Tracing Japonic Lineages through Matryoshka Distribution: Phylogeny, Migration, and Language Replacement in Eastern Japan

Key Points

• The study aims to examine the relationship between linguistic traits and their hierarchical structures in the context of Japanese dialects.
• Analysis of geographical distribution of Japanese dialects using the concept of matryoshka distribution.
• Re-examining the phylogenetic position of Hachijo language, considered a descendant of 8th-century Eastern Japanese.
• Investigation of language replacement mechanisms in Eastern Japan.
• Identified matryoshka distribution patterns reflecting historical linguistic evolution in Eastern Japan.
• Proposed that these patterns indicate layers of language replacement, particularly in the Ryukyuan languages.
• Confirmed the phylogenetic significance of the Hachijo language in relation to its ancestral languages.