Evolution – Know about Man’s Painful progress

The superficial characters in which the apes and monkeys resemble man are too well known to need enumeration, while the resemblances in structure on which t he comparative anatomists rely chiefly are of a highly technical nature. One distinguishing character of man, readily to be appreciated and most significant for the present purpose, is his ability to walk upright. As we look back over the early phases of man’s slow and painful progress towards a higher form of existence, three factors stand out as crucial in the stages of that advance. Of these the most important is the assumption of the upright posture. When man began habitually to stand and walk erect, as opposed to the occasional assumption of this position of the internal organs and the character of their muscular supports in the human abdomen. This changed the balance of the body and the carriage of the head on the vertebral column or backbone, while releasing the fore-paws and fore-limbs to acquire those functions of arm and hand which have played a predominant part in the development of the specially human activities for which they are a necessity. The upright mode of progression also conferred upon man the advantage in the struggle for existence of a greatly extended flexibility and range in vision and movement, and more especially a freedom in the employment of head, trunk and fore-limb. These advantages made it possible for him to use, adapt and fashion material aids for attack, defense or protection to counterbalance his weakness, as compared with other members of the animal kingdom, in natural means of defenses against his enemies or the rigorous of climatic conditions. They made up for his deficiency in tooth and claw as a fighter and the loss of his coat of fur which once had kept out the cold. Secondly, and scarcely les important than the upright posture, was the change to full stereoscopic vision, a change which begins in the evolutionary scale in tarsius, the little tree shrew. By focusing both eyes on a single object, this alteration in range gave increased accuracy in sight and judgment, with a consequently increased stimulus to the development of the higher functions of the brain. Thirdly came the opposable thumb, which by moving out of the plane of palm and fingers gave evolving man an inestimable advantage over the ape by making the human hand one of the most delicate and efficient mechanisms in nature. It provided an instrument for the accomplishment of the will and purpose of man which, as a supreme product of evolutionary adaptation, is capable with training , of making provision for all human needs and implementing most human desires. These three factors have played preponderating roles in the development of those qualities that have been responsible for the gradual building up of man’s civilization through the ages. So much then is to be inferred from a comparative study of man and the great apes as they exist today. The salient fact which emerges is that if there are resemblances between them which point to a common ancestor, there are differences which are even greater significance.