The peopling of India refers to the migration of Homo sapiens into the Indian subcontinent. Anatomically modern humans settled India in multiple waves of early migrations, over tens of millennia. The first migrants came with the Coastal Migration/Southern Dispersal 65,000 years ago, whereafter complex migrations within South and Southeast Asia took place. West Asian Iranian hunter-gatherers migrated to South Asia after the Last Glacial Period but before the onset of farming. Together with ancient South Asian hunter-gatherers they formed the population of the Indus Valley Civilisation (IVC). The population of the IVC was the result of mixing between Iranian hunter gatherers and Ancient Ancestral South Indian (AASI).
With the decline of the IVC, and the migration of Indo-Europeans, the IVC-people contributed to the formation of both the Ancestral North Indians ("ANI"), who were related to contemporary West Eurasians, and the Ancestral South Indians ("ASI"), who were formed out of "Indus Periphery-related groups" who moved south and mixed further with local hunter-gatherers. These two ancestral populations, ASI and ANI, mixed somewhere between 1,900-4,200 years ago, after which a switch to endogamy took place. After the fall of the IVC there was significant southward migration of the IVC people, groups considered the ancestors of modern day Dravidians.Srinath Perur, The origins of Indians. What our genes are telling us., Fountain Ink
Quote: "Sometime between 1,900 to 4,200 years ago, profound, pervasive convulsive mixture occurred, affecting every Indo-European and Dravidian group in India without exception." The intermixing between ASI and ANI groups was substantial and affected both modern Indo-European populations as well as the Dravidian populations in the subcontinent. The migrations of the Munda people and the Sino-Tibetan-speaking people from East Asia also added new elements.
First modern human settlers
Pre- or post-Toba The dating of the earliest successful migration of modern humans out of Africa is a matter of dispute. It may have pre- or post-dated the Toba catastrophe, a volcanic super eruption that took place between 69,000 and 77,000 years ago at the site of present-day Lake Toba. According to Michael Petraglia, stone tools discovered below the layers of ash deposits in India at Jwalapuram, Andhra Pradesh point to a pre-Toba dispersal. The population who created these tools is not known with certainty as no human remains were found. An indication for post-Toba is haplogroup L3, that originated before the dispersal of humans out of Africa, and can be dated to 60,000–70,000 years ago, "suggesting that humanity left Africa a few thousand years after Toba."
Impact 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.
Pre-Toba tools 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. Recent research also by Macauly et al. (2005) and Posth et al. (2016), also argue for a post-Toba dispersal.Bradshaw Foundation, Human Migration Early Stone Age hominin fossils have been found in the Narmada valley of Madhya Pradesh. Some have been dated to 200- 700,000 BP. It is uncertain what species they represent.
Post-Toba Southern Coastal dispersal
By some 70-50,000 years ago, only a small group, possibly as few as 150 to 1,000 people, crossed the Red Sea. The group that crossed the Red Sea travelled along the coastal route around the coast of Arabia and Persia until reaching India, which appears to be the first major settling point. Geneticist Spencer Wells says that the early travellers followed the southern coastline of Asia, crossed about of sea, and colonized Australia by around 50,000 years ago. The Aborigines of Australia, Wells says, are the descendants of the first wave of migrations.
The oldest definitively identified Homo sapiens fossils yet found in South Asia are Balangoda Man. Named for the location in Sri Lanka where they were discovered, they are at least 28,000 years old.
Theories around Indigenous Aryanism are popular among certain Hindutva circles, and do not have any support in peer-reviewed literature."Hindutva thinkers propagate an Out of India theory, which stipulates that Sanskrit-speaking Aryans originated in India and from there traveled to the rest of the world. As Tony Joseph has pointed out, the Out of India theory lacks support from even "a single, peer-reviewed scientific paper" and is best considered nothing "more than a kind of clever and angry retort."
AASI Narasimhan et al. (2018) introduced the term AASI, "Ancient Ancestral South Indian" (AASI) for these oldest human inhabitants, which were possibly distantly related to the common ancestors of East-Eurasians such as Andaman Islanders (such as the Onge), East Asians, and Australian Aboriginals. According to Narasimhan et al. (2019), "essentially all the ancestry of present-day eastern and southern Asians (prior to West Eurasian-related admixture in southern Asians) derives from a hypothetical single eastward spread, which gave rise in a short span of time to the lineages leading to AASI, East Asians, Onge, and Australians.", a lineage often referred to as "East-Eurasians".
