Anthropological Science 

About: Anthropological Science is an academic journal. The journal publishes majorly in the area(s): Population & Crania. It has an ISSN identifier of 1348-8570. Over the lifetime, 645 publications have been published receiving 9066 citations.

Dual structure model for the population history of the Japanese

Abstract: この論文は, 沖縄人およびアイヌを含む日本人集団の形成史を単一の仮説で説明する二重構造モデルを提唱するものである。このモデルは次の点を想定する。すなわち, 日本列島の最初の居住者は後期旧石器時代に移動してきた東南アジア系の集団で, 縄文人はその子孫である。弥生時代になって第2の移動の波が北アジアから押し寄せたため, これら2系統の集団は列島内で徐々に混血した。この混血の過程は現在も続いており, 日本人集団の二重構造性は今もなお解消されていない。したがって身体•文化の両面にみられる日本の地域性-たとえば東西日本の差など-は, 混血または文化の混合の程度が地域によって異なるために生じたと説明することができる。またこのモデルは, 日本人の形質•文化にみられるさまざまな現象を説明するのみならず, イヌやハツカネズミなど, 人間以外の動物を対象とする研究結果にも適合する。同時に, このモデルによって日本の本土, 沖縄およびアイヌ系各集団の系統関係も矛盾なく説明することができる。

Ethogram and Ethnography of Mahale Chimpanzees

Abstract: This paper aims to compile an exhaustive list of the behavioral patterns exhibited by the chimpanzees of the Mahale Mountains National Park, Tanzania. The compilation is based on the glossary compiled by Goodall (1989), but a substantial numbers of new terms have been added. Thus, we list 316 simple anatomical terms, 81 complex anatomical terms, 37 simple functional terms, and 81 complex functional terms, in addition to 116 synonyms. The behavioral patterns are divided into eight categories on the basis of degree of universality: (1) commonly seen in both Homo and two species of Pan, (1?) commonly seen in Homo and only one species of Pan, (2) patterns common to the genus Pan but not to Homo, (3) patterns common to the chimpanzee Pan troglodytes but not the bonobo Pan paniscus, (4) patterns common to eastern (P.t. schweinfurthii) and central (Pt.troglodytes) but not western (P.t.verus) chimpanzees, (5) patterns unique to the eastern chimpanzees, P.t.schweinfurthii, (6) patterns unique to the population of Mahale, (7) patterns unique to many individuals (at least most members of an age/sex class) of M group chimpanzees, (8) patterns limited to a single (idiosyncrasy) or a few individuals of M group.It is most likely that the behavior patterns of the last common ancestor of Homo and Pan are found in Categories 1 and 1? and less likely in Categories 2 and 3.It is possible that behavior patterns belonging to Categories 5, 6 or 7 are cultures.

Individual Versus Social Learning: Evolutionary Analysis in a Fluctuating Environment

Abstract: A model for haploid asexual inheritance of social and individual learning is proposed. Animals of one genotype, individual learners (IL), behave optimally for the current environment and, except for a fixed cost due to learning errors, have the optimal fitness in that environment. Animals of the other genotype are social learners (SL) each of whom copies a random individual from the previous generation. However, the phenotype of a social learner depends on whom it copies. If it copies an IL or a correctly behaving SL, it has the “correct” phenogenotype, SLC. Otherwise, its behavior is wrong and we call its phenogenotype SLW.Different models for the environmental fluctuation produce different dynamics for the frequency of SL animals. An infinite state environment is such that when it changes, it never reverts to an earlier state. If it changes every generation, social learning can never succeed. If, however, a generation in which the environment changes is followed by l-1 generations of environmental stasis and l≥3, some fitness sets do allow the maintenance of social learning. Analogous results are shown for a randomly fluctuating environment, and for cyclic two-state environments.In a second type of model, each animal can learn individually with probability L. We examine the evolutionary stability properties of this probability in the infinite state environment. When a generation of change is followed by l-1 generations of stasis, fitness parameters can be found that produce an evolutionarily stable nonzero probability of social learning. In all of the models treated, the greater the probability of environmental change, the more difficult it is for social learning to evolve.

Molar enamel thickness and distribution patterns in extant great apes and humans: New insights based on a 3-dimensional whole crown perspective

Abstract: Molar enamel thickness is a key feature in the study of hominid evolution. Our understanding of enamel thickness and distribution patterns, however, has so far been based mostly on the limited information available from physical cross sections of the crown. In this study, the 3-dimensional (3D) whole crown enamel distribution pattern was explored in 74 extant great ape and modern human molars. Serial cross sections obtained from microfocal X-ray computed tomography were used to generate digital molar reconstructions at 50 to 80 micron voxel resolution, each crown represented by two to five million voxels. Surface data of both enamel dentine junction (EDJ) and outer enamel were extracted to derive volumetric measures, surface areas, curvilinear distances, and whole crown radial thickness maps. Three-dimensional average enamel thickness (AET) was defined as enamel volume divided by EDJ surface area. In 3D AET relative to tooth size, Homo exhibited the thickest, Gorilla the thinnest, and Pan and Pongo intermediately thick enamel. This result differs from previous claims that molar enamel of Pongo is relatively thicker than that of Pan. The discrepancy between three and two-dimensional (2D) values of AET stems from a combination of local differences in within tooth enamel distribution pattern and EDJ topography between Pan and Pongo molars. It demonstrates that 2D AET is not an appropriate substitute or estimator of whole crown AET. Examination of whole crown 3D distributions of molar enamel revealed a pattern common to all four examined species, the “functional” side of the molar having thicker enamel than the opposite side. However, some unique aspects of each species were also apparent. While the Gorilla molar has relatively thin enamel throughout its crown, Pan molars are characterized by particularly thin enamel in the occlusal fovea, and Pongo molars by an accentuation of relatively thin basal and thick occlusal enamel. Human molars are characterized by relatively thick enamel throughout the crown, with relatively large contrasts between buccal and lingual, and between mesial and distal crown portions. The ancestral condition common to the four extant species can be estimated by interpreting molar enamel distribution patterns unique to each genus as likely to be derived. We hypothesize that the last common ancestor likely had intermediately thick enamel, without particular thickening (or thinning) of enamel either occlusally or basally.

Porotic hyperostosis and cribra orbitalia : the erythropoietic response to iron-deficiency anaemia

Abstract: A recent paper by Walker et al. (2009) states that iron-deficiency anaemia can no longer be regarded as being a cause of porotic hyperostosis (PH) or cribra orbitalia (CO). It is argued here that this conclusion is not supported by the current literature on iron-deficiency anaemia and associated haematopoietic responses or consequences to this condition. Indeed, iron-deficiency anaemia is still a plausible candidate in any differential diagnosis of lesions identified as PH and/or CO.