Unveiling the Genetic History of the Maniq, a primary hunter-gatherer society

Hunter-gatherer genetics research: Importance and avenues

Major developments in the field of genetics in the past few decades have revolutionised notions of what it means to be human. Although currently only a few populations around the world practise a hunting and gathering lifestyle, this mode of subsistence has characterised members of our species since its very origins and allowed us to migrate across the planet. Therefore, the geographical distribution of hunter-gatherer populations, dependence on local ecosystems and connections to past populations and neighbouring groups have provided unique insights into our evolutionary origins. However, given the vulnerable status of hunter-gatherers worldwide, the development of the field of anthropological genetics requires that we reevaluate how we conduct research with these communities. Here, we review how the inclusion of hunter-gatherer populations in genetics studies has advanced our understanding of human origins, ancient population migrations and interactions as well as phenotypic adaptations and adaptability to different environments, and the important scientific and medical applications of these advancements. At the same time, we highlight the necessity to address yet unresolved questions and identify areas in which the field may benefit from improvements.

More than a decade of genetic research on the Denisovans

Denisovans, a group of now extinct humans who lived in Eastern Eurasia in the Middle and Late Pleistocene, were first identified from DNA sequences just over a decade ago. Only ten fragmentary remains from two sites have been attributed to Denisovans based entirely on molecular information. Nevertheless, there has been great interest in using genetic data to understand Denisovans and their place in human history. From the reconstruction of a single high-quality genome, it has been possible to infer their population history, including events of admixture with other human groups. Additionally, the identification of Denisovan DNA in the genomes of present-day individuals has provided insights into the timing and routes of dispersal of ancient modern humans into Asia and Oceania, as well as the contributions of archaic DNA to the physiology of present-day people. In this Review, we synthesize more than a decade of research on Denisovans, reconcile controversies and summarize insights into their population history and phenotype. We also highlight how our growing knowledge about Denisovans has provided insights into our own evolutionary history.

South Asian maternal and paternal lineages in southern Thailand and the role of sex-biased admixture

Previous genome-wide studies have reported South Asian (SA) ancestry in several Mainland Southeast Asian (MSEA) populations; however, additional details concerning population history, in particular the role of sex-specific aspects of the SA admixture in MSEA populations can be addressed with uniparental markers. Here, we generated ∼2.3 mB sequences of the male-specific portions of the Y chromosome (MSY) of a Tai-Kadai (TK)-speaking Southern Thai group (SouthernThai_TK), and complete mitochondrial (mtDNA) genomes of the SouthernThai_TK and an Austronesian (AN)-speaking Southern Thai (SouthernThai_AN) group. We identified new mtDNA haplogroups, e.g. Q3, E1a1a1, B4a1a and M7c1c3 that have not previously reported in Thai populations, but are frequent in Island Southeast Asia and Oceania, suggesting interactions between MSEA and these regions. SA prevalent mtDNA haplogroups were observed at frequencies of ~35-45% in the Southern Thai groups; both of them showed more genetic relatedness to Austroasiatic (AA) speaking Mon than to any other group. For MSY, SouthernThai_TK had ~35% SA prevalent haplogroups and exhibited closer genetic affinity to Central Thais. We also analyzed published data from other MSEA populations and observed SA ancestry in some additional MSEA populations that also reflects sex-biased admixture; in general, most AA- and AN-speaking groups in MSEA were closer to SA than to TK groups based on mtDNA, but the opposite pattern was observed for the MSY. Overall, our results of new genetic lineages and sex-biased admixture from SA to MSEA groups attest to the additional value that uniparental markers can add to studies of genome-wide variation.