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Scientific Study of Non-Violence
present day gorillas and chimpanzees, in which minimal use of branches of trees and stones and efficient bipedal locomotion was already present, changes in environmental conditions over millions of years, led to a more skillful use and manufacture of stone tools; efficient locomotion and tool use affecting each other in a feed-back relationship and each being at once cause and effect of the other.
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The above hypothesis is supported by the archaeological discovery of two types of stone tools: simple ones belonging to Lower Pleistocene made probably by members of the genus Australopithecus, a huminid but not yet a precursor of the human being who hunted and lived bipedally away from the jungle in the open, and complex stone tools belonging to a later period of Middle Pleistocene (500,000 years ago) made by members of the earlier species of human being such as Jawa man and Neanderthal man. They thus indicate increasing hand skill with the progressive evolution of man.
More interesting is the discovery of the fossilized skulls of the Australopithecus, Jawa man and Neanderthal man which show that while in the case of Australopithecus, the capacity of the skull was only about 500 cu. cm. in Jawa man it was about 1000 cu. cm. and in Neanderthal man about 1500 cu. cm.
Correlation of the above two group of observations shows that capacity to make and use progressively complex stone tools and increase in the size of the brain are directly related. This appears logical too. Changing climatic and environmental conditions made it necessary for evolving man to make more complex tools and as he thought of them, made them and used them, gradually his thinking apparatus, the brain, increased in size. Other important changes occurred in his brain as well.
Examination of the cortex of the brain of man by Penfield and Rasmussen (1950), has shown that the size of particular areas of the motor cortex controlling muscles is proportional to the skill with which the relevant muscles are used. It has been shown that the areas concerned with the motor control of the thumb and hand are greatly enlarged in man in comparison with comparable areas in the brain of a chimpanzee. This clearly indicates that increasing hand skill which came with tool use altered the proportional representation of this part of the body in the cortex controlling their action. Furthermore, the structure
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