Why Evolution Is True - Term Paper Example

Why Evolution Is True? The beginning of life on earth has been a puzzle for scientists for many years. Several theories with different explanations have been proposed in the aim of explaining life’s origin. In this paper, I will confer the origin of life basing our attention at the theory of evolution; its origin, supporting evidence, critics, and philosophical, theological and sociological reflections. Some other theories that try to explain the origin of life include; the theory of special creation. According to this theory, life on earth was; as a result, of the creation by a divine force. Most religions believe in a common concept of creation by a Supernatural Being. A commonly accepted account of this theory is found in the Bible, which is inscribed that God created the earth and all its content in five days and by words and on the sixth day He created man from mud. Despite the shortage of evidence to support this claim, the theory was, and it still is widely accepted by people. According to Coyne 2009, “if we came across a watch lying on the ground, he said, we would certainly recognize it as the work of a watchmaker. Likewise, the existence of a well adapted organism and their intricate features surely implies a conscious, celestial designer- God (p. 17). A different theory that got publicity was the theory of spontaneous generation; this theory suggests that living organisms rise suddenly and spontaneously from no-living matter (Lennox, 1982). For example, crocodiles were believed to originate from logs of wood in the water. This theory was widely accepted in ancient Greek and Egypt. The theory was supported by many famously known scientists and philosophers including Aristotle, Descartes and Galileo. However, this theory was disapproved in the 19th century by Louis Pasteur, who through several experiments, proved that life had to originate from other living organisms. Another theory explaining the origin of life is the theory of Panspermia. This theory proposes that living organisms like bacteria exists throughout the entire universe and that through meteoroids, asteroids and other heavenly bodies; they travel randomly until they find planets with ideal conditions for growth. Earth was one of the planets with these conditions and when heavenly bodies carrying living organism collided, life began. Some forms of the panspermia hypothesis suggest that life commenced elsewhere in the universe and arrived here on earth through comets, meteorites or planetary collision (Andrulis, 2011). However, the most scientifically accepted theory on the origin of life is the theory of evolution. Evolution means a gradual development of an organism from a simple state to the complex structure. This concept of gradual development was first discussed by Lamarck, who proposed a theory that evolution was due to the passage of physically acquired traits from parent to offspring. Charles Darwin later, in 1859, proposed a more clear theory that stated that evolution of life was; as a result, of natural selection (Coyne, 2009). Scientific understanding of evolution A French biologist, Jean Baptiste de Lamarck argued that through use and non- use of body organs, species underwent changes to adapt to the changing environment, those changes were passed to their offspring and thus, as a result, of many accumulated changes the emergence of complex organisms. According to Lamarck, the modification of organisms current form are caused by the changes in the surrounding environment and the organisms attempts to adapt to the changes. For instance, Lamarck believed that giraffes had to stretch their necks to reach for food and so their offspring and later generations were born with elongated necks. However, Lamarck’s argument has been widely criticized and disproved because biologically, and acquired traits are not inherited. Despite his attempts to illustrate how acquired traits are passed from parents to their offspring, Lamarck lacked concrete supporting evidence. This theory was disapproved in several ways. First, experiments performed by critiques showed that acquired traits are not passed to the offspring. Examples, an athlete who is masculine due to daily exercising, their offspring did not come automatically masculine. The other way that Lamarck’s theory was disproved was through the study of genetics which showed parents traits are passed to their offspring through genes. Genes however do not carry physically acquired traits. Several years after Lamarck proposed his theory, an English naturalist Charles Darwin in his book The Origin of Species by Means of Natural Selection proposed a different but a more substantiated evolution mechanism. It stated that all living organisms originated from a common simplistic descendant to the complex creatures present and the difference is due to a collection of different traits useful to particular organisms. The idea came to him in a 5 year voyage aimed at exploring flora and fauna of different continents and islands. From September 1854, he devoted his entire time compiling, observing and experimenting of the relation of transmutation of species (Francis, 2007). He argued that offspring born with their parents helpful traits stand a better chance of survival as compared to those who lack. This argument gained substantial evidence from Gregor Mendel’s report that showed that traits were inherited in a predictable way. The theory of evolution of species due to natural selection is founded on the idea that genetic mutations occur in organisms genetic structure (code), the beneficial mutations are preserved and passed to the next generation while the non-beneficial are lost upon the death of the host. This is proved by several facts and observed data. First, it is observed that all organisms increase in a geometric manner in their population. For instance, Salmon fish produces 28 million eggs a year, if all these eggs hatched the seas would be full in the next several generations (Douglas, 2012). An abnormal increase in population of species is not observed, but it increases slowly. This to mean there is natural factors controlling population growth. Darwin gave two explanations of these natural factors. First is the struggle for existence; due to competition from member of the same