Kazumichi Katayama

Bio: Kazumichi Katayama is an academic researcher from Kyoto University. The author has contributed to research in topics: Population & Polynesians. The author has an hindex of 8, co-authored 17 publications receiving 205 citations.

Three-dimensional ontogenetic shape changes in the human cranium during the fetal period.

Abstract: Knowledge of the pattern of human craniofacial development in the fetal period is important for understanding the mechanisms underlying the emergence of variations in human craniofacial morphology. However, the precise character of the prenatal ontogenetic development of the human cranium has yet to be fully established. This study investigates ontogenetic changes in cranial shape in the fetal period, as exhibited in Japanese fetal specimens housed at Kyoto University. A total of 31 human fetal specimens aged from approximately 8 to 42 weeks of gestation underwent helical computed tomographic scanning, and 68 landmarks were digitized on the internal and external surfaces of the extracted crania. Ontogenetic shape change was then analyzed cross-sectionally and three-dimensionally using a geometric morphometric technique. The results of the present study are generally consistent with previously reported findings. It was found that during the prenatal ontogenetic process, the growth rate of the length of the cranium is greater than that of the width and height, and the growth rate of the length of the posterior cranial base is smaller than that of the anterior cranial base. Furthermore, it was observed that the change in shape of the human viscerocranium is smaller than that of the neurocranium during the fetal period, and that concurrently the basicranium extends by approximately 8° due to the relative elevation of the basilar and lateral parts of occipital bone. These specific growth-related changes are the opposite of those reported for the postnatal period. Our findings therefore indicate that the allometric pattern of the human cranium is not a simple continuous transformation, but changes drastically from before to after birth.

Variability in stable isotope ratios in two Late-Final Jomon communities in the Tokai coastal region and its relationship with sex and ritual tooth ablation

Abstract: We analyzed stable carbon and nitrogen isotope ratios in a sample of human and nonhuman mammal bones excavated from the Yoshigo and Inariyama shell mounds of the Late-Final Jomon pe- riods in Aichi Prefecture, Japan, with a view to determining individual dietary differences. To inves- tigate possible reasons for the dietary variations identified, we related isotope ratios to sex and tooth ablation patterns. At both sites, large intra-site variations in δ 13 C and δ 15 N values were found, com- pared with other Jomon populations previously studied, suggesting higher than usual levels of dietary variability, and at both sites there was a positive correlation between δ 13 C and δ 15 N values. The diet of the Jomon people at both these sites had two main protein sources: marine (marine finfish and shell- fish) and terrestrial (C3 plants and terrestrial mammals) protein. The intra-site variability is probably explained by consumption of these resources in different proportions. Analysis of the Yoshigo shell mound data indicated that sex is one of the factors determining dietary difference. It was also found that individual differences in diet in Yoshigo males are greater than in females. This pattern was re- peated in the Inariyama shell mound data. Dietary differences were found to be related to ritual tooth ablation characteristics, particularly in males. At Inariyama, type 4I ritual tooth ablation was associated with comparatively greater dependency on terrestrial resources, while type 2C tooth ablation was as- sociated with greater dependency on marine resources. This may indicate that type 4I males engaged predominantly in hunting, and type 2C males in fishing, as a means of food acquisition. These results are possibly the earliest evidence of occupational differentiation in the Jomon people.

Mongoloid populations from the viewpoints of Gm patterns

Abstract: Gm systems provide unique markers for the study of human genetics, especially for the characterization of a population, the study of gene flow, and genetic drift by the presence of a unique haplotype or by marked differences in the frequencies of identical haplotypes. It has been shown that Gm haplotypes commonly present among Mongoloids are Gmag, Gmaxg, Gmab3st, and Gmafb1b3.

