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Ancestries in corona times

Tensing Rodrigues

The title of this article may indeed sound off the topic; or a symptom of the corona fixation that seems to have spread virulently; nothing of the sort. Today I would like to share with you a recent, and a rare, study to investigate the association between the genetic ancestries and the probability of COVID-19 manifestation. The purpose is not to disseminate further information on COVID-19. The study is read in the context of our long investigation of the probable genetic roots of the komkni people. Many have found the obsession with the ancestries unjustified, because ultimately the ancestries translate into ‘castes’. We have consistently held that the two are entirely different concepts; caste is an essentially hierarchical concept and therefore divisive; as against this ancestries which link us objectively to the different groups, and therefore are essentially unifying.

The genetic study, the first of its type I know of, is by Ranajit Das and Sudeep Ghate of Yenepoya Research Centre, Mangaluru, Karnataka, published on April 5, 2020. [Das & Ghate, 2020: Investigating The Likely Association Between Genetic Ancestry And COVID-19 Manifestation, medRxiv preprint, https://doi.org/10.1101/2020.04.05 .20054627] Being sort of a forerunner, it has the shortcoming of being preliminary; its results have to be corroborated by further studies. Also, it is based on publicly available data, and not on detailed analysis of individual genomic sequence data from COVID-19 patients of varied ancestries. Genome data for the study was obtained from the personal database of Dr David Reich’s Lab, Harvard Medical School, USA; the final dataset comprised of 10,215 ancient and modern genomes across the globe assessing 597,573 single nucleotide polymorphisms. COVID-19 data was obtained from 2019 Novel Coronavirus COVID-19 (2019-nCoV) Data Repository by Johns Hopkins CSSE, data as on April 5, 2020. Indian data was obtained from Government of India coronavirus portal. In spite of its methodological shortcomings, it merits attention because it is by pure geneticists, who do not have any social, political or commercial bias.

Let us go straight to what matters to us; we shall be reading it in the context of the ethnic composition of the komkni people. You can find a broad picture of the komkni mosaic in ‘We The People of Komkan’ (May 3, 2020). The komkni people have “a long and complex history of admixture between immigrant gene-pools originating primarily in West Eurasia, Southeast Asia and the South Asian hunter-gatherer lineage”. Now let us connect these terms to what we have discussed up to now.

‘South Asian hunter-gatherer lineage’ refers to the descendants of the first modern humans out of Africa who likely arrived in India around 60,000 to 40,000 BCE. They have been named Ancient Ancestral South Indians (AASI). These could be the ancestors of the vetuvan or vedar found on the south eastern tip of the Indian peninsula and Sri Lanka, and possibly through them of the modern tamil. As of now we do not have any evidence of these earliest settlers in Komkan, even in the extended or trans-Sahyadri Komkan that we have called the Brhatkomkan; they could have been pushed out by the subsequent waves.

‘Immigrant gene-pools originating in West Eurasia’ refers to those who migrated from Near East (Iran, etc) and those who migrated from Central Asian Steppes between 8,000 BCE and 2,000 BCE. Together they have been named Ancestral North Indian (ANI). Those who migrated from Near East we have called ksatriya; and those who migrated from Central Asian Steppes we have called bramhan. The admixture of AASI and the ksatriya component of ANI gave rise to the Ancestral South Indian (ASI) ancestry; this we have called the Deccan ksatriya.

In the meantime two other ancestries entered the Indian sub-continent: Ancestral Tibeto-Burman (ATB) and Ancestral Austro-Asiatic (AAA). They could be the result of a migration from South East Asia and China, across the northeastern frontier near the India-China-Myanmar border around 6,000 BCE; we have called these people kirat. The admixture between kirat and the ksatriya component of ANI could have given rise to AAA. We do not find much of kirat ancestry in komkani population, except in one specific community, that is the kathiyavadi ksatriya. So, we find four prominent ancestries in the komkani population: AASI (ASI), ANI (ksatriya), ANI (bramhan) and AAS (kathiyavadi ksatriya).

Now the association with COVID-19 manifestation. The genomic proximity between East Asians and South Asians mostly from Northeast India with prominent ATB ancestry is probably reflected in fewer numbers of COVID-19 cases from this region; as on the date of submission of the research paper, one case each in Arunachal Pradesh and Mizoram, and two in Manipur. Notably the death to recovery ratio in the largely ATB dominated region of Ladakh is zero, indicating complete recovery so far of COVID-19 infected individuals from this region. As against this in its neighboring state of Jammu and Kashmir with predominant ANI ancestral fractions the ratio is discernibly higher (0.5). Further, Indian states with large number of indigenous tribal population with prevalence of AAA ancestry and/or with large fractions of AASI – related ancestry, eg: Chhattisgarh, Jharkhand and Orissa have not registered any COVID related deaths till date, indicating that South Asians with dominant AAA and AASI related ancestry may also likely be less severely affected. Approximately 12 per cent people of ANI and ASI ancestries belong to mitochondrial haplogroup U coming from the European Mesolithic hunter gatherers (WHGs) (bramhan) populations. This is likely associated with acute COVID-19 manifestation and is predictive of debilitating effects of COVID-19 infection among South Asian populations with substantial fractions of WHG ancestry. Overall COVID-19 manifestation in South Asia is likely to be somewhat intermediate to that observed in Europe and East Asia. This is underscored by the recent finding that allele frequencies of ACE2 gene variants among South Asians are intermediate between East Asians and Europeans; ACE2 gene has been speculated to be the host receptor for the novel coronavirus.

The purpose of this article is not to help us to estimate how prone we are to COVID-19 infection; the purpose is strictly to help us to drive home the fundamental difference between ‘caste’ as a criterion for categorisation and the ‘ancestry’ as the criterion, even when the two overlap. Caste is an artificial construct created by one or more communities to organise the rest of the population around it in a neat and useful manner. As against this, ethnic categories based on ancestry or genetic characteristics are a natural phenomenon amenable to scientific study.

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