Wednesday, October 9, 2019

Human Evolution by C.M. Davenport Essay

Since time immemorial, numerous researchers have been done to explain the mechanism by which humans were able to evolve from being ordinary, defenseless creatures in the Eastern African savanna to being the world’s most advance and high-functioning biological creatures that have ever walked on Earth. Scientific findings suggest that the aforesaid transition was characterized by a decision of our earliest human ancestors to leave their four-legged existence on trees and convert to a bipedal lifestyle on the terrestrial landscape. Such transition, which can be said to be one of the most dangerous yet most essential part of human anthropology, was driven by climatic changes in the African region. Consequently, changes in the general atmospheric conditions affected the vegetation and ecological properties of the ancient human surroundings. Scientists speculate that prior to the climatic alterations which is around ten million years ago, the East Africa was heavy forested and catered to a great diversity of tree-dwelling primates. Unfortunately, the end of the Miocene Epoch or around five million years ago, marked the start of the of the arid, grassland condition. These changes have encouraged primates to go down from the trees and convert to a two-legged manner of walking on the African plains. This transition was not easy because the early human ancestors had to face a multitude of predators on land including leopard, hyenas and lions. However, although this was the case, the need to look for food and other forms of nourishment that were no longer present in their original habitat was greater than the impending dangers they were likely to face. Hence, climate changes have commanded the onset of the start of human civilization by allowing early primates to convert to bipedalism and terrestrial living. Next to bipedalism, early human ancestors had to acquire certain bodily adaptations in order to make them fit to their new surroundings. Body adaptations included changes on speed and gait, acquisition of large buttock muscles and longer legs for running and sitting efficiency, evolution of larger body size, better vision, achievement of a sense of balance on body controls and other locomotory functions, and a more complex brain structure, physiology and function. These changes allowed early human ancestors to escape from predators and be able to gather food for nutritional survival. In this case, the author evidently placed much emphasis on the discussion of the running endurance of human ancestors. It was mentioned that along with the other adaptations, the ability to run from predators is also a very notable skill of the primates that allowed them to dominate the natural selection process. Increase in lung capacity, development of the heel bone and arched foot, ability to sweat were some of the changes that permitted running efficiency. Obviously, expansion of lung capacity accounted for a more organized breathing pattern during running activities while the heel bone and arched foot permitted improved upright position for running and load-carrying. The ability to sweat, on the other hand, is presumed to render more benefits to primates aside from thermoregulation. Reports suggest that sweat of early human ancestors were similar to the properties of the modern genetic disorder trimethylaminuria, a condition that makes a person produce sweat that smells like strong decaying fish odor but not decaying human or animal flesh (Davenport n. p. ). The chemical compound producing the odor is flavin monoxygenase 3 enzyme (FMO3) and analysis of this compound from present trimethylaminuria reveal that FMO3 has undergone molecular modifications thereby allowing the persistence of the disease from subsequent human generations. However, chemical rearrangements of FMO3 are also suspected to be the reason why sweat of humans today does not elicit the same kind of smell of the early primates, an event that is presumed to be a part of their survival strategies. Lastly, the acquisition of human intelligence was the final step in the human evolution process. The complex development of bodily functions for running endurance have also allowed for the creation of cells for specialized physiological, and neurological properties. After this, it was not long before behavioral skills were obtained and furnished. And after about five million years, the world witnessed the emergence of the modern human species equipped with all the necessary physical and mental adaptations that allowed them to be favored by natural selection and win against the other primal families. Consequently, the evolution of humans is characterized by a myriad of factors which are yet to be fully investigated and explained but all the findings we have today are enough to conclude that humans must value the properties that we have today because our ancestors have done so much effort just to let us achieve our present stature. Evolution is continuously happening and we will never know if conditions in the past will repeat themselves. Hence, everyone must continue to hone their skills and adapt with the changes of the environment in order to prevent ourselves from being selected against natural selection and for us to continue our dominance on this world.

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