The Theory of Island Biogeography

Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

Influence of Diet On the Distribtion of Nitrogen Isotopes in Animals

Abstract: The influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition. The isotopic composition of the nitrogen in an animal reflects the nitrogen isotopic composition of its diet. The δ^(15)N values of the whole bodies of animals are usually more positive than those of their diets. Different individuals of a species raised on the same diet can have significantly different δ^(15)N values. The variability of the relationship between the δ^(15)N values of animals and their diets is greater for different species raised on the same diet than for the same species raised on different diets. Different tissues of mice are also enriched in ^(15)N relative to the diet, with the difference between the δ^(15)N values of a tissue and the diet depending on both the kind of tissue and the diet involved. The δ^(15)N values of collagen and chitin, biochemical components that are often preserved in fossil animal remains, are also related to the δ^(15)N value of the diet. The dependence of the δ^(15)N values of whole animals and their tissues and biochemical components on the δ^(15)N value of diet indicates that the isotopic composition of animal nitrogen can be used to obtain information about an animal's diet if its potential food sources had different δ^(15)N values. The nitrogen isotopic method of dietary analysis probably can be used to estimate the relative use of legumes vs non-legumes or of aquatic vs terrestrial organisms as food sources for extant and fossil animals. However, the method probably will not be applicable in those modern ecosystems in which the use of chemical fertilizers has influenced the distribution of nitrogen isotopes in food sources. The isotopic method of dietary analysis was used to reconstruct changes in the diet of the human population that occupied the Tehuacan Valley of Mexico over a 7000 yr span. Variations in the δ^(15)C and δ^(15)N values of bone collagen suggest that C_4 and/or CAM plants (presumably mostly corn) and legumes (presumably mostly beans) were introduced into the diet much earlier than suggested by conventional archaeological analysis.

Size, shape, and form: concepts of allometry in geometric morphometrics

Abstract: Allometry refers to the size-related changes of morphological traits and remains an essential concept for the study of evolution and development. This review is the first systematic comparison of allometric methods in the context of geometric morphometrics that considers the structure of morphological spaces and their implications for characterizing allometry and performing size correction. The distinction of two main schools of thought is useful for understanding the differences and relationships between alternative methods for studying allometry. The Gould–Mosimann school defines allometry as the covariation of shape with size. This concept of allometry is implemented in geometric morphometrics through the multivariate regression of shape variables on a measure of size. In the Huxley–Jolicoeur school, allometry is the covariation among morphological features that all contain size information. In this framework, allometric trajectories are characterized by the first principal component, which is a line of best fit to the data points. In geometric morphometrics, this concept is implemented in analyses using either Procrustes form space or conformation space (the latter also known as size-and-shape space). Whereas these spaces differ substantially in their global structure, there are also close connections in their localized geometry. For the model of small isotropic variation of landmark positions, they are equivalent up to scaling. The methods differ in their emphasis and thus provide investigators with flexible tools to address specific questions concerning evolution and development, but all frameworks are logically compatible with each other and therefore unlikely to yield contradictory results.

The Settlement of the Americas: A Comparison of the Linguistic, Dental, and Genetic Evidence

Abstract: The classification of the indigenous languages of the Americas by Greenberg distinguishes three stocks, Amerind, Na-Dene, and Aleut-Eskimo. The first of these covers almost all of the New World. The second consists of Na-Dene as defined by Sapir and, outside of recent. Athapaskan extensions in California and the American Southwest, is found in southern Alaska and northwestern Canada. The third, Aleut-Eskimo, is the easternmost branch of the Eurasiatic language family located in northern Asia and Europe. These three linguistic stocks are found to agree well with the three dental groups proposed by Turner and the genetic divisions of the New World population advanced by Zegura. The three groups are hypothesized as representing the settlement of the New World by successive migrations from Asia. The earliest is in all probability the Amerind; the relative priority of Na-Dene to Aleut-Eskimo is less certain. The evidence regarding the absolute chronology of these proposed migrations is discussed.

The Settlement of the Americas: A Comparison of the Linguistic, Dental, and Genetic Evidence [and Comments and Reply]

Abstract: The classification of the indigenous languages of the Americas by Greenberg distinguishes three stocks, Amerind, Na-Dene, and Aleut-Eskimo. The first of these covers almost all of the New World. The second consists of Na-Dene as defined by Sapir and, outside of recent. Athapaskan extensions in California and the American Southwest, is found in southern Alaska and northwestern Canada. The third, Aleut-Eskimo, is the easternmost branch of the Eurasiatic language family located in northern Asia and Europe. These three linguistic stocks are found to agree well with the three dental groups proposed by Turner and the genetic divisions of the New World population advanced by Zegura. The three groups are hypothesized as representing the settlement of the New World by successive migrations from Asia. The earliest is in all probability the Amerind; the relative priority of Na-Dene to Aleut-Eskimo is less certain. The evidence regarding the absolute chronology of these proposed migrations is discussed.