Saturday, August 22, 2015

Part 1: Looking For mtDNA Diversity in West Eurasia

All useful Links can be found hereAnalysis of West Eurasian mtDNA

Below is a tree showing the relationship between the 6 maternal lineages that combined reach a frequency of 80%+ in most of West Eurasia and are very rare elsewhere. The 6 lineages are: R0, R2'JT, U, N1, N2, X. I also added subclades of those lineages which are able to be identified with low coverage mtDNA testing. Click on the image to enlarge.

It can be confusing how in a region as big as West Eurasia everyone could be so related maternally. Each one of those 6 haplogroups are over 40,000 years old, therefore one would propose there must be differences within those haplogroups between differnt West Eurasians.

So, what I've done is analysed 1,000s of mtDNA samples from West Eurasia to find diversity.

Locations of my samples: Map of mtDNA samples
To look at the raw mtDNA data yourself: Haplotypes
Studies where I got my data: References 
Frequencies of Haplogroups: Haplogroup Frequencies.

Almost all my samples were tested at such low coverage that I could only dissever the subclade of 5 haplogroups U, R2'JT, R0(xH), HV(xH), and N1. For the majority of West Eurasian mtDNAs it was impossible to find diversity.

In each one of those 5 haplogroups stark differences between Europe and West Asia appeared. To display these differences I made spreadsheets of the frequencies of U, JT, and N1 subclades in West Asian and European populations.

Europe/West Asia JT+N1

Europe/West Asia U

I also made a spreadsheet showing the frequency of typical West Asian and typical European subclades of R2'JT, R0, U, and N1.

West Asian vs European mtDNA Frequencies

70%+ of West Asian/European mtDNA in the 5 haplogroups that can find a deep subclade with low coverage belong to subclades exclusive to their region(West Asia, Europe). It's very consistent.

Frequency of "Steppe" mtDNA

For fun I wanted  see what the maternal-relationship between Bronze age "Steppe" people(Yamnaya, Catacomb) is with modern/ancient West Eurasians. In my next post I'll discuss more about the possible ancestors of West Eurasian mtDNA.

There are 10 subclades that can be identified with low coverage mtDNA testing that were popular in Bronze age "Steppe" people. I made a spreadsheet showing the combined-frequency of those subclades in modern and ancient West Eurasians.

Frequency of Steppe mtDNA

Something that stood out to me is that 4/8 of Bronze age Armenian mtDNA falls under typical "Steppe" subclades. Autosomal DNA and Y DNA(R1b-Z2103) also confirm some-type of relationship between Bronze age Armenia and Steppe.

Among modern people "Steppe mtDNA" peaks in the Volga/Ural region of Russia and next in North Europe. "Steppe mtDNA" is  least popular in Iberia and West Asia. This is consistent with autosomal DNA.