species (intraspecific struggle) and from members of other species (interspecific struggle) for resources, the weak organism that don’t survive the struggle die living room for only those capable of the struggle. This struggle for existence ensures survival for the fittest. Discoveries related to the concept of evolution The existence of both theoretical and empirical evidence supporting the evolution theory has led to the scientific acceptance of the theory. One of the most direct evidence that evolution has occurred in finding in fossil records. Fossils are remains of once living organisms from the past preserved by natural method like buried underground or buried in ice. By considering the depth at which fossils are buried or by dating (measuring the degree of decay) the fossils, scientists can approximate the period during which the organism lived. According to Coyne (2009), when these found fossils are arranged according to their age, they present clear evidence that organisms have modified structures (p. 31). For instance, the study of Equidae (the horse family) has shown a significant increase of body size, toe reduction and changes in teeth shapes and sizes. This shows that the evolution must have occurred in the horse family to result to these changes. Another source of evolution evidence is found in anatomical record. Anatomy is the study of an organism structure. The study on closely related organisms like animals shows the existence of homologous structures; these are body structures with different functionality and appearance, but all came from one common ancestor. And the example is the limbs of the human, the wing of the bird, and the limbs of other vertebrates have some common basic bones. This shows that they all came from a single origin and due to the difference in environments and needs; they evolved to the different forms. In addition, classified in the same class (species) but inhabit different geographical habitats, tend to have slight differences in their body structures. These differences are attributed to their attempt to adapt to the different environment. The study of embryos also presents supporting evidence on a common ancestor. At their earliest stage of development, most embryos of vertebrates have some features they all share. Features like gills and a tail are present in humans despite having no use for them. The existence of these common features suggests that we originated from a common ancestor. Other than these early similarities of embryos, the existence of vestigial structures also shows evidence of a common ancestor and the occurrence of evolution. Vestigial structures are body parts of an orgasm that has lost its function. We humans have vestigial structures, evidence that we originated from a common ancestor (Coyne, 2009). For example, organs like the appendix and the tail bone do not have any function but they are still presence. This shows that we descended from an ancestor who had used for these organs. The ability of insects and bacteria to form a resistance to pesticides and antibiotics, respectively, show that natural mutation does occur and that once the orgasm with the beneficial mutations survive. For instance, when bacteria form resistance to a certain antibiotic, the ones who haven’t mutated will die leaving the only ones with these beneficial traits. This provides a sample evidence for Darwin’s argument that natural selection is the reason there is existence of complex organisms. Philosophical, theological and sociological reflections on the evolution Since evolution is a theory and it cannot be experimentally tested but is accepted due to its supporting evidence, it different field reflect it differently. A theory is good if it can easily be falsified and it consistently survives all tests, it accepted as a valid theory Coyne (2009). Sociological reflection Sociologically, the proposition of the theory of evolution clarified the position of the male gender in the society. Male individuals have to prove they have what it takes to be superior, so they compete for a chance to reproduce with partners of their own choosing. The theory also brings out females as passive receivers of male attention with little societal functions as that of providing eggs required for fertilization in times of reproduction. From this theory, society can be defined as a form of an organism subjected to same laws and dynamics of evolution. On the other hand, some social crimes are to be blamed on the existence of competition among individual as explained by the theory. Crimes like rape can be linked to the inability of a male to beat competition and acquire a mate. Philosophical reflection From a philosophical point of view understanding our origin, how different we are from other creatures and how we adapt to variations in the environment if one way of philosophical understanding. Evolution theory can be used to shed light of the origin of morality (human conduct). Organisms are guided through their environment by means of the environmental representation which provides perceptual information and appropriate responses. A child, for example, is born in a world that consists of things that are termed as food prey, as dangerous or safe, wrong or right as potential mates among other things. Evolution is used by philosophers in an attempt to understand the origin our moral (Krosgaard, 2010). Due to the proposal of the evolution theory and taking to account the conception of the world that exists independently of an individual, philosophers can conclude that the world does not consist of predators, offspring or prey but rather of organisms with their won existence who takes those positions naturally. Krosgaard (2010) “Intuitively speaking – essential to achieving the conception of the world that we nowadays recognize as practically rational –that is to say, as moral. That women do not exist to bear men’s children and keep their houses, that strong young men are not fodder for older people’s cannons, that people of color were not born to work in white people’s fields – grasping these facts are essential to forming a theoretical conception of the world that is independently of us as well as a practical conception of the world we must relate to.” (p. 30). Theological reflection Scientist and theologists agree that if