School of Dentistry at Matsudo, Nihon University


I specialize in physical anthropology, and am currently trying to reconstruct the way of life of ancient people by examining the morphology of their human skeletal remains. I am most interested in why most people live in food-producing societies today. even though ancient people lived in hunting and gathering societies during most periods of human evolution in the past seven million years. In order to answer this question, I am reconstructing the way of life of hunter-gatherers and agriculturists in terms of fertility and survivorship, nutritional condition, subsistence activities, etc., by examining the morphology of their human skeletal remains. I am studying ecological anthropology, cultural anthropology, and primatology and intend to explore the process of human evolution from the viewpoint of childbirth and childcare by examining the pregnancy parturition scars on the female pelvises of the human skeletal remains which indicate the level of difficulty of childbirth.


Skeletal remains of Homo sapiens excavated from Japan, North America, and South America, as well as human fossils, and the bones of primates.


  1. Igarashi Y., Shimizu K., Mizutaka S., Kagawa K. Pregnancy parturition scars in the preauricular area and the association with the total number of pregnancies and parturitions. American Journal of Physical Anthropology, 171: 260-274, 2019.
  2. Igarashi Y., Yoshida S., Kanazawa E. The prevalence and morphological types of non-carious cervical lesions (NCCL) in a contemporary sample of people. Odontology, 105: 443-452, 2017.
  3. Igarashi Y. Frequency of mandibular tori in prehistoric and historic Japanese island populations. Quaternary International, 405: 87-100, 2016.
  4. Igarashi Y., Uesu K., Wakebe T., Kanazawa E. A New method for the estimation of adult skeletal age at death from the morphology of the auricular surface of the ilium. American Journal of Physical Anthropology, 128: 324-339, 2005.
  5. Igarashi Y. “Paleodemography” Encyclopedia of population science. Population Association of Japan (Ed.) Maruzen Publishing, 2018. (Japanese)
  6. Igarashi Y. “Human evolution from the viewpoint of childbirth and childcare” Gendai Shisou. Kurihara (Ed.) Seidosha, pp. 190-204, 2017. (Japanese)
  7. Igarashi Y. “Some comments and questions to the lecture ‘Evolving women: Childbirth and infant helplessness as forces that shaped human evolution’ by Karen Rosenberg” A Japan-based Global Study of Representationsof Race. Takezawa Y. (Ed.) Kyoto Univeresity, 2015.
  8. Igarashi Y. “Mandibular torus” Encyclopedia of paleopathology. Fujita H. (Ed.) Doseisha, 2012. (Japanese)


I have been studying the skeletal remains of Homo sapiens, and wish to study those of pre-Homo sapiens, and also discuss human evolution. Therefore, I am glad to join this project and am looking forward to collaborating with ecological anthropologists, cultural anthropologists, and primatologists.