Rapid brachycephalization observed in 20th century Japan ceased with the generation born in the mid-1960s, when debrachycephalization started. If the onset of debrachycephalization is caused by environmental factors, it is likely that those environmental changes occur by 1 year of age, when the head length (HL) and head breadth (HB) reach about 80–90% of the adult size. An increase in the rate of deliveries performed by Caesarian section (C-section) is one possible factor for the start of this debrachycephalization. In order to evaluate the effects of C-section on the adult cephalic index (CI), information on the type of delivery was obtained through interviews, and HL and HB were measured for 122 female students born between 1990–1998. The effects of vacuum extraction (VE) were examined for females born by vaginal delivery using one-way ANOVA. No significant difference was observed in HL, HB, and CI between groups born with VE, without VE, and with no information. Therefore, data from the three groups were combined and used for further analyses. Females born by vaginal delivery (N = 98) and those born by the C-section (N = 21) were compared using t-test, and no significant between-group difference was observed in HL, HB, and CI. These results support previous findings that reject the long-term effect of head molding during vaginal delivery. These results also reject the hypothesis that changes in delivery type caused a reversal of secular change in cephalic index.

A number of studies have reported increased body size of Japanese adolescents after World War II. However, in recent decades, to the best of our knowledge, there has been no secular change in height due to exhaustion of the genetic potential for change. The present study aims to clarify secular changes in body size in Japanese adolescents aged 17 years using data from the Statistical Report of the School Health Survey and applying a body proportion chart method. This method simultaneously examined secular changes in height, sitting height, leg length and upper-lower length ratio, and revealed that the linear proportions of contemporary adolescents are changing with a trend toward increasing sitting height and decreasing leg length relative to sitting height, though overall height increase has stopped. This secular change in sitting height can be attributed to an increase in the population with a high sitting height as an inherited trait. If the delivery rate of women with a long torso is higher owing to their morphological advantage, the average sitting height of the next generation will increase. Considering that the linear proportions of Japanese adolescents are still changing, the annual measurement of sitting height as part of the school health survey should be maintained.

The Amud Cave site in the Upper Galilee, Levant, the east coast of the Mediterranean, was found as a Middle Palaeolithic site in 1960 by Hitoshi Watanabe, member of the Tokyo University Scientific Expedition to Western Asia (TUSEWA), during his intensive general survey to find a new Middle Palaeolithic site. The TUSEWA team, directed by Hisashi Suzuki, excavated the cave site twice in 1961 and 1964 and found out several Neanderthal remains, including the Amud I skeleton, in association with a large quantity of stone artifacts of Middle Palaeolithic assemblage and a lot of animal bone fragments. The Amud Cave site situates a key place of the human’s out of Africa into Eurasia. The Amud human remains and their site exhibit rich information on the human evolution especially the relationship between the archaic Neanderthals and the anatomically modern humans. The cave was excavated thirty years later in 1991–1994 by the Israeli team and many individuals of Neanderthals were unearthed. The new excavation was feasible because the TUSEWA team has purposely left enough sediment for the future studies. Two series of excavation were, although separated thirty years of time distance and conducted by different study teams, continuously adjusted in each other, because the TUSEWA team strictly decided and reported the grid system and the stratigraphy of the site.