Friday, November 22, 2019

Analysis Of Multiple Theories Of Human Evolution History Essay

Analysis Of Multiple Theories Of Human Evolution History Essay The study of evolution in and of itself can be controversial to some. However, within the scientific community it is regarded as the broadly accepted idea that every living thing is derived from what came before and the tiny gradual mutations that arose through millions of years. To that end, there is much debate on certain aspects of particular mutations. Specifically, the debate surrounding the circumstances of human evolution can certainly be seen as contentious. Notwithstanding those who disavow evolution in its entirety, within the scientific community itself, there are several different schools of thought. More notably, the differing theories challenge each other with regard to when homo sapiens first appeared. But while each idea of human progression may differ, they are each rooted in strong empirical, but still limited, evidence. In scientific terms, before establishing how homo sapiens have come to be, we must first examine where they have come from. According to Cynthia S tokes Brown, author of Big History, â€Å"Five to 7 million years ago some mutation occurred in an ape ancestor and survived, and from that single mutation other single mutations kept occurring in the branch called hominids, the bipedal apesà ¢Ã¢â€š ¬Ã‚ ¦These genetic changes took place repeatedly in the same place-eastern Africa.† All major scientific theories regarding human evolution begin with this accepted premise, as Brown states, â€Å"For at least 3 million years human development occurred only in Africa; hominids did not live anywhere else, although apes lived in Europe and Asia as well.† There is an important point to be made in saying that although apes lived in other continents, human development took place exclusively in eastern Africa. One must acknowledge the distinct characteristics of Africa that fostered bipedal evolution in the first place. Eastern Africa, with its abundance of animals and plant life, is significant because of how it became conduciv e to and instrumental in helping shape human evolution. Brown writes, Eastern Africa is tropical; our lack of hairiness indicates that we evolved from tropical animals. To become humans, tropical apes came down from trees to live on grasslands; we are creatures of grasslands, not forests. The geography that could mold human development is found in the Great Rift Valley of eastern Africa. This helps one to understand the origin of homo sapiens and what conditions helped bipeds thrive sometime between 1 and 1.8 million years ago. Additionally, in deriving all of this information one realizes the arduous work involved in documenting and compiling evidence that dates back millions of years. One can recognize the power of human thought and reason, a result of evolution itself. It is in the migration out of Africa where a sometimes contentious debate arises in the scientific community. The distinction is made just after the presence of homo erectus. Whereas one theory describes homo sapie ns in direct lineage to the groups of homo erectus which migrated out of the Great Rift Valley region, known as the Multiregional theory, the more widely accepted thought is described as the Noah’s Ark Theory. The inference made by that name is that we were all in the same boat, Africa, and then migrated out about 100,000 to 200,000 years ago, some million years after the first homo erectus left Africa. Essentially it boils down to the question of whether or not those who left Africa evolved along with those who remained into homo sapiens or that those who left died off as a different species entirely.

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