Peopling of India

See also: Genetics and archaeogenetics of South Asia

The peopling of India refers to the migration of Humans and Humanoids into India. Evidence of humanoid population in India may stretch as far back as 1,500,000 years before today but the earliest ancestors of the modern human population of India are believed to be the ancestors of the Andamanese people of the Andaman Islands. The is a contentious area of research and discourse, due to the debate on topics such as the Indo-Aryan migration theory. Some anthropologists hypothesize that the region was settled by multiple human migrations over tens of millennia, which makes it even harder to select certain groups as being aboriginal.

Early hominins of Acheulean period

The presence of intelligent hominins in the subcontinent may stretch as far back as 1,500,000 ybp to the Acheulean period.

Humans and the Toba catastrophe

It has been hypothesized that the Toba supereruption about 74,000 years ago destroyed much of India's central forests, covering it with a layer of volcanic ash, and may have brought humans worldwide to a state of near-extinction by suddenly plunging the planet into an ice-age that could have lasted for up to 1,800 years. If true, this may "explain the apparent bottleneck in human populations that geneticists believe occurred between 50,000 and 100,000 years ago" and the relative "lack of genetic diversity among humans alive today."

Since the Toba event is believed to have had such a harsh impact and "specifically blanketed the Indian subcontinent in a deep layer of ash," it was "difficult to see how India's first colonists could have survived this greatest of all disasters." Therefore, it was believed that all humans previously present in India went extinct during, or shortly after, this event and these first Indians left "no trace of their DNA in present-day humans" - a theory seemingly backed by genetic studies.

Research published in 2009 by a team led by Michael Petraglia of the University of Oxford suggested that some humans may have survived the hypothesized catastrophe on the Indian mainland. Undertaking "Pompeii-like excavations" under the layer of Toba ash, the team discovered tools and human habitations from both before and after the eruption. However, human fossils have not been found from this period and nothing is known of the ethnicity of these early humans in India.

The Negrito migrations

Migrations routes according to the Coastal Migration Model

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Note the route of the mtDNA Haplogroup M through the Indian subcontinent, to Andaman Islands and Southeast Asia.

Note the route of the Y-DNA Haplogroup C through the Indian subcontinent to Australia.

Y-DNA Haplogroup F and it's descendants.

The Andamanese are believed to be descended from the migrations which, about 60,000 years ago, brought the first modern humans out of Africa to the Andaman Islands. One narrative, describes Negritos, similar to the Andamanese adivasis of today, as the first identifiable human population to colonize India, likely 30-65 thousand years before present (kybp). This first colonization of the Indian mainland and the Andaman Islands by humans is theorized to be part of a great coastal migration of humans from Africa along the coastal regions of the Indian mainland and towards Southeast Asia, Japan and Oceania.

Andamanese women carry M32 mtDNA, which is unique and universal among Andamanese islander, other variants of the mtDNA haplogroup M is found 60% of all modern South Asians and might be a genetic legacy of the postulated first settlers. A 2010 study by the Anthropological Survey of India and the Texas-based Southwest Foundation for Biomedical Research identified seven genomes from 26 isolated "relic tribes" (sic) from the Indian mainland, such as the Baiga, which share "two synonymous polymorphisms with the M42 haplogroup, which is specific to Australian Aborigines." These were specific mtDNA mutations that are shared exclusively by Australian aborigines and these Indian tribes, and no other known human groupings.

Hypothesized Australoid migrations

Some anthropologists theorize that the original Negrito settlers of India were displaced by invading Austroasiatic-speaking Australoid people (who largely shared skin pigmentation and physiognomy with the Negritos, but had straight rather than kinky hair), and adivasi tribes such as the Irulas trace their origins to that displacement. The Oraon adivasi tribe of eastern India and the Korku tribe of western India are considered to be examples of groups of Australoid origin.

Caucasoid and Mongoloid migrations

Subsequent to the Australoids, some anthropologists and geneticists theorize that Caucasoids (including both Dravidians and Indo-Aryans) and Mongoloids (Sino-Tibetans) immigrated into India: the Elamo-Dravidians possibly from Iran, the Indo-Aryans possibly from the Central Asian steppes and the Tibeto-Burmans possibly from the Himalayan and north-eastern borders of the subcontinent.

Crossovers in languages and ethnicity

One complication in studying various population groups is that ethnic origins and linguistic affiliations in India match only inexactly: while the Oraon adivasis are classified as an Australoid group, their language, called Kurukh, is Dravidian. Khasis and Nicobarese are considered to be Mongoloid groups and the Munda and Santals are Australoid groups, but all four speak Austro-Asiatic languages. The Bhils and Gonds are frequently classified as Australoid groups, yet Bhil languages are Indo-European and the Gondi language is Dravidian.

See also

• Genetics and archaeogenetics of South Asia
• Early human migrations
• Andamanese
• Negrito
• Australoid race
• Irulas
• Indo-Aryan migration hypothesis