The Historical Evolutionary Concept and Its Impact on Population - Term Paper Example

In spite of the fact that humans exhibit genetic diversity and mutations through generations, does our inability to categorically chart our evolutionary process give us the right to believe that we are not subject to the laws of evolution?. There is a congruence of scholastic opinion as well as research findings to indicate that human evolution is a matter of genetic diversity and mutations. However, the path of human progression through the ages is riddled with gaps and contradictory findings. However, these lacunae in no way takes away from the fact that evolution was and still is an ongoing, dynamic process. The inability to chart the human evolutionary process in a categorical manner does not mean that the specie human sapiens is not subject to the laws of evolution, in spite of the diverse assumptions and hypotheses to the contrary. The very first such assumption is to do with the fossil records, the findings of which did not occur in a chronologically uniform manner. The earliest fossil record known to science is said to be Aegytopithecus sp a small animal, the size of a spaniel. This fauna is believed to be an ancestor of the humans, as also the modern apes, although quite distinct from all the other primates. It existed in the latter part of the Oligocene era, around 30 million years ago. Since the animal represented the dawn of apes as well as humans, it was termed the ‘dawn ape’. 10-15 million years passed before the lines leading to the great apes and humans began to diverge. 20 million years ago Dryopithecus appeared exhibiting ape like features and 5 million years later Ramapithecus entered the evolutionary arena. It is exactly these rather long intervals of time about which we are completely dark about the onward momentum of the evolutionary process that make some people think that scientists have failed to categorically chart the human evolutionary process. However, there is another side to this argument. It has to do with the terms hominid and hominidae. A hominid comes under the family of hominidae that includes every creature, extinct or living and closely akin to Homo sapiens than to the chimpanzees. It was the great anthropologist Leakey who coined the term (Leakey, et al. 2001). The term is Leakey’s own way of recognizing the intimate evolutionary relationship that existed among human beings, chimpanzees and gorillas (Gee, 2001). This he did in spite of the already mentioned gaps in time. There are other assumptions and arguments going around denying the importance or even prevalence of the laws of human evolution. This is a deliberate attempt to establish that humans are not subject to the laws of evolution and most are far fetched in the extreme. One theory going around and gaining ground, particularly in the United States subscribes to the Creationist view of all living beings as depicted in the Genesis of Old Testament. They are more interested in discrediting evolution by the simple expedient of ignoring all discoveries of hominid fossils. As in many a field of human endevour, hoaxes and mistakes can at times occur in science too. Creationists cherry pick such examples in an effort to prove that these hoaxes and mistakes are proof enough to establish the weakness of science and its theories, particularly the theory of evolution. This is a gross misinterpretation of the very nature of science which advances by learning from its mistakes and drawing confidence from its successes. The scientific method has this built-in, self- correcting mechanism which is a potent asset of science. All scientific hoaxes are soon exposed and rectified and those who do so are not creationists but the scientists themselves. All that the creationists do is to read about such exposes in the newspapers and watch them on TV and claim that it was they who exposed them in the first place. Ironically, the modern Indian savant Osho, whose disciples hail more from the Occident rather than from the nation of his birth, when asked whether there was a God, replied that there was no God because there was evolution. Another criticism leveled against evolution is that it is only a mere theory. The intention of this argument is to show that evolution is either unproved or that it is merely Darwin’s opinion rather than evidence or fact. Those who advocate this idea has mistaken impression as the meaning of the term theory, To them the word means conjecture at best whereas in science a theory is an explanation of the world that puts forth predictions that are testable. In the case of evolution, the theory indicates the diversity of species as well as their ancestry. A noteworthy example of this is the modern synthesis of Darwin’s natural selection and Mendel’s inheritance. Like all scientific theories, this modern synthesis is also continuously debated, tested as well as fine tuned by the scientists. And there is almost unanimous consensus in the scientific community that this synthesis is the only potent model that brings together all the known facts about evolution. Then there is the pseudo scientific objection that the concept of evolution is contrary to the second law of thermodynamics which states that "the entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium". This