Special issue in the Journal of Physiological Anthropology
Shigekazu Higuchi, Kyushu University, Japan
Monique K Lebourgeois, University of Colorado Boulder, USA
Raymond Najjar, Singapore Eye Research Institute, Singapore
Physiological anthropology is the study of human adaptability to the environment and its diversity. This collection focuses on sleep and biological rhythms across the lifespan. Although sleep is one of the basic physiological needs of humans, many people in modern society have various problems with sleep. Sleep deprivation not only causes daytime sleepiness and reduced work efficiency but also leads to various long-term health problems. These sleep problems are also caused by circadian rhythm disturbances. Humans have circadian rhythms adapted to the natural light-dark cycle, but artificial lighting at night is known to adversely affect sleep and circadian rhythms. In addition, although humans are a diurnal species, night shifts and shift work, which are essential in modern society, have a significant impact on circadian rhythms and sleep. There are also effects from the use of the Internet and media devices. Behavioral restrictions due to unexpected spread of infectious diseases, such as COVID-19, can also affect sleep. Thermal and noise environments also affect sleep. Furthermore, there are individual differences not only in the effects of the environments but also in sleep and circadian rhythms themselves such as evening and morning preferences. Mechanisms underlying individual differences in sleep and circadian rhythms include various factors such as growth, aging, photoperiod, and genetics. Cultural differences also exist. These characteristics have been clarified through both laboratory experiments and field studies.