The History Of Evolution Biology Essay

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The history of evolution is an intricate and amazing tale of adaption and hardship, telling more about the history of the hominid ancestors and species. The origins of humankind have fascinated scholars for centuries, a search that was once shacked with the chains of theological dogma. Then in 1859, Charles Darwin's Theory of Evolution and natural selection opened up a limitless expanse of prehistoric time for the complicated process of human evolution. Approximately four million years ago a miracle was beginning to happen; a giant leap in evolution was taking place. The hominids were moving out of the trees, out of the forest and beginning to walk upright out on the open plains. The change from Quadrupedalism to Bipedalism was the most significant adaption that ever happened to the early hominids. It is theoretically believed that the adaptation occurred because of the environment, feeding habits, thermal regulation, and behavioural mechanisms. Have you ever wondered how the hominids managed to survive in such harsh demanding condition? Maybe the early species of hominids were were a lot smarter than the modern human thought, because of their impressive accomplishments throughout the stages of evolution of development that aided their survival. The word Hominids denotes all the members of the family of humans Hominidae, who have close links with our last common ancestor of humans and living apes. This group of fossil-Hominids is included in the super family of apes, the Hominoidea and they are called as Hominoids. Our list of hominid fossils is not a complete one, yet it serves as a good outline to understand human evolution. A generation ago, human evolution was thought of a ladder through time, with an apelike ancestor at the base and the modern human at the top. As for humans, they first appeared at when toolmaking began. This was the reasoning that caused the great controversies of the 1960s as to be the earliest toolmaker. Was it Australopithecus, or some closely related hominid form, like the Homo habilis?

This essay will examine which hominids displayed the first evidence of early human behaviour and the evidence that supports the archaeologist findings. Before the question can be examined there is a need to go back further into the evolutionary tree and identify who were the first human? The earliest hominids were distinctly chimp like in the shape of their bodies; in the sorts of habitats they made their homes, and even the size of their brain. Their social life was probably chimp like as well, demanding a social intelligence on par with that of living chimps. Did they apply the Machiavellian behaviour because of the capacity to understand that maybe chimps have a mind like their own? (Zimmer, 2001) and (Kottak, 2011). The convincing fossil evidence for human evolution begins with Australopithecus. Fossils of this genus have been discovered in a number of sites in eastern and southern Africa. Earliest fossils show them existing about 3.9 million years ago, and the genus flourished until it seemed to have become extinct about 1.5 million years ago. All the Australopithecines were bipedal and indisputable hominines. By 2.6 million years ago, the fossil evidence reveals the presence of at least two, and maybe as many as four separate species of hominines. An evolutionary split seems to have occurred in the hominine line, with one group evolving toward the genus homo, and finally to modern humans, with the others developing into australopithecine species eventually becoming extinct. (Kottak, 2011), (Feder, 2011) and (King, 2007). This was a new species called Homo habilis, or "handy man' appearing about 2.5 million ago,( kottak, 2011) the new hominid probably didn't look much different from its predecessors, but it had a larger brain.( Kottak, 2011) Homo habilis is considered to be the earliest member of the human genus homo which represents the evolutionary transition between the Australopithecines and the later member of the species Homo erectus.(Feder, 2011 ), (Kottak, 2011), (Zimmer, 2001.) and (King, 2007). These first ever fossil remains of Homo habilis were discovered in 1964 in Tanzania East Africa by the Leakey's. Louis and Mary Leakey were the first to identify the first hominid that was classified as the early Homo named Homo habilis. Rickard Leakey found the famous 1470 skull in east Turkana, a large brained rounded cranium that confirmed the existence of H. habilis in no uncertain terms. (Human Evolution?), 2008(Leakey, 1966)(Feder, 2011)(Kottak, 2011)(Gould, Zimmer, 2001.) and (King, 2007.)

If you encounter Homo habilis 2 million years ago, you would have seen little to distinguish the new hominid from Australopithecus. Both species were of similar height and weight, about 1.3 tall and about 40kg to about 100kg. Both species were bipedal, but H. habilis would have looked less apelike around the face and skull. The head was higher and rounder, the face less protruding, the jaw smaller. Some of the most significant anatomical differences involved the more even and less specialized teeth. The molars were narrower, the premolars smaller, and the incisors larger and more spade like, as if they were used for slicing Microscopic wear studies of the teeth have shown that both Australopithecus and H. habilis were predominantly fruit eaters , so there does not seem to have a major shift in diet between the two species. Further evidence from the thigh and limb bones found from Koobi Fora and from Olduvai confirms that Homo habilis walked upright.( Leakey, 1966 ) (Feder, 2011 )(Kottak, 2011)( Gould, Zimmer, 2001.) and (King, 2007.)

The hand bones were somewhat more curved and robust than those of modern humans. This was a powerful grasping hand, more like that of chimpanzees and gorillas than of humans, a hand ideal for climbing trees. The opposable thumb allowed both powerful gripping and the precise manipulation of fine objects. With this ability, Homo habilis could have made complex tools. Homo habilis skeletal anatomy (Human Evolution?), gives a mosaic picture of both primitive and more advanced features of a hominid that both walked bipedal and retained the generalized hominoid ability to climb trees. Louis Leakey suggested that there was a Pilo-Plestocence hominid with a significantly larger brain then found in the Australopithecus. They made this claim based on the findings at Olduvai Gorge. (Leakey, 1966). Leakey and his team gave the new species a name to the fossil remains, Homo habilis. (Leakey, 1966), (Feder, 2011), (Kottak, 2011),(Zimmer, 2001) and (King, 2007). The fossils found of Homo habilis appeared to have different characteristics to the Australopithecines, by several physical different, such as larger cranial cavity, smaller rear teeth, and skeletal bones which resemble modern humans. The belief is that the more advanced Homo habilis created and used tools. (Leakey, 1966) (Feder, 2011)(Kottak, 2011), (Gould, Zimmer, 2001) and (King, 2007).

