Evolution: In order to understand the next twelve pages of this paper, it is necessary to review the basics of biological evolution and its constituents. Evolution is much more than just change over time. For example, a caterpillar changes into a butterfly and the Earth's tectonic plates move, but they are not considered biological evolution because they do not involve inheritance. “Biological evolution…is descent with modification” (Caldwell). That is to say, it involves genetic change that affects organisms down to the amino acids of DNA. There are two types of evolution: small-scale and large-scale. The former consists of certain genes in a population and its frequency while the latter encompasses the theory of common descent in which a variety of species is said to have the same, common ancestor. For example, a child who inherits blue eyes from his or her mother and blond hair from his or her father falls under the category small-scale evolution because it is within a species that the changes in genetics occur. However, if a variety of species including moths, centipedes, and spiders is found to have a lineage tracing back to the first arthropod, this is referred to as large-scale evolution (Caldwell). “Evolutionary change is driven by one thing and one thing only: the failure of a specific population to pass its genetic code down to the next generation” (Feldman). Evolution is a continuous succession of these changes and can only be mapped after something has evolved. Professor David DeGusta of paleoanthropology at Stanford University claims, “As long as organisms pass on some of their characteristics through some kind of heredity there is going to be evolution. And unless survival and reproduction are random, there will be a ‘direction' to that evolutionary change”. What accounts for this direction is the different species that branch to and from a continuous succession of lineages. The root of all biological evolution finds its origins in speciation.
[...] Also, though no such threat has presented itself yet, there exists the possibility of competition, which has the potential to more or less phase out the human race, very much like what modern man did to the Neanderthals. Also, there is a point when too many organisms in too small of an area deplete its surroundings of resources and thus afterwards, die of overpopulation. And the final and most common cause of extinction is when natural habitats disappear and thus the species occupying them have no means of acquiring energy (Palme). [...]
[...] I say this now to the disillusioned majority of the general public: neither is true and human extinction is truly inevitable. When the time comes and we ask ourselves what went wrong and how our rationale and our science failed, we will find no answers. Towards the end, we will know it for it is the curse of intelligence, of knowledge. We will expect it and we'll be waiting for it. It is not going to come as some surprise for the erosion of time will reveal to us the [...]
[...] The Brink of Extinction Cause and Effect Human beings are considered an anomaly, for this species defies precedent and the usual patterns of life. However, it is said that “abnormalities cannot persist forever; they eventually disappear” (Leakey 233). And a cynical Edward Wilson puts it as, “Perhaps a law of evolution is that intelligence usually extinguishes itself. If not a ‘law', then perhaps a common consequence” (Leakey 233). What he means is that intelligence is actually a flaw because it propels the organism it inhabits to eventually drive itself to its own destruction. [...]
[...] However, the two most likely causes of human extinction reside in pseudo extinction and environmental collapse. The former is the process of human beings reproducing selectively and evolving within themselves; the latter will be discussed further in depth in the following section. And last but certainly not the least, there is the maximum allotted time for life sustenance: the lifespan of Earth itself. When the sun completes its star cycle and becomes a red giant, Earth will no longer possess the conditions that have provided for life so long. [...]
[...] The second reason is philosophical, for the very progress of human evolution has led us to see other species as inferior. And last, but not least, there is the matter of practicality: what measure is the level of complexity to be determined? There is no obvious way to measure (Leakey 91). There is no definite scale upon which the superiority of a species is measured, for each species has different values and characteristics that in its own species separate it from each other. [...]
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