Insights into the demographic history of Asia from common ancestry and admixture in the genomic landscape of present-day Austroasiatic speakers

Abstract

Background The demographic history of South and Southeast Asia (S&SEA) is complex and contentious, with multiple waves of human migration. Some of the earliest footfalls were of the ancestors of modern Austroasiatic (AA) language speakers. Understanding the history of the AA language family, comprising of over 150 languages and their speakers distributed across broad geographical region in isolated small populations of various sizes, can help shed light on the peopling of S&SEA. Here we investigated the genetic relatedness of two AA groups, their relationship with other ethno-linguistically distinct populations, and the relationship of these groups with ancient genomes of individuals living in S&SEA at different time periods, to infer about the demographic history of this region. Results We analyzed 1451 extant genomes, 189 AAs from India and Malaysia, and 43 ancient genomes from S&SEA. Population structure analysis reveals neither language nor geography appropriately correlates with genetic diversity. The inconsistency between “language and genetics” or “geography and genetics” can largely be attributed to ancient admixture with East Asian populations. We estimated a pre-Neolithic origin of AA language speakers, with shared ancestry between Indian and Malaysian populations until about 470 generations ago, contesting the existing model of Neolithic expansion of the AA culture. We observed a spatio-temporal transition in the genetic ancestry of SEA with genetic contribution from East Asia significantly increasing in the post-Neolithic period. Conclusion Our study shows that contrary to assumptions in many previous studies and despite having linguistic commonality, Indian AAs have a distinct genomic structure compared to Malaysian AAs. This linguistic-genetic discordance is reflective of the complex history of population migration and admixture shaping the genomic landscape of S&SEA. We postulate that pre-Neolithic ancestors of today’s AAs were widespread in S&SEA, and the fragmentation and dissipation of the population have largely been a resultant of multiple migrations of East Asian farmers during the Neolithic period. It also highlights the resilience of AAs in continuing to speak their language in spite of checkered population distribution and possible dominance from other linguistic groups.

Multiple migrations from East Asia led to linguistic transformation in NorthEast India and mainland Southeast Asia

“…Nevertheless, the presence of ancient Austroasiatics (AA) speakers across NEI still remains a possibility. Our previous study (Tagore et al, 2021) on autosomal data of the Mundari and Mon-Khmer Austroasiatics indicated that in pre-Neolithic times, the ancestors of today's Austroasiatic speakers had a widespread distribution possibly extending from Central India to Southeast Asia (SEA), further supported by Lipson et al (2018). They were later in time fragmented and isolated to small pockets resulting in their present-day disjoint geographic distribution.…”

“…Basu et al (2003) has shown that the TB and AA speakers of India are similar in their mtDNA profile but harbor very distinct Y-chromosomes. Our previous study (Tagore et al, 2021) observed the genetic relatedness between the Tibeto Burmans and Austroasiatic speakers (Mon Khmers) of Malaysia, because of ancient shared ancestry as well as owing to gene flow in both these populations from East Asia. Another study (Guo et al, 2022) found the present day TBs to cluster between the millet cultivators of Yellow River basin as well as the Austroasiatic speakers of Southeast Asia in a Principal Components Analysis.…”

The Peopling and Migration History of the Natives in Peninsular Malaysia and Borneo: A Glimpse on the Studies Over the Past 100 years

“…Recent investigation postulates that pre-Neolithic ancestors of today’s Austroasiatic language-speaking populations were widespread in South Asia and SEA, and the populations from these regions were the result of multiple migrations of East Asian farmers during the Neolithic period ( Tagore et al, 2021 ). The authors predicted that the present-day Austroasiatic populations from India and Malaysia shared a common ancestor until about 10.5 kya.…”

Publisher Correction to: Insights into the demographic history of Asia from common ancestry and admixture in the genomic landscape of present-day Austroasiatic speakers

“…Following publication of the original article [ 1 ], an error was identified in the ‘Availability of data and materials’ section due to a typesetting mistake: in the first sentence of this section, a citation to reference 76 was present, instead of a citation to reference 72.…”

“…The original article [ 1 ] has been updated. The publisher apologises to the authors and readers for the inconvenience caused by this mistake.…”