Zeitschrift fur Morphologie und Anthropologie最新文献

The dimensions of the distal leg muscles in ten different primate species were examined in order to determine whether locomotor specialization is reflected in the fibre and tendon lengths of these muscles. For comparative purposes a non-primate was also included in the study. The locomotor specializations displayed by the investigated species were leaping, quadrupedal walking or running on the ground, quadrupedal climbing, and brachiation. After removal of the muscles and measurement of their free tendon lengths, fibres were isolated from several locations in the muscle and their lengths measured. Statistical tests revealed some differences between the species in fibre and tendon lengths. These did not show a consistent correlation with the locomotor specialization. It was concluded that every primate species has the potential to perform a variety of movements and to specialize in any locomotor mode.

On the basis of theoretical biomechanics and of experiments, we investigated the mechanical requirements to which the body of a bipedally walking primate is subject, and the possibilities to meet these requirements with a minimum amount of energy. The least energy-consuming adaptation is clearly a body shape favourable for the preferred locomotion. Some characteristics of human body shape, in particular its proportions, could be identified as advantageous for fulfilling obvious biological roles or mechanical necessities. The characteristic length and the extended position of human hindlimbs make walking faster without additional input of energy. Mass distribution on the hindlimbs reduces the energy necessary for accelerating the swing limb after liftoff and for decelerating the swing limb before the heelstrike. Length and mass distribution in the forelimb gives it a pendulum length comparable to that of the hindlimb, so that both extremities swing at the same frequency. This swinging of the forelimbs counters in part the movements exerted by the moved hindlimbs on the trunk. The elongate and slim shape of the trunk provides great mass moments of inertia and that means stability against being flexed ventrally and dorsally by the forward and rearward movements of the heavy and long hindlimbs. Shoulder breadth in combination with the shallow shape of the thorax yield higher mass moments of inertia against the rotation of the trunk about a vertical axis than a cylindrical trunk shape. Further elongation of the hindlimbs is limited by the energy necessary for acceleration and deceleration, as well as for lifting them during the swing phase. In addition, the reaction forces exerted by the hindlimbs would expose the trunk to undue excursions if the proportions trunk length/limb length or trunk mass/limb mass would decrease. The above-noted kinetic requirements are partly in line, partly in conflict with the requirements of statics.

112 Iranian population samples with a total of 600954 individuals are analyzed concerning the ethnic variability of ABO allele frequencies. The genetic heterogeneity within and between these population samples is considerable. This heterogeneity is discussed with regard to the ethnohistory of Iran. The most striking ABO allele frequencies are observed in Assyrians, Armenians and Zoroastrians, which differ extremely from that of all the other hitherto studied ethnic groups of Iran. Obviously varying ABO allele frequencies are seen also in Yazdis as well as in Turkomans and Arabs living in Iran. And finally the Iranian Jews reveal clear frequency differences in comparison with all the other Iranian population groups. It can be assumed that the specific ABO allele frequencies found in the above mentioned ethnic groups are connected with their different geographical origin as well as with their marked endogamy.

Tendons that stretch elastically and recoil, as the forces on them rise and fall, can save energy in running by enabling the animal to make do with shorter or slower muscle fascicles, that can generate force more economically. Non-human primates have rather long fascicles and thick tendons in their distal leg muscles and so seem poorly adapted to save energy in this way. Additional savings are made possible by the elastic compliance of ligaments in the foot. Though tendon and ligament compliance tend to save energy, the compliance of branches tends to increase the energy cost of arboreal locomotion.

The jump is always used for locomotion. For its execution in arboreal and terrestrial biotopes the requirements are of somewhat different nature. In an arboreal biotope the jump is characterized by a rapid progression through discontinuous substrates and the ability to take off from a small area and a secure landing on a spot. This requires well coordinated movements in all phases of the jump. On the ground, the jump is less frequent and often used for crossing obstacles or gaps. In primates both variants can be observed. In order to relate the details of locomotor behaviour to a certain environment, the biomechanics of jumping are analyzed in five primate species: The three mainly arboreal prosimian species Galago moholi, the smallest and most specialized leaper of all, Galago garnettii, a medium-sized bushbaby with some capacities for jumping, and Lemur catta also with some abilities to jump. The two simian species, Macaca fuscata and Homo sapiens, are usually terrestrial and have good jumping capacities, although not in terms of quantity. The investigation is based on high-speed motion analyses (100-500 frames/second) and the synchronized records of a force-plate from which all subjects had to jump off. On the basis of the results two kinds of jumping can be distinguished: standing and running jumps. The three prosimian species perform standing jumps. Dorsiflexion of their tails compensates ventrally oriented rotational moments of the trunk during body extension at take-off. The upward arm swing yields an overall increase in take-off velocity without additional muscular force exerted by the legs. The main difference among the species are the high relative forces in the small Galago moholi (up to 13 times body weight) as compared to the larger G. garnettii (8.5 times body weight) and the even larger Lemur catta (4.5 times body weight). In Homo sapiens the standing jump is characterized by an extensive arm swing backward, which is then followed by a forward and upward movement. The velocity at take-off is much smaller if compared to the prosimians. The running jump in Macaca fuscata is always preceded by at least one gallop cycle. The body assumes a ball shape at the beginning of the actual take-off. This is advantageous for rotating the body into a position in which the trunk axis is in line with the direction of movement. The tail of the Japanese macaque is too short to compensate the trunk's lift exerted on the hip region by the extending hindlimbs.(ABSTRACT TRUNCATED AT 400 WORDS)

