著者

Shizuyo Sutou

出版者

日本環境変異原学会

雑誌

Genes and Environment (ISSN:18807046)

巻号頁・発行日

pp.2014.017, (Released:2014-06-07)

参考文献数

22

被引用文献数

1 1 1

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Bipedalism paved the way to delivery of immature babies and development of the brain after birth. This communication presents the argument that hairlessness allowed hominins to access fire through wildfires, which occurred frequently after a climate shift from a wet to a dry environment 2.5 million years ago (Ma). Initially, naked hominins approached fire for warming, but soon must have come across burnt animals in the aftermath of wildfires. They learned the taste of burnt meat, which must have been a driving force compelling them to become meat-eaters. Hominins must have learned gradually how to control fire and how to repel hairy animals that abhor fire. Because they could neither run fast nor have muscles sufficiently strong to compete with large carnivores' fangs and claws, they chose not to be hunters but robbers. When they found that a carnivore had killed a prey animal, they approached the hungry predator and repulsed it using fire and stones, then claiming the prey intact. This is the core of the human robber hypothesis. The timing of global cooling, the appearance of savannahs, the appearance of transitional humans, decline of large predators, the manufacture of stone tools, and the start of cooking largely coincide at 2.5 Ma. They also smoked out animals from their dens or caves, and robbed them of shelter and territory. Cooked meat is both tasty and easily digested, providing hominins with rich nutrients sufficient to enlarge the brain, while most large carnivores were forced to extinction. Consequently, the use of fire, facilitated by hairlessness, must have played important roles in protecting hominins from cold, in repelling predators, in robbing large carnivores of prey and dwellings, and in providing the brain with nutrients for strong growth into adolescence. Development of the eccrine glands is also discussed as a result of hairlessness.

著者

Shizuyo Sutou Takashi Egawa Hiroki Mori Hiroaki Aso

出版者

日本環境変異原学会

雑誌

Genes and Environment (ISSN:18807046)

巻号頁・発行日

vol.35, no.3, pp.73-79, 2013 (Released:2013-09-03)

参考文献数

6

被引用文献数

2

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The March 11 earthquake and tsunami crippled the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company. Consequently, wide areas were contaminated with radioactive substances. The evacuation zone was set as the area within a 20 km radius from the power plant. People who lived in that zone were forced to evacuate immediately. Fukushima Prefectural Disaster Headquarters (FPDH) and the Japanese Governmental Disaster Headquarters (JGDH) planned to let them return to their homes temporarily and asked for help from related organizations, one of which is the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan. The ministry asked all Japanese universities and colleges to take part in screening radioactivity of the temporal returnees from the areas, with aids of the temporal returning program. We applied to the screening activities and measured radioactivity of the returnees at Bajikoen Off-site Center on July 14-17, 2011, and at Kawauchi Gymnasium or Hirono Central Gymnasium Off-site Center on July 23-25, 2011, in Fukushima Prefecture. During these periods, 4009 returnees in all were screened at these three Off-site Centers. None was found to be contaminated with radioactivity over 13,000 cpm. Before the returnee screening program, emergency screening had been conducted soon after the disaster. In all, 33,598 people out of 78,000 evacuees (43%) were screened during March 12-December 7, 2011, during which 3,686 volunteers were recruited by MEXT for the screening program. This is a tiny fraction of the temporal returning program. FPDH reported that 102 people were contaminated with more than 100,000 cpm out of 259,108 people generally screened from March 13, 2011-October 10, 2012. The 102 were detected only in the screening in March in 2011. No hazardous effect, however, was detected among them, so far. Screening is still underway. The present article was compiled to record aspects of the large scale radioactivity monitoring program planned by FPDH and JGDH.

著者

Shizuyo Sutou

出版者

日本環境変異原学会

雑誌

Genes and Environment (ISSN:18807046)

巻号頁・発行日

pp.2014.019, (Released:2014-06-19)

参考文献数

81

被引用文献数

2

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Three characteristics, i.e., bipedalism, nakedness, and the family reproductive unit, distinguish humans from other primates. Once a hairless mutation was initially introduced, these three could be explained inseparately. All primates except humans can carry their babies without using their hands. A hairless mother would be forced to stand and walk upright to hold a baby. As her activities were markedly limited, the male partner had to collect food and carry it to her to keep their baby from starving. He must have been sexually accepted by her at any time as a reward for food. Sexual relations irrespective of estrus cycles might have strengthened the pair bond, leading to family formation. Savannahs appeared 2.5 million years ago (Ma), which forced hominins to terrestrial life, but the ground was full of danger and a larger brain became advantageous. Wildfires occurred frequently; naked hominins approached fire for warming, but soon must find burnt animals in the aftermath of wildfires. The taste of burnt meat must be a driving force for hominins to become meat-eaters. They must have learned how to control fire and how to repel hairy animals that hate fire. To compete with large carnivores with fangs and claws, they became not hunters but robbers. When robber hominins found that a carnivore had killed a prey animal, they approached the predator and repelled it away from the victim using fire, then claiming the prey intact. Major events such as the timing of global cooling, the appearance of savannahs, the appearance of early humans, decline of large predators, the manufacture of stone tools, and the start of cooking largely coincide at 2.5 Ma. Cooked meat must be tasty and easily digested, providing hominins with nutrients sufficient to enlarge the brain, while most large carnivores were forced to extinction. Thus, hairlessness created humans.