Thread by @tuffimitten

The male-biased migrations of Indo-Europeans across Eurasia during the Bronze Age is well known.

But this 2021 paper explores possible Steppe female migrations into India through mtDNA analysis.

A short thread of my takeaways (as a layman):

nature.com/articles/s4143…

1) Haplogroups H2a1a,J1b1a1,U4a1 and W3a1 are the genetic legacy of the Indo-Iranian migration into India.

For instance, U4a1 and W3a1 are present in BA Yamnaya, IA Swat valley as well as in modern populations in E-Europe, C-Asia and India and Thailand. (see A in following pic)

2) Today, these haplogroups comprise 8.4% of the gene pool in North Pakistan and 1.7% in mainland India

To put in perspective,the paternal Y-DNA haplogroup R1a-Z93 (a reliable marker of Indo-Iranians since 3000BCE) alone averages 20% in India and up to 80% in some groups.

3) Among these, W3a1 and its sub-clades are by far the most ubiquitous Steppe mtDNA haplogroups found in Indian and Thai databases.

4) Regional variation of W3a1's sub-clades:

W3a1a and sub-clades - Prehistoric Yamnaya, Europe, Pakistan

W3a1b and sub-clades - Prehistoric Swat valley, Pakistan, mainland India and Thailand

(see previous pic)

5) Diversification of W3a1b into sub-clades happened in India between 2100-1500 BCE.

6) Some additional speculation from my side:

Could W3a1 have been a prominent Steppe maternal lineage involved in the southward expansion of Indo-Aryans from N.W India to the rest of India between 2000-1000 BCE ?

7) Indian migration to SE Asia happened >1000 years later. W3a1 seems to be also be the only I-Ir Steppe lineage in Thailand.

So was W3a1 a prominent or elite maternal lineage among prehistoric Hindus analogous to the paternal lineage R1a-Z93, albeit to a much lesser degree?

8) The male-biased migrations and skew of paternal haplogroups are easily explained by gotra-like concepts in Hinduism.

Is there an analogous, but weak, mechanism through which a maternal lineage could have maintained its status across centuries or even millenia ?

Would love to have your critique, comments and observations @blog_supplement @shrikanth_krish @arya_amsha @agnimaan @razibkhan @GhorAngirasa