Relation to Andaman Islanders
Several genetic studies have found evidence of a distant common ancestry between native Andaman Islanders and the AASI/ASI ancestral component found in South Asians. Modern South Asians have not been found to carry the paternal lineages common in the Andamanese, which has been suggested to indicate that certain paternal lineages may have become extinct in India, or that they may be very rare and have not yet been sampled. Chaubey and Endicott (2013) further noted that "Overall, the Andamanese are more closely related to Southeast Asian Negritos than they are to present-day South Asians."
Shinde et al. 2019 found either Andamanese or East Siberian hunter-gatherers fit as proxy for AASI "due to shared ancestry deeply in time." According to Yelmen et al. (2019) the native South Asian genetic component (AASI) is distinct from the Andamanese and not closely related, and that the Andamanese are thus an imperfect and imprecise proxy for AASI. According to Yelmen et al, the Andamanese component (represented by the Andamanese Onge) was not detected in the northern Indian Gujarati, and thus it is suggested that the South Indian tribal Paniya people (who are believed to be of largely AASI ancestry) would serve as a better proxy than the Andamanese (Onge) for the "native South Asian" component in modern South Asians.
According to Narasimhan et al. (2019), the "AASI" component in South Asians shares a common root with the Andamanese (as exemplified by the Onge) and is distantly related to the Onge (Andamanese), as well as to East Asians, and Aboriginal Australians (with those groups and the AASI sharing a deep ancestral split around the same time), which would place them in the East-Eurasian lineage.
Relation to "Negritos"
The present-day Andamese are considered to be part of the "Negritos", several diverse ethnic groups who inhabit isolated parts of southeast Asia.Snow, Philip. The Star Raft: China's Encounter With Africa. Cornell University Press, 1989 () Based on their physical similarities, Negritos were once considered a single population of related people, but the appropriateness of using the label 'Negrito' to bundle together peoples of different ethnicity based on similarities in stature and complexion has been challenged. Recent research suggests that the Negritos include several separate groups, as well as demonstrating that they are not closely related to the Pygmies of Africa.S. Noerwidi, "Using Dental Metrical Analysis to Determine the Terminal Pleistocene and Holocene Population History of Java", in: Philip J. Piper, Hirofumi Matsumura, David Bulbeck (eds.), New Perspectives in Southeast Asian and Pacific Prehistory (2017), p. 92.
According to Vishwanathan et al. (2004), the typical "negrito" features could also have been developed by convergent evolution. According to Gyaneshwer Chaubey and Endicott (2013), "At the current level of genetic resolution, however, there is no evidence of a single ancestral population for the different groups traditionally defined as 'negritos'." Basu et al. 2016 concluded that the Andamanese have a distinct ancestry and are not closely related to other South Asians, but are closer to Southeast Asian Negritos, indicating that South Asian peoples do not descend directly from "Negritos" as such.
Sri Lankan Vedda
Groups ancestral to the modern Veddas were probably the earliest inhabitants of Sri Lanka. Their arrival is dated tentatively to about 40,000–35,000 years ago. They are genetically distinguishable from the other peoples of Sri Lanka, and they show a high degree of intra-group diversity. This is consistent with a long history of existing as small subgroups undergoing significant genetic drift.
A 2013 study by Raghavan et al. showed that the Vedda are closely related to other groups in Sri Lanka and India, especially to Sinhalese and Tamils. They additionally found deep relations between the indigenous Vedda and other South Asian populations with the modern populations of Europe, the Middle East and Northern Africa.
Latest Glacial Maximum
After the Last Glacial Period, human populations started to grow and migrate. With the invention of agriculture, the so-called Neolithic revolution, larger numbers of people could be sustained. The use of metals (copper, bronze, iron) further changed human ways of life, giving an initial advance to early users, and aiding further migrations, and admixture.
According to Silva et al. (2017), multiple waves of migration from western Eurasia took place after the last Ice Age, both before and after the advent of farming in South Asia. According to Narasimhan et al. (2019), people related to Iranian hunter-gatherers were present in South Asia before the advent of farming. They mixed with Ancestral Ancient South Asians (AASI) to form the Indus Valley population. With the decline of the IVC after 1900 BCE and the arrival of the Indo-Aryans, IVC-people mixed with incoming Indo-Aryans, forming the Ancestral North Indians (ANI). Other IVC-people mixed with AASI forming the Ancestral South Indians (ASI).