Insights into evolutionary dynamics of East Asians through Ancient DNA

Abstract

<p indent="0mm">Human origins and evolution are a principal focus of the Earth and Life Sciences. To address these important scientific subjects, the extraction, sequencing, and analysis of ancient DNA from subfossil materials and sediments has emerged as a powerful tool, forming a cutting-edge research field for the country’s innovation competitions. Ancient DNA provides unique advantages by allowing the direct observation of the changing genetic composition of ancient populations to unveil an expanding picture of the origin and evolution of humans in rich detail. Since 2010, the genomic data of ancient humans have grown exponentially, which has dramatically increased our knowledge of important questions such as the interaction between archaic humans and early modern humans, and the genetic components of past modern human lineages. However, compared to other regions worldwide, China had lagged far behind in the ancient DNA research field, and the genetic history of humans in East Asia, especially China, remained poorly understood. Before 2017, while hundreds of genomes of past Europeans and North Asians had been generated, those of East Asians were extremely limited (only four ancient human genomes had been generated from Japan), highlighting large gaps in our knowledge of past population histories between eastern and western Eurasia. In 2017, Qiaomei Fu’s research team had published the oldest East Asian genome sequenced to date, from the approximately 40000-year-old Tianyuan individual near Beijing, which opened up new prospects for the genetic study of past East Asians. Since then, they have continued to extensively sequence large numbers of ancient human genomes across different times and regions of China, including genomes from approximately 33000-to-300-year-old humans from Heilongjiang, Inner Mongolia, Shandong, Fujian, Guangxi, Xinjiang and the Taiwan Strait. This data has been used to identify the genetic characteristics of different ancient populations in East Asia, such as Basal East Asians (represented by the Tianyuan individual) and the Ancient Guangxi population (represented by the Longlin individual) which did not contribute to present-day Eurasians, as well as explore the primary ancestries of Ancient Northern East Asians and Ancient Southern East Asians, which compose the genetic makeup of East Asians today. These studies revealed the previously unknown genetic connections among past East Asians and other ancient and present-day populations in different regions of the world, elucidated the migration and interaction models of related populations, and characterized the genetic variation associated with environmental adaptations. These pioneering works have untangled the evolutionary dynamics of East Asians over a large timescale, challenged, supported, or revised several existing hypotheses, and played a significant role in a more comprehensive reconstruction of human history. The results of these studies have additionally provided important scientific value and practical significance for human microevolution and medical genetics research.