Variation in limb proportions between Jomon foragers and Yayoi agriculturalists from prehistoric Japan

Abstract

Variation in limb proportions between prehistoric Jomon and Yayoi people of Japan are explored by this study. Jomon people were the descendents of Pleistocene nomads who migrated to the Japanese Islands around 30,000 yBP. Phenotypic and genotypic evidence indicates that Yayoi people were recent migrants to Japan from continental Northeast Asia who likely interbred with Jomon foragers. Limb proportions of Jomon and Yayoi people were compared using RMA regression and "Quick-Test" calculations to investigate relative variability between these two groups. Cluster and principal components analyses were performed on size-standardized limb lengths and used to compare Jomon and Yayoi people with other groups from various climatic zones. Elongated distal relative to proximal limb lengths were observed among Jomon compared to Yayoi people. Jomon limb proportions were similar to human groups from temperate/tropical climates at lower latitudes, while Yayoi limb proportions more closely resemble groups from colder climates at higher latitudes. Limb proportional similarities with groups from warmer environments among Jomon foragers likely reflect morphological changes following Pleistocene colonization of the Japanese Islands. Cold-derived limb proportions among the Yayoi people likely indicate retention of these traits following comparatively recent migrations to the Japanese Islands. Changes in limb proportions experienced by Jomon foragers and retention of cold-derived limb proportions among Yayoi people conform to previous findings that report changes in these proportions following long-standing evolution in a specific environment.

Metric characteristics of human limb bones in Asian and Japanese populations

“…However, the Okhotsk people had rather large upper limb bones, like the Neolithic Baikalian people and the Buryats. The radiohumeral indices (R1:H1) of the Jomon people were found to be markedly high, exceeding 80 ('dolichokerisch' in German), as previously reported (Yamaguchi, 1989;Temple et al, 2008). The Micronesian samples were found to have a long and thick humerus.…”

“…Although analysis of variance revealed a significant difference between the samples compared in this study, the crural index (T1:F1) was not significantly correlated with latitude, partly because the Jomon and Ainu peoples were included in this study (Figure 2c). The Jomon and Ainu peoples have very high crural indices among the East Asians, while such indices are low in the Yayoi people, modern mainland Japanese, and Ryukyu Islanders from the same Japanese islands (Yamaguchi, 1989;Temple et al, 2008;Fukase et al, 2012). However, even when the Jomon series was excluded from the analysis, the correlation was not significant.…”

“…That is, the intralimb proportions among the Japanese peoples were complicated by the recent migration (c. 2000 BP) of the Yayoi people (Yamaguchi, 1982;Temple et al, 2008). The second reason is the peculiarity of the Jomon people.…”

The Skeletal Phenotype of “Negritos” from the Andaman Islands and Philippines Relative to Global Variation among Hunter-Gatherers

“…Most recent analyses continue to interpret variation in human limb proportions as being adaptive in response to environmental stress (Temple et al 2008) and relatively stable throughout development (Cowgill et al 2012). This sits somewhat at odds with evidence for plasticity of human body size and limb proportions (Tanner et al 1982;Bogin et al 2002), and evidence that environmental plasticity of many phenotypic characteristics can influence heritability estimates (Wells and Stock 2011).…”

Developmental variation in facial forms in Japan

“…The dramatic changes during the transition between the Jomon and Yayoi or Kofun periods include varieties of cranial and dental non-metric traits, limb proportions, estimated statures, dental sizes and shapes, in addition to facial forms (Brace and Nagai, 1982;Dodo, 1987;Dodo and Ishida, 1990;Matsumura, 1994;Kaifu, 1997;Kitagawa et al, 2002;Temple et al, 2008). These changes in physical characteristics can be explained by the gene flow from the Asian continent, because the suite of biological traits shared between the Yayoi people and later groups is broadly similar to those of the Korean Peninsula and China (Kim et al, 1993;Yamaguchi and Huang, 1995; Doigahama Site Anthropological Museum and The Cultural Relics and Archaeology of Shangdong Province, 2000; Nakahashi and Li, 2002).…”