you either believe in God or Darwinian evolution but not both. This fact results to a challenge to most people who appreciate the advances, as medicine and technology, science has brought to the society but still want to hold on to their faith in the existence of a Supreme Being. The challenge comes in because they do not know how to reconcile the science of evolution and the existence of the supernatural father of creation. According to Keller (2012), “Seekers and inquirers about Christianity can be even more perplexed. They may be drawn to many things about the Christian faith, but, the main question is how they can believe the Bible if it means rejecting science” (p. 1). However, there are some individuals who argue that science and religion can be reconciled because one is not bound in believing once account or the origin of life. They claim that there is more than one way that they believed divine force could have brought about creation. One of the ways could have been through evolution which is proposed by science, Keller (2012). For example, some arguments have been made to show that there could be an evolutionary reason for religious belief. Despite having no scientific consent, they say that the level of religious belief is adaptive and that it is passed from generation to generation because our ancestors believed in survival and reproduction also. According to Keller (2012) “Theologist say that even if science could prove that religious belief has a genetic component that we inherit from our ancestors, that finding is not incompatible with belief in the reality of God or even the truth of the Christian faith” (p. 1). Scientists and evolution believers however do not see a reason as to why a divine force could have used evolution to gain peoples’ faith. Finally, according to Keller (2012), this is just one of many areas where incompatibility of orthodox faith and evolution begins (p.1). Critique and evaluation the theory of evolution The idea of natural selection as presented in simple words as; if individual in a species has genetically different, those with genes that ensure their survival will live to find a mating partner with same survival advantages and reproduce. As a result of reproduction between two ‘super’ individuals, the resulting offspring will possess both genes that give then the advantages they need for survival. For instance, giraffes with shortness genes will be eliminated due to competition of food, so they dies off, and only the giraffes with the genes for the required tallness will survive to reach mating age. According to Coyne (2009), “Because a theory is accepted as “true” only when its assertions and predictions are tested over, and repeatedly confirmed, there is no one moment when a scientific theory suddenly becomes a scientific fact” (p. 27). Although the Darwinian theory of evolution has a significant number of supporting evidence, it has not been proven scientifically. It is a theory that relies on interpretation of already existing findings from different fields of science like biology, genetics and paleontology. Several questions can be rise to challenge it. Below are some of the challenges that are directed to the theory. First, natural selection may not certainly result to evolution. Due to the absence of experiment to show the evolution in progress, it can be argued macroevolution is; as a result, of some other undiscovered forces and not natural selection. It can also be argued that on the level of microevolution can be brought about by accidental mutation of an organism’s genes but at the level of macroevolution, these structural changes can not be; as a result, of mutation because no matter how intense the impact of mutation is, an animal will still remain an animal and plants remain plants. Secondly, the fossil records do not account for intermediate transformation. There is a missing link in the transition of the ancestral body organs to the body organs of their immediate successor in the evolution chain” (Coyne, 2009). The absence of this evidence disqualifies scientist to saying with absolute certainty that evolution actually did occur. Thirdly, studies from molecular biology also provide evidence supporting evolution. In the cellular level, the cells of all living organisms which are the basic building structures of living organisms’ body are made up by similar building blocks. At the molecular level, different species share genetic homologies as well as anatomical ones. A rat, for example, has genes found in humans. The organisms DNA codes resemblance suggest a common ancestors. “By sequencing the DNA of various species and measuring how similar these sequences are, we can reconstruct their evolutionary relationships. This is done by making the entirely reasonable assumption that species having more similar DNA are more closely related—that is, their common ancestors lived more recently. These molecular methods have not produced many changes in the pre-DNA era trees of life: both the visible traits of organisms and their DNA sequences usually give the same information about evolutionary relationships” (Coyne, 2009). Despite these challenges, the Darwinian theory of evolution still holds water, and it is widely accepted as the most substantial explanation of the origin life on earth. And it is taught in schools in several countries all over the world. This theory of evolution is a step closer to understanding the human species and how to adapt to the future expected changes in the environment. References Andrulis, A. Erik. (2011). Theory of the Origin, Evolution, and Nature of Life. Department of Molecular Biology and Microbiology, Case Western Reserve University school of Medicine. Coyne, A.J. (2009). Why Evolution is True. New York: Viking. Douglas, T. (2012). 29+ Evidence for Macroevolution, Scientific case of Common descendant. Francis, A. K. (2007). Charles Darwin and the Origin of Species. Greenwood Guides to Historical Events, 1500-1900. Keller, T. (2012). Creation, Evolution, and Christian Laypeople. The BioLogos Forum Science and Faith in Dialogue Korsgaad. M. C. (2010). Reflection on Evolution of Morality. Havard University. Lennox, J. G (1982). Teleology, Chance, and Aristotle’s Theory of Spontaneous Generation. Journal of the History of Philosophy. Vol (20), Number 3. Read More