Human Evolution 

About: Human Evolution is an academic journal. The journal publishes majorly in the area(s): Population & Homo erectus. It has an ISSN identifier of 0393-9375. Over the lifetime, 669 publications have been published receiving 10999 citations.

Skeletal age determination based on the os pubis: A comparison of the Acsádi-Nemeskéri and Suchey-Brooks methods

Abstract: After reviewing various systems of age determination based on analysis of the pubic bone, the discussion concentrates on the collection and preparation of an extensive autopsy sample (n=1225) of pubic bones from modern individuals with legal documentation of age at death (death and/or birth certificates). TheSuchey-Brooks method derived from this sample is described. TheAcsadi-Nemeskeri system is evaluated in terms of the documented collection and it is seen that their five stage method focuses only on the early and late morphological changes. The intermediate stages, in which the ventral rampart is in process of completion, are not described. Their suggested age ranges do not correspond with the documented modern sample. Based on these limitations of theAcsadi-Nemeskeri method, applications of theSuchey-Brooks system are discussed.

Observational learning of tool-use by young chimpanzees

Abstract: In the current study two groups of young chimpanzees (4–6 and 8–9 years old) were given a T-bar and a food item that could only be reached by using the T-bar. Experimental subjects were given the opportunity to observe an adult using the stick as a tool to obtain the food; control subjects were exposed to the adult but were given no demonstration. Subjects in the older group did not learn to use the tool. Subjects in the younger group who were exposed to the demonstrator learned to use the stick as a tool much more readily than those who were not. None of the subjects demonstrated an ability to imitatively copy the demonstrator's precise behavioral strategies. More than simple stimulus enhancement was involved, however, since both groups manipulated the T-bar, but only experimental subjects used it in its function as a tool. Our findings complement naturalistic observations in suggesting that chimpanzee tool-use is in some sense «culturally transmitted» — though perhaps not in the same sense as social-conventional behaviors for which precise copying of conspecifics is crucial.

Estimation of stature from long bones utilizing the line of organic correlation

Abstract: Estimation of stature from skeletal measurements is of great interest in some studies, e.g. in forensic anthropology, where victims have to be identified. A problem occurring in practice is that the individual whose stature has to be assessed is in general from an unknown population. Alternatives to ordinary least squares regression are discussed. Application of available information about stature/long bone proportions leads to a general proposal called thethe weighted line of organic correlation, which is fitted to a wide range of populations. The effects of sex and race upon this line are practically negligible. These properties makes it suitable for use not only for forensic purposes, but also for the estimation of stature based on skeletons or skeletal populations from the past.

Ontogenetic approaches to sexual dimorphism in anthropoids

Abstract: Studies of sexual dimorphism have traditionally focused on the static differences in size and shape between adult males and females. In this paper, I suggest that an investigation of the ontogenetic bases of sexual dimorphism can provide new insights and information unobtainable from studies concerned only with adult endpoints. While growth is often viewed as simply the developmental pathway utilized to attain final adult size and shape, we must recognize that it is the entire pattern of sex-differentiated growth, and not merely the adult endpoints, which is adaptive and the target of natural selection. The importance of an ontogenetic approach to the analysis of sexual dimorphism is also demonstrated by the fact that a given morphologicalresult (e.g., a certain degree of adult weight dimorphism) may be attained by very different developmentalprocesses, signalling selection for quite different factors. The need to analyze the ontogenetic bases of sexual dimorphism in size and shape has recently been recognized by Jarman, in his study of dimorphism in large terrestrial herbivores. Here I combine aspects of Jarman’s approach with those of allometry and heterochrony in an analysis of sexual dimorphism in selected anthropoid primates. It is demonstrated that although all dimorphic anthropoids appear to be characterized by somebimaturism, the degree varies significantly. Marked weight dimorphism in certain species is primarily produced by an increased differentiation of female and male growthrates, while in other species the primary change involves differences in thetime or duration of growth between the sexes. These variations are illustrated with anthropoid genera such asMiopithecus, Cercopithecus, Erythrocebus, Macaca, Papio, Pan, andGorilla. It is suggested that additional ontogenetic investigations of other anthropoids will help clarify some of the socioecological bases of this variation in the ways of attaining an adult dimorphic state. This will contribute to our understanding of the complex factors underlying and producing sexual dimorphism in primates and other mammals.