A Theme in Morphological Changes Throughout Human Evolution - Research Paper Example

Running head: A THEME IN HUMAN EVOLUTION A theme in human evolution Introduction The universe comprises various materials that undergo different processes resulting to an alteration in their form after some period. Similar processes have been seen to influence the morphology of various organisms. The physical and sociological processes among various organisms often contribute to some alterations in the traits in such organisms. Some aspects of the altered traits may be passed on to the next generation. The process will continue in response to the prevailing conditions and leads to a significant change in the end. There have been various theories that communities use to explain the origin of man including the religious teachings (Green, 9). Scientifically, the modern man is believed to have gradually evolved from the ancient apes-like creatures and shares certain features with these animals. Taxonomists classify man in the same family with apes like chimpanzees, gorilla, and orangutans. There are fossil evidences that have provided the research scientists with enough proofs of the process of evolution in various organisms (MacKenzie, Arwine & Shewan, 293). The early man depended on wild fruits and vegetations for food. They had large jaws and teeth for this function. The need for man to continue surviving among the wild predators contributed to the increase in the intellectual capacity. The increased intelligence in man led to the invention of fire. Man could now cook food, a process that softens the food material. This contributed to the decrease in size of the human jaws and teeth compared to the olden teeth. This paper focuses much on the structural developments that have been witnessed in the human teeth in the process of human evolution. A thesis statement for the claim The physical and cultural factors have contributed to the morphological changes that have been witnessed in the evolution of man from the ancient ape-like creatures to the modern man. The archeological evidences that support the claim An exanimation of the fossil records for the hominids can reveal much information on the early forms of the present creatures. The study of human remains did not feature until the nineteenth century when archaeologists realized that the culture and the morphology of early man could be revealed by the remains and the tools that were found buried with these remains (Greene, 11). A comparison between the morphology of the different fossils can be made to provide an insight into the relationships that occur between populations of organisms at different stages in the evolution process. Much information regarding the human culture could be obtained through the study of such remains. It has been noted that by studying the bone morphology of the fossils “one can understand the nutritional status, diet, disease processes, factors affecting mortality and life expectancy, biological responses to environmental stressors and aging of our ancestors” (Seth, 19). The teeth of animals will be related to the kinds of food that they consume. The herbivorous animals feed on vegetation and have many large molar teeth for chewing the fibrous foods. On the other hand, carnivorous animals like lion have large canine teeth that are used for killing and tearing the meat of their prey. The early hominids had the ape-like U-shaped dental arcade whereas the modern, man has a parabolic dental arcade. These early hominids and the modern man have the same dental formula of 2.1.2.3= 32. This means two incisors, one canine, two premolars, and three molar teeth on both sides of the upper and lower jaws. However, there is a difference in the teeth structure and size between the early hominids and the modern man. This has been caused by the difference in the kinds of food that have been consumed by man at different stages of evolution. The early hominids were mainly herbivorous and had large molars for chewing the high roughage content foods. The ecological factors and other developments led to the introduction of flesh in the hominids diet. The hominids developed strong and large canine teeth for tearing flesh of hunted animals. Later on, man invented fire and could now cook his scavenged meat as well as the gathered grains. There was, then, no need for strong and large molars for chewing roughages and neither was there a necessity to have large canines for cutting the flesh. The consumption of cooked food by human beings made their jaws and teeth become smaller as compared to those of their ancestors and the apes in the same hominid family. The modern man has some features that distinguish him from his ancestral creatures. The earliest ape-like creatures were quadrupedal and used the fore limbs for grasping objects and other kinds of manipulations. The needs for such functions increased and later on man could go on two feet. There was, then, a need to develop better ways of keeping away from the other predators. This contributed to the increase in intellectual ability of man. There was a significant increase in the brain size. How primatology contributes to the claim Primatology is concerned with the study of the primates with a lot of focus on the apes. It is concerned with the evolution that has been seen in this category of animals, the social systems, their culture, and the ecological systems. The ancient ape-like creatures from which man evolved had morphology that is similar to the present day apes. In the present situation, it has also been observed that there is just a very small difference between the modern apes and the modern man (OneLife, para.6). A study on the structural changes that have been witnessed in relation to the cultural developments among the apes is important in explaining the changes that have been noted in the evolution of man from the apes. It has been noted that modern man and the other apes have certain similarities from a cultural perspective (OneLife, para.9). Their way of life could be comparable to the early apes that are in the human lineage. The earliest creature in the human lineage was Ardipithecus ramidus (Paranthropus) that lived at the same time with Ramapithecus, the ancestor of the modern apes. He was an herbivore and so had strong molars. The records like one on the dental morphology of this creature showed closeness to the apes (Archelogy.Info, para.9). This was followed by different species of Australopithecus. The genus Austrolopithecus showed close relationship in dental morphology with the modern man (MacCurdy & Academy of Natural Sciences, Philadelphia 248). The afarensis was the first of this type. It had the face of an ape with very strong jaws (OneLife, para.14). Australopithecus africanus that followed had stronger molar teeth. It was also an herbivore and had to chew tough plant tissues. The teeth had a shape similar to that of the modern man (OneLife, para.15). Later species like Austrolopithecus aethiopithecus and Austrolopithecus robustus fed on hard to chew diets and had stronger molar teeth and jaws. Homo habilis and Homo erectus also had the massive jaws and huge molar teeth. Homo erectus was muscularly built and stronger than the present day human beings (OneLife, para.17). The species that linked Homo erectus and Homo sapiens sapiens was Homo sapiens (archaic) (OneLife, para.20). The fossils evidences show a relationship between the modern man and the Homo erectus. This species had smaller skull than the previous forms and though slightly larger than the modern man, it had smaller molar tooth. The change in the diet had had influence on the kind of teeth that this species had. Controversial issues The archeological evidences show a somehow steadily increasing trend in the brain size in man during the different stages in evolution. However, there have been controversies on whether the brain size influences the intellectual ability of an organism (OneLife, para.7). Besides, the evolution theory that was developed by Charles Darwin has also received challenges. A look at the studies by Gregor Mendel (1822-1884) showed that Darwin had failed in accounting for the causes of variations in characteristics of organisms that led to evolution (MacKenzie, Arwine & Shewan, 292). Thus, the evolution theory still receives challenges especially due to the difficulty in chronology in the existence of some of the older forms of human beings. Works Cited Archelogy.Info Paranthropus. 2008. 23 May 2011. http://www.archaeologyinfo.com/paranthropus.htm. Green, Kevin. Archaeology, an introduction: the history, principles, and methods of modern archaeology. Third ed. London: Routledge, 1996. MacCurdy, George G. and Academy of Natural Sciences, Philadelphia. Early man: as depicted by leading authorities at the International symposium, the Academy of Natural Sciences. Philadelphia: Ayer Publishing, 1969 MacKenzie, Leslie, Arwine, David K., and Shewan, Edward. Biology: A Search For Order In Complexity. Second ed. Arlington Heights: Christian Liberty Press, 2005. OneLife. The Evolution of the Human. 2011. 23 May 2011. http://www.onelife.com/evolve/manev.html Seth, P.K. Understanding evolution of man: an introduction to palaeoanthropology. New Delhi: Gyan Books, 2003. Read More