfuscations.
p.p.s. i used ‘india’ because no one knows what south asia is, so not as good in titles….
“The fact that the ancestry proportion is clearly more than 50% Iranian for Parsis indicates that there was more than one generation of males who migrated.”
Is it completely impossible to get the same result with some sort of selection pressure? For instance, suppose that Parsis descendants who have lower proportion of Iranian genes (and look more like the locals) are more likely to fully assimilate and abandon the community?
I would like to add, most of these studies carried out lack regions where lot of admixture might have happened like “jammu and kashmir-INDIA” as well as lot of population groups are yet to evaluated, given the present scenario many of signatures might have lost or restricted to geographic barriers and conclusions based on a few samples itself may not depict true picture on Indian populations which actually is conglumeration of more than 4000 endogenous groups…so a lot is yet to be discovered and it may change the Idea of Indian ancestral population, the way we believe it.
a stupid bullshit comment.
1) reich et al. had kashmiri pandits in their samples. hdpd has burusho
2) almost all major populations have been sampled through 1K Genomes + reich + mait mepsalu group, as well as other stray analyses and private compannies (i have seen family tree DNA’s data)
so, the idea there are a ‘few samples’ is either lying or pig ignorance. there are thousands of s. asian samples that one can obtain from the public data. there are tens of thousands more in DTC companies.
whenever i post stuff like this some readers do two things
1) cite stuff from 2005 to 2010 when the research was at a state where ‘out of india’ was on the edge of not being easily refuted
2) simply make up the nature of current research
also, Jaydeepsinh above likes to sally forth in enormous streams of bullshit that i wonder are purposed toward obfuscation.
not going to tolerate.
In addition to the natural selection effects noted in the comment above, I wonder what would be the cultural selection effect.
It is well-known that some of the most north-western groups in India had (have?) the high boy:girl birth ratio. Would preferential male children from those Y-lineages result in loss of mtDNA that arrived with Y chr due to steady decline in number of daughters with each generation? So, the replacement women were all belonging to groups (rice farmers?) that didn’t have strong male child preference, even though equal number of men and women arrived initially?
Anybody looked into this and ruled it out?
possible, but i don’t think the math would work.
It is well-known that some of the most north-western groups in India had (have?) the high boy:girl birth ratio.
this is a recent phenomenon in its extreme nature. doubt this is at work. also, i don’t see any evidence that parsis practiced this.
Selection wouldn’t work out, but if the older original migrant men later took younger 2nd generation wives, it could still be a single migration.
[you’re stupid, it’s not incumbent on me to explain basic differences btwn SNP analyses/STR analyses and NGS to you if you cite the literature as if you understand it, you don’t. comments like yours just confuse people because they attempt the simulacrum of erudition.
also, to those who want me to cite studies. that’s fair, but remember you are talking to a person who pulls down data and runs his own analyses. i don’t need to rely on gatekeepers. and frankly, neither do you if you have a computer.
-Razib]
I really don’t understand the continued hostility among some South Asians (or is it really just Indians) to a large proportion of their ancestry not being in South Asia during the Mesolithic. I mean yes, I understand the Aryan migration theory was originally proposed by the British, so it reeks of colonialism. But it’s pretty clear (and will soon be much clearer) that a lot of the West Eurasian ancestry in India dates back to the (presumably Dravidian) neolithic farmers.
Most strikingly though, Europe is in almost exactly the same boat. Both subcontinents of Eurasia were initially occupied by brown-skinned hunter-gatherers. In both cases neolithic populations expanded from the Near East, mixing with the hunter-gatherers as they penetrated further into the region. And in both cases Indo-Europeans later came and upset the whole apple cart. The proportions vary slightly, but depending upon where you define Europe as beginning, modern Europeans arguably have less aboriginal ancestry than the average South Asian.
There is one more on Parsis! http://biorxiv.org/content/early/2017/04/19/128777