Human Ancestory Essay Research Paper Human AncestoryThe

Human Ancestory Essay, Research Paper

Human AncestoryThe evolutionary relationships of Australopithecus and Homo are still argued today among top anthropologists. The direct human phylogeny is not certain, and many links to modern man from four million years ago are possible. What is not argued, however, is that the evolution of man was an evolution from the neck up, rather than from the neck down. After our transition from the arboreal region of Africa to the terrestrial area of the savanna, our physiology below the neck, for the most part, has not changed. As a result, differences among each hominid are not as distinct as some would hope. In example, the comparison between Australopithecus africanus and Homo erectus can be classified as one of degree, not kind. A. africanus, the southern ape of Africa, inhabited the Africa region around 2.6 to 2.0 MYA, while Homo erectus, upright man, encompassed the land around 1.6 to about 1/2 MYA. Despite over one million years of evolution, the differences between the two hominids is limited, and many physical, behavioral, and natural environment adaptations are shared. Instead, a slow, progressive evolution of man is represented between A. africanus and Homo erectus.During the mid-nineteenth century, the great scientist Charles Darwin predicted human evolution to be in Eastern Africa. Sure enough, in 1851 a Dutch anatomist named Eugene Dubois discovered the remains of a hominid at the East African Coast that was classified Homo erectus because of its depiction of bipedalism. Other specimens that represented Homo erectus were excavated in Asia, and the Peking Man for a while, was thought to be the oldest descendant of man (Reader 91). This belief held up for a while until Professor Dart found the first fossil of A. africanus at Taung, South Africa in 1924. This fossil was determined to be about one-million years older than the fossils of Homo erectus. Unlike Homo erectus, however, A. africanus did not move out of Africa. It was only conditioned to survive in the savanna of Southern Africa. On the other hand, remains of Homo erectus have been found in areas of the Old World such as Java, China, Near East, and Northern Africa. How is it that Homo erectus was able to survive the harsh glacier climate of Asia. This question can be answered by examining the physical and behavioral adaptations, most similar but a few important differences, that each hominid endured during its escapade on earth.Even with approximately one million years of evolution, some adaptive physical characteristics between A. africanus and Homo erectus remain the same. There is no projection of bone where the chin would be in either hominid. The brain in both hominids is behind the face and each lack a forehead. This similar characteristic exemplifies the fact that the evolution of man from the neck up was an extremely slow process. In the A. africanus, a clear tendency to the reduction of the jugate (paired) teeth and the growth of the front teeth show that A. africanus could move its jaw not only up and down like a chimpanzee, but now sideways for better chewing purposes. The evenness of the canines with the tooth row in both A. africanus and Homo erectus indicate an omnivorous diet (Guilaine 34). In the movie Mysteries of Manhood by National Geographic, an electron microscope of tooth wear from an A. africanus compared to tooth wear of A. robustus, shows that the A. africanus must of ate soft foods, again indicating an omnivorous diet. Another physical characteristic that appears the same in both hominids is sexual dimorphism. Although not as discrete as in apes and baboons, the difference in relative size between males and females remains definitive in A. africanus and Homo erectus. Finally, the most important similarity between the two hominids is their use of bipedalism in locomotion. The single most important distinction between ape and man is the characterization of bipedalism. During the transition from the arboreal region to the savanna, the ability to walk on two legs became essential. The idea of natural selection can be illustrated during the transition to bipedalism. For example, physically, there was a change in balance where now the head must be above the spinal cord. Those certain hominids that possessed the genes for a better balance with the head and the spinal cord most likely lived longer and had a better chance of reproducing more offspring. Behaviorally, bipedalism provided hominids with a greater ability to manipulate the world around them. Field of vision was improved because of an upright position. Also, now hands were free to handle tools or even carry food from place to place. Undoubtedly, the first evolutionary change that man underwent was the transition to bipedalism. The different adaptive physical characteristics range small, mostly due to the anatomy of hominids, that was already established. Height difference between the hominids is largely noticeable. The A. africanus was approximately four feet tall while a finding in Kenya by Richard Leakey of a twelve year old male suggested that this Homo erectus would grow to be about six feet tall. The height difference could be the result of many reasons. One, the diet among hominids was continuously becoming more concentrated in protein as the transition from an herbivorous to a more omnivorous diet was occurring. Secondly, height was probably better for protection because the appearance to predators wo