Timeline for AMH evolution in South Asia based on genetic, archaeological, climatological and linguistic evidence. Black and grey portions of the arrow represent Pleistocene and Holocene, respectively. Blue sections correspond to periods of climate changes: dryer periods between 35 and 30 ka, Last Glacial Maximum ~18 ka, Younger Dryas ~12 ka and the " 4.2 ka " event. Lineages in red stand for the putative Late Glacial/postglacial genetic influx from West Eurasia; green for migrations from West Eurasia around the Pleistocene/Holocene transition, orange for the Neolithic period and blue for the genetic events in the last 4 ka
This result suggests that an ancient western ancestry may have been disguised by further re-expansions ofhaplogroup M in South Asia. Several branches of M(M38, M65, M45, M5b, M5c, M34, M57, M33a) display signals of dispersals from the east and the centre datingt o ~45–35 ka, and M4’67 (which is only separated by asingle mutation from the root of M), with a possible origin in central India, displays an extraordinary multi-branching structure dating to 38.0 [30.1; 46.0] ka, suggesting a major expansion at that time. If we considerthat a root type of M could have survived for ~10,000 yearsafter it arose (as is evident from modern clades within thatage range), it is plausible that re-expansion created a sec-ondary founder effect within M that decreased the overallage estimates. Such a scenario would impact even moreon ρthan ML estimates, which is indeed what we see(Table 1). An expansion 45–35 ka would also fit well with the palaeoenvironmental and archaeological evidence[2, 67, 68], and is further supported by an increment inNeassociated with M across South Asia from ~40 ka(Additional file 1: Figure S1).The next major discernible signal in indigenous lineages begins ~12 ka, at the Pleistocene/Holocene transition.Various star-like clades dating 12–9 ka suggest a rapid ex-pansion across the Subcontinent, namely M6a1a (11.4 ka),M18a (9.2 ka), M30d (12.1 ka), R8b1 (11.6 ka) and U2b2(9.2 ka), all from a southern source; and R30c + 373(12.4 ka), from the west. An increment in Neis also ob-served at this time in the BSP for haplogroup M in thewest and south (Additional file 1: Figure S1).We also see a further increment in the last few millennia.BSPs for M in the west and centre show an increment inthelast2.5ka(Additionalfile1:FigureS1),associated withthe emergence of several subclades in the west (M2a3a +4314, M2a1b, M2c + 1888 + 146, M30a2, M5a3b, M6a1 +5585 + 146 + 1508) and centre (M2a1a1b, M3b, M3a1a,M63, M5a2a2 + 234, M5a3a and M61a + 5294).
West Eurasian mtDNA lineages in South Asia: Multiple dispersals from the northwest since the LGM Prehistoric West Eurasian lineages make up almost 20%of the South Asian genetic pool overall.
from A genetic chronology for the Indian Subcontinent points to heavily sex-biased dispersals Pedro Soares et all
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