Japan's Jomon People Developed Unique Genetic Cold Adaptations, Science Advances Reveals

The Jomon: Pioneers of Genetic Cold Adaptation

The Jomon people, a prehistoric culture that occupied the Japanese archipelago almost continuously for nearly 14,000 years (approximately 16,000 to 2,300 BCE), developed specific genetic adaptations to cold remarkably distinct from those of other high-latitude populations, according to a study published in August 2026 in the journal Science Advances.¹ Comparative analysis of ancient Jomon genomes with contemporary Siberian, Inuit, and Arctic hunter-gatherer populations reveals that the Jomon took their own genetic pathways to adapt to the archipelago's harsh winters, offering a fascinating example of evolutionary convergence: geographically separated populations can arrive at superficially similar but genetically distinct biological solutions.

The Jomon are one of the most remarkable and least-known prehistoric cultures in the world. Hunter-gatherer-fishers, they developed a sophisticated material culture including the oldest known pottery to date (dated to approximately 16,000 BCE), permanent wooden dwellings, elaborate ornaments, and complex funerary practices. Unlike many other prehistoric hunter-gatherer cultures, the Jomon did not spontaneously transition to agricultureAgricultureThe cultivation of plants and production of food by working the soil, which emerged in the Neolithic in the Near East and independently elsewhere; it radically transformed human societies.→: it was migratory waves of farming peoples from continental China (the ancestors of the Yayoi) that progressively transformed the archipelago's genetic and cultural composition from around 2,500 BCE.

Genetic Variants of Thermal Adaptation

The international team led by Takashi Gakuhari (Kanazawa University) and Johannes Krause (Max Planck Institute, Leipzig) sequenced the genomes of 47 Jomon individuals from archaeological sites distributed across the archipelago, covering a period of 9,000 to 2,500 BCE. These genomes were compared with those of 89 present-day and ancient populations from different regions of the world.¹

Positive selection analysis -- which identifies genes that evolved rapidly under natural selection pressure -- reveals several Jomon-specific variants in genes involved in fatty acid metabolism (notably FADS1/2), thermogenesis (the UCP1 gene and associated pathways), and blood glucose regulation under cold stress. These adaptations are consistent with a lifestyle involving regular cold exposure, a diet rich in fatty fish (salmon, tuna, pelagic species), and fasting periods during harsh winters.

What distinguishes the Jomon from other cold-adapted populations such as Inuits or Yakuts from Siberia is the molecular nature of these adaptations. Inuits have developed very efficient variants in the FADS1/2 genes for metabolising large quantities of omega-3 fatty acids (their diet is dominated by marine mammals), but these variants are distinct from those found in the Jomon. The two lineages therefore "invented" different genetic solutions to solve comparable metabolic problems -- an example of evolutionary convergence at the molecular level.²

Implications for the Genetics of East Asian Populations

This study has important implications for our understanding of the genetic makeup of present-day Japanese populations. Modern Japanese are the result of mixing between Jomon descendants and Yayoi immigrant descendants, with proportions varying by region. The Okinawa (Ryukyu) populations and the Ainu of Hokkaido show a higher proportion of Jomon ancestry, while inhabitants of central Honshu's plains have predominantly Yayoi ancestry.

The discovery that some Jomon cold adaptations persist in present-day Japanese populations -- notably among the Ainu -- opens perspectives for personalised medicine and medical genetics. The FADS1/2 variants identified in the Jomon influence lipid metabolism, with potential implications for cardiovascular risk and metabolic diseases. Understanding their distribution and frequency in East Asian populations could help refine therapeutic approaches.

More broadly, this study illustrates palaeogenomicsPalaeogenomicsThe study of ancient genomes from DNA preserved in bones, teeth or sediments, to trace evolution and lineages.→' capacity to move beyond simply reconstructing human migrationsMigrationsLong-distance movements of populations; a major driver of human history (the exit from Africa, the peopling of continents, Neolithic and steppe expansions).→ to illuminate the biological mechanisms of environmental adaptation. By comparing genomes separated by millennia and thousands of kilometres, researchers can reconstruct the evolutionary pressures that shaped human populations, offering a fascinating mirror on our own biological nature.

Sources

1. Gakuhari T., Krause J. et al., "Cold adaptation pathways in Jomon hunter-gatherersHunter-gatherersA way of life based on hunting, fishing and gathering wild resources, without farming or herding; it dominated almost the whole of human history.→ distinct from other high-latitude populations", Science Advances, August 2026, vol. 12, no. 34.

2. Fumagalli M. et al., "Greenlandic Inuit show genetic signatures of diet and climateClimateThe long-term average atmospheric conditions of a region; its variations (glaciations, aridifications) shaped migrations, agriculture and the collapse of prehistoric societies.→ adaptation", Science, 349, 2015, pp. 1343-1347.

3. Gakuhari T. et al., "Ancient Jomon genome sequence analysis sheds light on migration patterns of early East Asian populations", Communications Biology, 3, 2020.

4. Kanzawa-Kiriyama H. et al., "Late Jomon male and female genome sequences from Funadomari, Hokkaido", Anthropological Science, 127, 2019, pp. 83-108.