The Pith: Afro-Indians are mostly African, with a substantial Indian minority ancestry. The latter is disproportionately female mediated. It also seems that that ancestry is more northwest Indian, and that natural selection has been operating upon them outside of the African environment.
Along the western coast of South Asia, from Makran in southwest Pakistan, down to the Konkan coast of southwest Iindia, there are isolated communities of Afro-Indians. They are called Siddis or Habshi. Their African origin is clear in their physical appearance, as well as aspects of their folk customs which tie them back to Sub-Saharan African. Nevertheless, they have assimilated to many Indian cultural traits. They generally speak the local language, and practice Islam, Hinduism, or Roman Catholic Christianity (in that order in proportion).
How and why did the Siddis arrive in India? The earliest date for their arrival almost certainly must be bounded by the period when Indo-Islamic polities rose to prominence in the early second millennium. The cosmopolitan melange of the armies of the Muslim warlords included diverse groups of Africans, some of whom took power, and established their own self-conscious Afro-Indian dynasties, set apart from the Turkish, Afghan, Persian, and Arab inflected statelets. Were these the sources of the modern Siddi communities? The oral history of the Siddi of the western coast of South Asia suggests not. In fact the geographical concentration of these Afro-Indian tribes along the Arabian sea fringe is indicative of different historical actors: the Portuguese. In much of Asia, out to China, the role of Africans was very different from that in the New World. They were objects purchased as for elite consumption, not production. They served at court, guarded the harem, etc. Lowland Asia had no need for imported labor, as there was human stock aplenty. Whereas in much of the New World black African slaves were critical cogs in the capitalist system of production, in Asia, as in the Arab world outside of a few areas such as southern Iraq, they were signals of luxurious consumption by the high and mighty (this was in vogue at European courts for a period as well).
Two new papers published yesterday in the American Journal of Human Genetics examine the genetics of the Siddi of India with an eye toward elucidating the details of their historical ethnogenesis. Though the papers overlap to a great extent, there are subtle differences which result in complementation. Shah et al. uses a far thicker set of markers, while Narang et al. look at many more populations, but due to removing SNPs which don’t span their populations the marker set is much thinner. Let’s review the papers in turn.