in effect means that the entropy of an isolated system has a tendency to either increase or remain constant and not decrease. Proponents of this argument state that the theory of evolution is in contravention to this law of physics by requiring a fall in entropy over time (Lambert, 2002). Then there are some who argue that certain mechanisms of evolution such as mutation are quite unable to bring about new information. Citing information theory, creationists like William Dembski posits that life exhibits specified complexity and no generation of fresh information is possible without the prevalence of an intelligent agent, it is quite impossible to generate information that is required to bring about specified complexity. However, the scientific community has dismissed all such claims. Fresh information is indeed generated regularly during the process of evolution, whenever a gene duplication or novel mutation occurs. Such examples of a dramatic nature have been noticed in the recent years with like the evolution of specie of bacteria that consumes nylon, by developing fresh enzymes to digest a material that came into existence only during the very modern era. As mentioned earlier the enormous gaps in time between the discoveries of human fossils are the reason behind the inability to chart the evolutionary process. But here too, new discoveries are being made to fill these huge gaps. Two finds that support Certain fossil finds that occurred recently goes a long way to fill these chronological gaps. One of the finds, discovered in Africa in the 1970s, was a skeleton of Lucy, an early ancestor of human beings. More fossils began to be found in the same geographical area providing satisfactory answers according to researchers. Lucy’s almost half of an adult skeleton measured 3.5 feet in height and belonged to a hominid called Australopithecus afarensis which lived between 3 - 3.6 million years ago and considered by many scientists as an ancestor of homo sapiens (Wood & Collard, 1999; Wood & Richmond, 2000). Although Lucy’s skull, jaw and teeth were very much like that of apes except for the reduced canines and snout and, larger post-canine teeth. This was followed the discovery of new fossils of Australopithecus anamensis, a most primitive ancestor that lived around 4.1 million years ago, according to a University California, Berkeley biologist Tim White. It was discovered in Middle Awash, Ethiopia in the Afar desert region. Time White and his team states that the new fossils are a missing link between the early as well as later forms of Australopithecus and an Ardipithecus, a much more primitive hominid. According to White, this discovery fills the gap between the Lucy species of 3.6 million years and Ardipithecus ramidus of 4.4 million years. With the discoveries of the fossils of Australopithecus anamensis in Ethiopia (White, et al., 2006) were published, most researchers are of the opinion that Australopithecus anamensis was an ancestral of Australopithecus afarensis (Gibbon, 2006). Then in 1983, a small monkey-like fossil was discovered and scientists named it the Darwinian masillae. This fossil had been cut into two and disposed off to private collectors. However, a group of researchers under the leadership of Jorn Hurun of the University of Oslo Natural History Museum brought the fossil together. It was an unbelievably complete fossil, something never heard of in the primate records. Reporting this discovery, The Times newspaper reported that the creature which inhabited the earth 47 million years ago, brought together the primate family tree that was split into two separate branches and ultimately led directly to the humans. The paper says that this fossil could even spot the point from which the evolutionary lineage diverged. The anatomy of the creature indicates that it has a close affinity to the human branch and could as well be the ancestor of old of humans as well as their closest animal relatives. It is expected that with more such fossil findings, the chronological gap will slowly fill and everything will soon fall into place like a well-define jigsaw puzzle. References Gee, H. "Return to the Planet of the Apes." Nature 412 (2001): 131-32. Gibbon, A. "Fossils Clinch Identity of Lucyís Ancestor." Science 312 (2006): 178. Lambert, F. "Disorder — A Cracked Crutch For Supporting Entropy Discussions." Journal of Chemical Education 79 (2002): 187-92. Leakey, M. G., F. Spoor, F. H. Brown, P. N. Gathogo, C. Kiarie, L. N. Leakey, and I. McDougall. "New Hominin Genus from Eastern Africa Shows Diverse Middle Pliocene Lineages." Nature 410 (2001): 430-40. White, Tim D., Giday WoldeGabriel, Berhane Asfaw, Stan Ambrose, Yonas Beyene, Raymond L. Bernor, Jean-Renaud Boisserie, Brian Currie, Henry Gilbert, Yohannes Haile-Selassie, William K. Hart, Leslea J. Hlusko, F. Clark Howell, Reiko T. Kono, Thomas Lehmann, Antoine Louchart, C. Owen Lovejoy, Paul R. Renne, Haruo Saegusa, Elisabeth S. Vrba, Hank Wesselman, and Gen Suwa. "Asa Issie, Aramis and the Origin of Australopithecus." Nature 440.7086 (2006): 883-89. Wood, B., and M. Collard. "The Human Genus." Science 284 (1999): 65-71. Wood, Bernard, and Brian G. Richmond. "Human Evolution: Taxonomy and Paleobiology." Journal of Anatomy 197.1 (2000): 19-60. Read More