The current concept of the molecular clock is primarily based on the assumption that there is a constant rate of molecular substitution in all mammals. The calibration of the albumin clock of SARICH & CRONIN (1976) set 100 albumin immunological distance units (IDU) between two taxa equal to a most probable divergence time of 60 m, y. ago, based primarily on the early primate data. On this scale the marsupial-placental albumin immunological distance is about 210 units, corresponding to a period about 125m.y. ago, and the antiquity of the basic placental adaptive radiation is set at 90-100 m.y. ago. These values are will in accord with the paleontological data. According to SARICH & CRONIN, the catarrhine-platyrrhine divergence must have occurred about half as long ago as the beginning of of the prosimian-anthropoid split (70m.y. ago), that is, about 35m. y. ago. The conclusion that the catarrhine-platyrrhine divergence occurred about 35m. y. ago is in concordance with the paleontological records. However, the data of 70m. y. ago for the prosimian-anthropoid split does not agree with the initial assumption of a divergence date of 60m.y. ago given the substitution rate as 0.6m. y. per 1 IDU. Moreover, the paleontological records suggest that their divergence date is 50m.y. ago. These data do not support the assumption that there is a constant rate of molecular substitution. FITCH & LANGLEY (1976) described the relationship between nucleotide substitution and the divergence dates of mammals. The linear relationship between time elapsed and nucleotide substitution is beautifully observed, but all the primate pairs fall significantly below the line. From these results, FITCH & LANGLEY concluded that primates show a lower evolutionary rate of nucleotide substitution. However, they did not show the magnitude of the slowing down of its rate in primates. To correct the observed divergence of the prime data, the primate pairs were re-plotted according to the following method: the numbers for nucleotide substitution of each pair are unchanged, but the paleontologically estimated dates of divergence of each pair are shortened to one-half of the elapsed time estimates used by FITCH & LANGLEY. These new points are beautifully arranged closed to the original correlation line. Most of the new points are still below the line, but the older divergent pair (cercopithecids-pongids) is replotted above the line. This means that the divergence dates predicted by using the cor relation line represent less than half the elapsed time estimated paleontologically, except for the elder divergent pair. This evidence may indicate that the magnitude of the discrepancy between the paleontologically estimated dates and the dates predicted by the molecular clock depends on relative age of divergence among anthropoids: the more recent divergence date, the greater the magnitude of the discrepancy.

View full abstract

Cardiac output (Q) was measured by the CO₂ rebreathing method in 10 boys and 9 girls. They performed cycle ergometer exercises at 300 and 450kgm/min in ambient temperatures kept at 20, 30, and 40°C. For a given oxygen uptake (Vo₂), stroke volume (SV) tended to be reduced and heart rate (HR) increased in a 40°C environment in both sexes. Accordingly, Q at 40°C was maintained at a level similar to that in cooler conditions. A lower HR and a higher SV at a given Vo₂ were shown in boys than in girls. The regression equation of Q on Vo₂ in boys was found to be similar to that in girls. The values of Q in relation to Vo₂ in the children studied were compared with those in children and adults who had been previously studied. The children in the present study were found to have a Q response that represented roughly an average of those of children described in the literature cited, and to have a lower Q as compared with most adults.

View full abstract

This study was attempted to make new equation for predicting body composition of Japanese young females at any levels of habitual physical activity. Female athletes (n=51) and non-athletes (n=23) were measured for body composition using 16 anthropometric dimensions and hydrostatic weighing.
The analysis of covariance confirmed that the relationship between body density and skinfold measurements was significantly different between the groups. On the other hand, the relationship between total body volume and body weight or girth measurements was similar between the groups. Therefore, the prediction equation of total body volume was derived from body weight and girth measurements. The equation for total body volume was calculated as follows ; TBV=0.8912BW+0.0702CG+0.0578WG+0.0957TG-10.957 (R=0.997, S. E. E.=0.455) where TBV, BW, CG, WG and TG were total body volume in liter, body weight in kg, chest, waist and thigh girth in cm, respectively. The equation for %Fat was also calculated by substituting the equation for TBV into BROZEK et al. formula for %Fat as follows ;%Fat=(32.08CG+26.41WG+43.73TG-6.92BW-5007.35)/BW
(R=0.710, SEE=3.12).

