Genomic detection of a secondary family burial in a single jar coffin in early Medieval Korea

Objectives Family relationship is a key to understand the structure of past societies but its archeological reconstruction mostly stays circumstantial. Archaeogenetic information, especially genome-wide data, provide an objective approach to accurately reconstruct the familial relationship of ancient individuals, thus allowing a robust test of an archaeology-driven hypothesis of kinship. In this study, we applied this approach to disentangle the genetic relationship of early Medieval individuals from Korea, who were secondarily co-buried in a single jar coffin. Materials and Methods We obtained genome-wide data of six early Medieval Korean individuals from a jar coffin. We inferred the genetic relatedness between these individuals and characterized their genetic profiles using well-established population genetics methods. Results Congruent with the unusual pattern of multiple individuals in a single jar coffin, genome-wide analysis of these individuals shows that they form an extended family, including a couple, their two children and both paternal and maternal relatives. We show that these early Medieval Koreans have a genetic profile similar to present-day Koreans. Discussion We show that an unusual case of the secondary multiple burial in a single jar coffin reflects family relationship among the co-buried individuals. We find both paternal and maternal relatives co-buried with the nuclear family, which may suggest a family structure with limited gender bias. We find the genetic profile of early Medieval Koreans similar to that of present-day Koreans, showing that the genetic root of the present-day Koreans goes back at least 1500 years in the Korean peninsula.Y