A recent study analyzed the genetic ancestry of Japanese populations by utilizing 22 ancient genomes alongside 171,287 modern genomes from Biobank Japan.

The research identified 132 genetic variants linked to Jomon ancestry, which are notably more prevalent in Japanese populations, especially among those from the Ryukyu Islands, suggesting recent selective pressures.

These findings underscore the significant role of ancient Jomon ancestry in shaping the genetic landscape and phenotypic traits of contemporary Japanese populations.

The Yayoi period, spanning from approximately 3,000 to 1,700 years ago, saw the introduction of rice cultivation by continental immigrants, which catalyzed sociopolitical changes and the emergence of the Japanese state during the Kofun period.

Anatomically modern humans began migrating from Africa between 50,000 and 60,000 years ago, reaching East Asia around 40,000 to 50,000 years ago, leading to significant lifestyle shifts due to interactions with incoming farmers.

The Japanese archipelago has been inhabited since at least 38,000 years ago, with the Jomon culture, known for its early pottery, emerging around 16,500 years ago and lasting until approximately 3,000 years ago.

Historically, the origins of Japanese populations were understood through a dual-ancestral model, combining indigenous Jomon hunter-gatherers with immigrant farmers from Northeast Asia.

However, recent studies propose a tripartite model that includes a third ancestral component from East Asia, which better explains the genetic diversity observed in various Japanese populations.

This tripartite model reveals regional variations in Jomon ancestry proportions, ranging from 9.8% in Kinki to 26.1% in Okinawa.

Furthermore, Jomon ancestry has been significantly associated with phenotypic traits, particularly body mass index (BMI), indicating a connection between ancient ancestry and modern health outcomes.