View full abstract

Angles of hindlimb joints in the extreme flexion and extension caused passively under anaesthesia were examined in 8 male and 8 female Japanese macaques. A hypothetical complete flexion and extension of the joints was regarded as 0° and 180°, respectively. Hip joint angle in maximum extension was 138±7.9° (mean±SD), without a significant sex difference. The anterior thigh touched the belly at a hip joint angle of about 50°. Knee joint angle in maximum extension decreased from 162.9±9.9° to 153.8±10.2°, corresponding to a reduction of the hip joint angle from 125° to 55°, i. e. from an extended position to a flexed one. The heel touched the posterior thigh at a knee joint angle of 30°. While a knee joint flexion allowed a complete plantar flexion and dorsiflexion of the ankle joint, extension of the former seriously limited a dorsiflexion of the latter. Obtained results were briefly discussed in terms of the influence of double-jointed muscles and the joint motion during walking.

View full abstract

In this paper several dental characteristics of the Micronesians were compared with those of three other populations-Pashtuns, Hawaiians and Japanese-the data of which were obtained by one of the present authors, T. SAKAI. The materials used in this study were 194 skulls housed in the Bishop Museum, Honolulu. The Hawaiian samples used for comparison were obtained from the skulls in the same museum. The Japanese and Pashtun samples were the plaster casts obtained from those living in Japan and Afghanistan. The results are briefly summarized as follows:
1. Fifteen non-metric crown characters were observed and comparisons between Micronesians and the other populations were carried out on the basis of their frequency distributions. According to this comparative study, the frequency distributions of the Mongoloid dental complex and its related dental characteristics in the Micronesians are generally higher than in the Pashtun, lower than in the Japanese, and similar to the Hawaiians.
2. The incidence of reduced molars in the Micronesians and the Hawaiians was clearly less than in the other two populations.
3. Distance coefficients devised by SMITH were used as a tool for the comparison between these populations. Micronesians are biologically similar to Hawaiians and dissimillar to Pashtuns. The distance between Micronesians and Japanese is small. Based on SMITH'S distance, the following clusters seem to be distinguished: Micronesian-Hawaiian cluster, Japanese cluster and Pashtun cluster.

View full abstract

Changes in pulmonary diffusing capacity for carbon monoxide (D_L), the diffusing capacity of the pulmonary capillary membrane (D_M) and pulmonary capillary blood volume (V_C) at rest were examined in eight adult subjects of both sexes by the breath-holding method under different posture and temperature conditions; i. e., in a supine position and a head-up position (45°) by the use of a tilting bed at three ambient temperatures of 15, 25 and 35°C. Under all these conditions, D_L was closely related to changes in V_C. Posture significantly affected D_L and V_C in both males and females, the degree of difference due to each posture in males being similar to that in females. Although the influence of temperature on D_L and V_C was significant in males, it was somewhat vague in females. The following causes of this phenomenon were suggested: the range of variation in the pulmonary arterial pressure due to thermal stimulation is narrow and the size of the lung is smaller in females than in males. The relation of D_L to wide-spread changes in V_C in both sexes showed the form of a curve, probably because the increase in V_C mainly reflects the process of transformation of the pulmonary capillary from recruitment to dilation.

View full abstract

Histochemical examinations of muscle fiber types by Sudan black B staining were made on m. biceps brachii of male and female white-handed gibbon (Hylobates lar). Three types of muscle fibers could be discriminated in terms of the reaction to the pigment and the cellular diameter: red muscle fiber (type I) with a positive reaction and a small diameter; white muscle fiber (type II) with a weak reaction and a large diameter; intermediate muscle fiber (type III) with an intermediate reaction and diameter. Of 4648 muscle fiber cells, in average of male and female, scanned in the cross-section, red muscle fibers accounted for 44.1%, white muscle fibers 28.3%, and intermediate muscle fibers 27.6%, respectively. White muscle fibers were clearly localized in the external layers of both heads of m. biceps brachii. In contrast, red muscle fibers were more evenly distributed throughout the muscle though moderately localized in the regions adjacent to the sulcus bicipitalis medialis. Intermediate muscle fibers showed no specific localization at all. These results suggest that m. biceps brachii of the gibbon, an acrobatic armswinger, is inclined to be a red muscle that is fatigue-resisting rather than power-generating.

View full abstract

In the present study, the skeletal remain of an Ainu showing a chronic inflammative lesion with remarkable osteolytic and destructive changes in the sacral base was compared morphologically in detail with a dry bone specimen of an autopsy case of a modern Japanese who died of tuberculosis. The bone lesion of the former case could be diagnosed as bone tuberculosis with certainty due to the similarity with the latter.
In interpretation on pathological changes appearing in the ancient human skeletal remains, the application of bone-specimen diagnosed by means of modern clinicopathological procedures is important and useful for palaeopathological diagnosis.

View full abstract