1School of Dentistry at Matsudo, Nihon University, 2School of Statistical Thinking, The Institute of Statistical Mathematics, 3Department of Mathematics and Informatics, Ibaraki University
April 16, 2020 , Diamond 10
Fertility and survivorship in Jomon hunter-gatherers and Yayoi agriculturalists of Japan were reconstructed by examining human skeletal remains from Jomon and Yayoi sites, in order to see whether there were differences among populations. Fertility was estimated using pregnancy and parturition scars (PPS) in the preauricular area (Igarashi et al. 2019). PPS include three categories: TS0 indicates "no pregnancies and parturitions", TSL indicates "fewer pregnancies and parturitions" and TSH indicates "more pregnancies and parturitions". The percentages of TS0, TSL and TSH in a population can be regarded to be the fertility of the group. Survivorship was based on the ages of individuals estimated by the morphology of the auricular surface (Igarashi et al. 2005). Results show that fertility and survivorship were different among populations. In the northern Jomon population, fertility was high and survivorship was low; in southern Yayoi populations, fertility was low and survivorship was high. In central and western Jomon populations, fertility and survivorship fell in the middle between the extremes of the other two groups. We cannot currently determine whether these differences are caused by the difference of area: climate or subsistence system, or by the era: subsistence system or genes. We would like to examine the fertility and survivorship of southern Jomon populations and of central and northern Yayoi populations in order to better identify the cause of the differences in fertility and survivorship among the populations.