1000genomes - Sri Lankan Tamils in the UK (STU) data

The 1000 Genomes Project (abbreviated as 1KGP), launched in January 2008, was an international research effort to establish by far the most detailed catalogue of human genetic variation.

Scientists sequenced the genomes of at least 1000 anonymous participants from a number of different ethnic groups including over 100 Sri Lankan Tamils in the UK (STU).

Initially, over 100 Sinhalese in the UK were also have meant to have been sampled, but for reasons unknown this was cancelled.

The data from the 1000genomes project shows significant genetic variation within the Tamil samples (plotted in black on the below chart), with some individuals clearly being of Dalit background (labelled below as S.C - scheduled caste and represented as a black triangle).

Plot courtesy of geneticist Razib Khan. Annotations added. 

(As you go up the cline, the amount of indigenous South Asian hunter gatherer DNA increases. The Bangladeshis are shifted to the right of the cline due to East Asian admixture.)

This furthers highlights the need for future genetic studies on Sri Lanka to take into account caste and region, as there is much genetic variation within the same ethnic group. Taking a single average of all these divergent castes hides an underlying complexity.

Average results from 1000 genomes project. Courtesy of geneticist Razib Khan.