The morphological differences between the limb bones of two Adapis species from two localities in Southern France are analyzed for their functional significance. The study focuses on the distal humerus, proximal femur, astragalus and calcaneum. The Escamps species Adapis aff. betillei shows more extreme flexion at the elbow, lateral mobility at the hip, and more rotation at the calcaneocuboid joint than in the other species. The species from Rosières 2 A. cf. parisiensis shows increased emphasis on parasagittal movements, restrictions of lateral mobility in the hindlimb, enhanced capacity for rapid flexion and powerful extension of the thigh, and powerful rapid foot extension. The Rosières species probably engaged in more frequent branch walking and running, and the Escamps species probably included more climbing in its locomotor repertoire. In the general Adapis genus morphology, the large tuber calcanei, short astragalus, and the presence of a calcaneal "pressure facet" are similarities shared with living cercopithecids. Along with other characters, these suggest that horizontal running was possibly an important means of locomotion in the Adapis and adapine morphotypes, and may even indicate a degree of terrestraility. Contrary to the most common view, the euprimate morphotype was probably not a specialized leaper.

The aim of this review is to bring together data that link tooth morphology with tooth function and tooth growth: We aim to show how the microanatomy of hominoid teeth is providing evidence about rates of tooth growth that are likely to be a consequence of both masticatory strategy and social behaviour. First, we present data about incisor and molar tooth wear in wild short chimpanzees that demonstrate how crown heights are likely to be related to relative tooth use in a broad sense. Following this we review recent studies that describe the microanatomy of hominoid tooth enamel and show how these studies are providing evidence about tooth crown formation times in hominoids, as well as improving estimates for the age at death of certain juvenile fossil hominids. Next, we outline what is known about the mechanisms of tooth growth in the sexually dimorphic canine teeth of chimpanzees and compare these patterns of growth with tooth growth patterns in the canines of three fossil hominids from Laetoli, Tanzania. Finally, we discuss how selection pressures that operate to increase or reduce the size of anterior teeth interact with jaw size. We argue that the space available to grow developing teeth in the mandibles of juvenile hominoids is determined by the growth patterns of the mandibles, which in turn reflect masticatory strategy. The consequences of selection pressure to grow large or small anterior teeth are likely to be reflected in the times at which these teeth are able to emerge into occlusion.

Leaping primates often assume a horizontal position while airborne. When the limbs are spread out in such maneuvers, skin folds between the upper limbs and the trunk are exposed. This has led to the assumption that the animals make use of aerodynamic forces for either gliding, steering, or braking before the landing. In terms of physics, aerodynamic lift or aerodynamic drag can cause the described effects. As coefficients of lift and drag are unknown for flying primates, we have calculated those values that give the animals either a 5% gain or loss in leaping distance. These turn out to be in the range of values for cylinder-shaped "blunt" (unstreamlined) bodies. A significant influence of aerodynamic forces on the flight path can therefore be assumed. The smaller-bodied species (e.g., galagos) are more strongly influenced by their great surface areas. Although frontal areas scale positively allometrically with respect to body mass, air speed gains importance in the larger-bodied species (e.g., sifakas). They cover absolutely greater distances and have the higher takeoff velocities. The actual importance of lift and drag cannot be derived from our theoretical calculations but must be determined experimentally.

We describe here the mid-facial region of a skull of anatomically modern Homo sapiens (FAI 3/2/1) that exhibits upwardly divergent nasal bones. In previous literature, that pattern has been described as a diagnostic character state for the robust early hominid taxon Paranthropus. This specimen supports our viewpoint that nasal region morphology varies extensively within and between living hominoid primate taxa, in patterns that provide a basis for understanding how microevolutionary variation serves as the basis for macroevolutionary transformations.