There is convincing evidence that earlier species had used tools like bits of bone for digging, or sticks for fishing out termites out of their mounds, similar to what a chimp might do. There is strong fossil evidence to suggest that Homo habilis deliberately hammered on rocks to crack and flake them into useful shapes.( Zimmer, 2001) ( Leakey, 1966) Homo habilis was on average less than 5ft tall and weighted under 100lbs, and could hardly have competed with the lions, leopards that stalked the African Landscape. These hominids were probably scavengers instead, vegetarian diet with left over from predators kill. It is envised that Homo habilis presumably had the intelligence to anticipate the habits of predators and scavengers, and used tools to butcher leftovers quickly and get back to safety.(Gould, Zimmer, 2001 )( Feder, 2011)( Kottak, 2011)( King, 2007)and ( McHenry and Coffing, 2000)( Leakey, 1966) The tools remain the most solid evidence of the displayed human traits by Homo habilis. According to Jermaine based on the characteristic tools types, they often described as being from pebble chopper industry. This method of pebble chopper technology originated at least 2 million years ago and was the major method of making tools until about 1.5 million years. Even though the Olduvai tools were poorly made it was a huge step towards having the ability to control the environment. The tools also showed that habilis had the ability to use an object from nature to perform a specific task.( Mchenry and Coffing, 2000 ) Gould, Zimmer, 2001 )( Feder, 2011)( Kottak, 2011)and ( King, 2007).( Leakey, 1966)

The paper has explained the early species and how Homo habilis is the hominid that has displayed the first evidence of early human behaviour. What was Homo habilis like? How did he evolve and what were the main attributes this species had to evolve as the forerunners to modern humans. This hominid species had a brain size of about 750cu cm compared to modern human with a brain size between 1300 to 1350 cu cm. As the hominids became more human they developed the production of tools from materials such as stone, which are valuable artifacts as they have survived to modern times.( McHenry and Coffing, 2000), (Zimmer, 2001), (Feder, 2011), (Kottak, 2011)and (King, 2007). Other artifacts that were needed would have been made from wood, bone fibre and hide, which have not survived like stone tools. (Leakey, 1966). The adaptation to the rigors of prehistoric African life enabled members of the Homo habilis species to survive for more than 500,000 years. A small improvement but is prevalent today in modern humans is the inner ear bone has changed in shape and size throughout early hominids. Over time these small improvement have changed but it helped them to survive. (McHenry and Coffing, 2000) (Zimmer, 2001) (Feder, 2011) (Kottak, 2011)and (King, 2007)

Was the evolution of humans a burst of rapid change or were there other reasons that contributed to the evolution of our earliest human like ancestor. Our scientific predecessors thought of evolution as a gradual and progressive mechanism. The early East Africa follils suggest a very different scenario, coinciding with that of the current view of evolution as a punctuated equilibrium, long periods of relative stability punctuated with bursts of rapid change caused by new, selective pressures resulting from altered conditions perhaps environment change or alterative in the organism itself. (Leakey, 1966)(Feder, 2011)(Kottak, 2011)(Gould, Zimmer, 2001.)(King, 2007) and (McHenry, and Coffing, 2000).

Such a rapid change could have taken hold during the brief 500,000 years that separate A. garhi from Homo habilis. Whoever was the first toolmaker, the development of stone tool technology gave its inventors a major advantage over other hominid species. Stone hammers and flakes let them exploit predator kills, and a shift to an energy rich, high fat diet, which could lead to other manner of evolutionary consequences. During the millennia that separated early Homo habilis from Homo erectus, who appeared in East Africa about 1.9 million years ago. In the fossil evidence there were further modifications in the hips and limbs for bipedal locomotion and a reduction in sexual dimorphism. The primitive body form and sexual dimorphism characteristic of earlier hominids vanished only with the emergence of the much more advanced Homo erectus. The cause of these changes of evolutionary pace remains a system, although some authorities suspect climate changes, especially cooler temperatures played a role. (Leakey, 1966), (Feder, 2011), (Kottak, 2011), (Zimmer, 2001) and (King, 2007.)

In conclusion which hominid showed the first evidence of early human behaviour and what evidence is there to support the finding of Archaeologist? This essay has outlined the evidence to support the theory that the answer to the question is Homo habilis. Homo habilis is said to be a remarkably successful species, whose fossils are said to be found as far away as Indonesia showing us that they grew in large numbers quickly and shifted their places of residences too. This explains why the Australopithecines become extinct and Homo habilis greater survival abilities enabled them to exist. The evidence is from leading Archaeologist Louis Leakey and family from their findings and fossil evidence in Africa and further research. The information used in this essay is from well documented evidence from recognized text books, journals and readings. Human evolution may have reached a stale mate until new evidence is found. Despite the enormous changes that have wrecked on our environment, major evolutionary changes in humans will not occur in the distant future, compared to the changes that occurred with our earliest ancestors. Modern understanding of human evolution rests on known fossils, but the picture is far from complete. Only future fossil discoveries will enable scientists to fill many of the blanks in the present accumulated knowledge of the patterns of geological deposition, anthropologists are now able to pinpoint the most promising locations for fossil hunting more accurately. In the future further fossil findings, technology advances and advanced techniques, will result in an enormous increase in the understanding of human biological history.