Biology subjects

Kondo, O.

Publications and source records attributed to Kondo, O..

5 recordsLinked to original sources

bioRxiv2026

DeMoDa: A global open access database for comparative research in human dental morphological variation

Human dental morphology is diverse and varies both within and between populations worldwide. Common variants include different numbers of cusps and roots, as well as different configurations in the fissures, ridges, and grooves on tooth crowns. Because teeth preserve well in taphonomic contexts and retain strong genetic signatures in their morphology, researchers across disciplines use dental form for research ranging from population affinity identification in forensic cases to the reconstruction of population history in archaeological and paleontological studies, and to explore the genetic underpinnings of dental development. However, these analyses are limited, as no publicly available comprehensive database of human dental morphological variation currently exists. Data are typically shared only within professional networks, excluding scientists outside those circles. Information is dispersed across repositories and the supplementary materials that accompany peer-reviewed publications, creating a fragmented and difficult-to-navigate data landscape. Although numberous dental anthropologists devoted their careers to collecting extensive datasets from thousands of individuals worldwide, their data have not yet been published in raw form nor made compatible. Here, we introduce the Dental Morphological Database (DeMoDa), an open access repository comprising 246 dental traits for 17,308 individuals across 32 major geographic regions worldwide spanning the past several thousand years. These data are from the legacy datasets of Turner, Hanihara, Scott, and Irish. Because these researchers used different scoring systems, we developed a scoring system with two steps that enables the three most-common scoring systems to be combined. We provide two versions of the data that correspond to these two steps: one with more nuanced trait scores at the cost of a smaller sample size, and another with less nuanced trait scores but broader sample coverage. We discuss the implications of publishing these legacy data and outline our decision-making process that guided their release in accordance with both the FAIR and CARE principles of open science.

evolutionary biology↗

bioRxiv2025

High-Coverage Jomon Genomes Provide Insights into Population Structure and Genetic Traits of Ancient Japanese Hunter-Gatherers

We analyzed eight high-coverage Jomon genomes spanning 9,000-2,800 years ago across the Japanese archipelago. Population genomic analyses revealed substantial genetic homogeneity across time and space reflecting post-glacial isolation, yet temporal stratification emerged: Initial Jomon (Iyai) individuals formed the earliest branch with weaker affinities to present-day Japanese. Using genomes from Todoroki and Chidorikubo sites, we estimated Jomon ancestry in mainland Japanese at [~]20%, substantially higher than previous estimates ([~]13%). Polygenic score analyses, based on the direct analysis of Jomon genomes, provided the genetic evidence for their phenotypic predispositions, including elevated BMI and metabolic trait scores, reduced immune-related scores, and larger cardiac dimensions, patterns consistent with hunter-gatherer adaptations. These ancestral genetic influences, including elevated risks for obesity and dyslipidemia, persist in present-day Japanese. Our findings demonstrate that Jomon populations maintained genetic continuity despite ecological diversity, while their greater-than-expected contribution to present-day Japanese reshapes population history models and reveals how ancient adaptations continue influencing contemporary disease susceptibility.

genomics↗

bioRxiv2025

Postnatal interaction of size and shape in the human endocranium and brain structures

The uniqueness of human brain growth and development has been considered promising to understand the advanced cognitive ability of humans. Compared with that of chimpanzees, the human endocranium undergoes several characteristic shape changes immediately after birth, which has been termed "endocranial globularization." However, how the brain structures and surrounding neurocranium interact with each other during early development in the context of brain-neurocranium integration remains to be investigated. We observed shape changes in the human brain and endocranium during postnatal development using magnetic resonance imaging, and analyzed spatial constraints and interactions among subdivisions of the brain influencing endocranial morphology. Our results suggest that during postnatal development, the relative size changes of supratentorial and infratentorial regions and the cranial base largely constrain brain and endocranium shape. Specifically, a disproportionate increase in the size of the cerebellum relative to the cranial base affects infratentorial spatial packing constraints in neonates, causing inferoposterior expansion of the posterior cranial fossa and coronal reorientation of the petrous bone without lateral opening of the tentorium cerebelli. The dramatic size increase of the cerebellum relative to the cranial base immediately after birth is inferred to be characteristic of human development, which corresponds to previously observed bony shape changes.

evolutionary biology↗

bioRxiv2024

High-coverage genome sequencing of Yayoi and Jomon individuals shed light on prehistoric human population history in East Eurasian

The migration of prehistoric humans led to intriguing interactions and changes in cultural and genetic heritage. In Eurasia, prehistoric migration and population replacement have affected present-day humans. The available high-quality genetic evidence for prehistoric migration in eastern Eurasia, particularly in the Far East, is still limited. We succeeded in obtaining low-contaminant, high-coverage genomes from middle-Yayoi (>46-fold coverage) and Initial Jomon (>67-fold coverage) individuals from mainland Japan. This study demonstrated that the Yayoi individual exhibited a genetic profile distinct from that of the indigenous Jomon population of the Japanese archipelago, suggesting that Yayoi ancestry was connected to the peopling of the Eurasian continent. Our high-coverage genome provides interesting insights into the evolution of copy number polymorphisms related to the dietary styles of ancient Japanese people. The copy number estimates of the amylase gene for the Yayoi individual were comparable to those of present-day East Asians who have diets high in starch. This suggests that the population in the middle Yayoi period may have already adapted to high-starch diets, which may have been related to paddy rice agriculture introduced from the continent. Furthermore, the individual from the initial Jomon period showed high amylase copy numbers comparable to those from modern East Eurasia, including modern Japanese. This suggests that some Jomon people may have consumed a high-starch diet then. The high-coverage whole-genome sequence also revealed differences in the demographic backgrounds of the two ancestral populations during the Yayoi and Jomon periods. Our results shed light on the prehistorical events and origins of related migrations from Eurasia at that time and their genetic background, cultural transformations, and links to modern Japanese people.

genomics↗

bioRxiv2019

Jomon genome sheds light on East Asian population history

Anatomical modern humans reached East Asia by >40,000 years ago (kya). However, key questions still remain elusive with regard to the route(s) and the number of wave(s) in the dispersal into East Eurasia. Ancient genomes at the edge of East Eurasia may shed light on the detail picture of peopling to East Eurasia. Here, we analyze the whole-genome sequence of a 2.5 kya individual (IK002) characterized with a typical Jomon culture that started in the Japanese archipelago >16 kya. The phylogenetic analyses support multiple waves of migration, with IK002 forming a lineage basal to the rest of the ancient/present-day East Eurasians examined, likely to represent some of the earliest-wave migrants who went north toward East Asia from Southeast Asia. Furthermore, IK002 has the extra genetic affinity with the indigenous Taiwan aborigines, which may support a coastal route of the Jomon-ancestry migration from Southeast Asia to the Japanese archipelago. This study highlight the power of ancient genomics with the isolated population to provide new insights into complex history in East Eurasia.

genomics↗