Echoes of Early Jōmon Honshu

A cool, salt-scented dawn over the islands: the Early Jōmon of Honshu emerged as intensifying coastal economies and refined pottery traditions reshaped lives after the last Ice Age. Archaeological data indicates that by the Early Jōmon (broadly c. 5000–3500 BCE) communities were exploiting rich littoral resources and establishing recurring shell midden sites. The five sampled individuals date to 4339–3528 BCE and were recovered from two well-known shell midden contexts: Funagura Shell Midden near Kurashiki and the Odake Shell Midden in the Kureha Hills of Toyama Prefecture. These sites capture a landscape of bays, estuaries, and forested hills where people harvested shellfish, fish, and seasonally available plants.

Material culture — cord-marked pottery, ground stone tools, and evidence of repeated hearths — indicates a durable, place-based foraging way of life rather than full sedentism or agricultural dependence. Limited evidence suggests local continuity from Late Pleistocene populations in the archipelago, but the exact population dynamics (long-term in situ development versus small-scale influxes) remain debated. Genetic data from these five individuals provide glimpses into maternal lineages present on Honshu during the Early Jōmon, offering an additional line of evidence to test archaeological models of continuity and contact. Given the small sample size, any larger inferences about origins across the archipelago must remain tentative.

The genetic signal from these five Early Jōmon individuals is modest but evocative. Mitochondrial DNA (mtDNA) recovered includes haplogroups M (two individuals), N (two individuals), and M7a (one individual). These maternal lineages are deep branches of East Eurasian mtDNA diversity. Haplogroup M and its sublineages are widespread in East and Southeast Asia and are common in ancient and modern populations of the Japanese archipelago; M7a in particular has been observed in other Jōmon-associated remains and in some present-day Japanese populations, suggesting potential maternal continuity. Haplogroup N represents a broad lineage that also occurs across Eurasia and East Asia; its presence here underscores the heterogeneous maternal pool in Early Jōmon groups.

No Y-chromosome (paternal) haplogroups are reported for these samples, so paternal lineage structure remains unknown for this data set. Important caveats apply: the total sample count is five (<10), so population-level conclusions are preliminary. Ancient genomics from larger Jōmon series often indicate that Jōmon individuals carry a distinctive genetic component—deeply rooted in East Asian prehistory—that contributed to later populations in the archipelago, including partial ancestry in modern Japanese, Ainu, and Ryukyuan groups. The current mtDNA patterns support a picture of long-term maternal line continuity in some locales, but without broader autosomal and Y-DNA data from greater numbers of individuals, models of gene flow, population structure, and regional heterogeneity remain tentative. Future sampling and whole-genome analyses will be necessary to resolve these patterns with confidence.