For my first content filled post I’m going to lay out some basics. For time being this blog will focus on West Eurasian mtTDNA. So, I want to first define exactly what West Eurasian mtDNA is so you all know what I am referring to when I say “West Eurasian mtDNA.”
Where is West Eurasia?
West Eurasia isn’t a geographic term people often use. It refers to Europe & southwest Asia which is known as the Middle East. So, when I say “West Eurasia” I mean Europe and the Middle East.
The geographic term West Eurasia is helpful to use in the study of human genetics because if you go back not too long ago the ancestry of Europeans & Middle Easterners is intertwined. By not too long ago I mean 14,000 or more years ago. Considering, humans have been around for 200,000 years that isn’t very long ago.
What makes West Eurasian mtDNA distinct from other region’s mtDNA?
A simple reason: Essentially all West Eurasians belong to a collection of mtDNA haplogroups which are essentially only found in West Eurasia.
The six foundational West Eurasian mHGs are: R0 (45ky), JT (53ky), U (48ky), N1, N2, and X. Notice I added age estimates for each (ky=a thousand years).
If you are from somewhere in West Eurasia there’s a 80-90% chance you belong to one of those six mHGs. If you are from East Asia or Sub Sahara Africa there’s a less than 1% chance you belong to one of those six mHGs. This is what makes West Eurasian mtDNA distinct.
Similarly, all Eastern Asians and North Asians and (Native) Americans, belong *mostly* to the same collection of mtDNA haplogroups essentially only found in Asia & America. And all Sub Saharan Africans belong *mostly* to the same collection of mtDNA haplogroups essentially only found in Africa.
What mHGs do West Eurasians share?
It depends on what Layer you are looking at. If you don’t know what I mean by “mtDNA Layer” find the definition on the My Methods page of this site. Here’s a recap. An mtDNA Layer is basically a collection of multiple mHGs who share a common ancestor and are equally separated from that ancestor. For example, H1a & H2a are both apart of Layer 2 of H. They both are two subclades separated from their common ancestor H.
I break down the mHGs all West Eurasians share into five mHG N Layers. mHG N is a pan-Eurasian mHG, meaning it is found in every part of Europe and Asia. mHG N is over 70,000 years old. N and its sister M were the first human mHGs born outside of Africa. All of the West Eurasian mHGs descend from mHG N, hence all of them belong to Layers under mHG N.
I define each Layer by the mHG’s age estimate not by how many subclades separated it is from N.
Below, in is a list and phylogenetic tree of the mHGs all West Eurasians share broken up into five Layers according to age. Below that in is the frequency of each Layer in mitogenome data from 13 West Eurasian populations.
Layer 1 (45ky), Layer 2 (27ky) take up close to 100% of mtDNA in all of West Eurasia. Layer 3 (17ky) takes up at least 3/4 of the mtDNA in all of West Eurasia. In Layer 4 (12ky) is where you first see percentages drop below 50%. But in Layer 4 (12ky) there’s still significant sharing between European & Miiddle Eastern populations. It takes up 50% of European and about 33% of Middle Eastern mtDNA. Layer 5 (8ky) is mostly made up of European mHGs which have a weak presence in the Middle East, they aren’t truly West Eurasian-wide mHGs.
Sharing between Europe & the Middle East disappears after 10ky. This is significant because in my next post I’ll show that 60%+ of Europeans belongs to the same collection of mHGs which date between 10ky and 6ky.
This to me is the definition of European mtDNA. European-specific subclades of West Eurasian mHGs which for the most part date between 10ky and 6ky. The only exceptions are U5, U4, U2e, and some K1 clades which are exclusive to Europe and over 15,000 years old. But all other mHGs in Europe have “close relatives” in the Middle East.
The distinction between Middle Eastern & European mtDNA is real but not as real and old as the distinction between eastern Eurasia & western Eurasia or between Africa & Eurasia.
*Lower case p means pre. As in pT2 (pre-T2) is ancestral to T2.
Layer 1 (50-40ky): R0, U, JT, N1, N2, p-X
Layer 2 (30-25k): HV, U2, U3, pU4, U5, U8 , T, J, X, W, N1a1, N1b
Layer 3 (20-15k): H, U2e, U3a, U4, U5a, K1a, pT1, pT2, J1, J2a, pJ2b1, pX2, I, N1b1, W
Layer 4 (13-10k): pH1, H2, H4, H5, H6, H7, H13a, U4a1, U4a2, U4c1, U5a1a, K1a2, K1a4, T1, T2, J1b1, J2a1a, J2b1, X2, N1b1a, I1, W6, W3a1
Layer 5 (10-6k): H1, H2a1, H13a1, U5a1a1, T1a1, T2b, T2c1, T2a1, J1b1a1
|Layer 1||Layer 2||Layer 3||Layer 4||Layer 5|