We are one Species Essay

Document Type:Essay

Subject Area:Biology

Document 1

As narrated by Grammer, Karl, and Thornhill (278), Homo sapiens are characterized with very large brains, with varied capacities and sizes from different populations and genders and with an average size of about 1300 cubic centimeters. The skull was reorganized into what is a thin-walled structure with a flat, almost vertical and high vaulted forehead. The Advanced nature of modern humans’ brains enables them to interact with one another and their environment in new creative and diverse ways. Homo sapiens faces appear to have much fewer heavy brow ridges and pragmatism of other early humans. Our jaws have smaller teeth and are not heavily developed. Homo sapiens existed as far back as 40,000 years ago in Africa and also in Israel. Horner, Victoria, and Whiten (1006), argued that contrary to every other human species, researchers do not recognize there any Homo sapiens individual that particularly gave the species its name. These findings prove that human beings are remarkably similar. The DNA of all human beings living today is 99. alike. As in all species, there is variation among individual human beings, from size and shape to skin tone and eye color. These phenotypic differences can be attributed to the fact that Modern humans have spread to every continent experiencing different climatic conditions and genetic variances. According to Williams et al (340), People of the Central African rain forest are significantly shorter in stature than their neighbors and have become known as pygmies. Other groups expressing pygmy stature are known in the Andaman Islands, Malaysia, Thailand, Indonesia, the Philippines, Papua New Guinea, Brazil, and Bolivia.

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It is believed this short stature was an evolutionary advantage evolving independently several times over the course of human history. Scientists believe the short stature developed as a response to living in a rain forest environment. While rain forests are known for their extensive and complex ecosystems, there is often very little there that humans can eat. This led to theories that the pygmies were short simply because they were not receiving full nourishment. Small stature may have evolved as a way to conserve calories. Recent studies by Williams et al (349) have also show that pygmy stature is more likely a genetic trait that evolved as an adaptation from the environment rather than simply a lack of nourishment. They don’t affect an individual’s survival and are simply a result of genetic shuffling.

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Charles Darwin was a British naturalist who proposed the theory of biological evolution by natural selection. Danton (43) reveals that it was during Darwin's journeys on the British survey ship HMS Beagle that he saw the variations in different species that led him to develop the idea of natural selection. Darwin's experiences on The Galápagos Islands were a catalyst for his thinking about evolution. Darwin defined evolution as "descent with modification," the idea that species change over time, give rise to new species, and share a common ancestor (Horner, Victoria, and Whiten 180)The mechanism that Darwin proposed for evolution is natural selection. An analysis by Mahmood (109) shows that the rates of population growth are not the same, of course, in all parts of the world. Among the industrialized countries, Japan and most of the countries of Europe are now growing relatively slowly while the pre-industrial, low-income, and less-developed areas of the world, with two thirds of the world’s population including some parts of Asia, the southwestern Pacific islands, Africa, the Caribbean Islands are growing at rates ranging from moderate to very fast.

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Further insights by Hull et al (1694) show that the increase occurs in tandem with high fertility rate, high poverty levels, low economic development, poor utilization of natural resources, and heavy dependence on industrialized nations for financing. Resource scarcities, especially oil, are likely to limit future economic growth as its production will come at an increasing cost and expensive oil will eat into world food production Hull et al (1695). The transition in demographics that is tied with economic growth in previous times may be impossible for many nations today. Indeed there is much more genetic variation within human populations than variations between them. Therefore, genetically, humans share much more traits in common than they differ. Therefore, we are all a part of one species: Homo sapiens. The perception of people being members of different races is mainly based on human psychology rather than biological reality.

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Works Cited Denton, Michael. G. et al. Population study of causes, treatment, and outcome of infertility. Br Med J (Clin Res Ed) 291. Mamdani, Mahmood.

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