* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download File
Survey
Document related concepts
Objections to evolution wikipedia , lookup
Sociocultural evolution wikipedia , lookup
Punctuated equilibrium wikipedia , lookup
Creation–evolution controversy wikipedia , lookup
Hologenome theory of evolution wikipedia , lookup
Mormon views on evolution wikipedia , lookup
Genetics and the Origin of Species wikipedia , lookup
Paleontology wikipedia , lookup
Unilineal evolution wikipedia , lookup
Creation and evolution in public education in the United States wikipedia , lookup
Jewish views on evolution wikipedia , lookup
Hindu views on evolution wikipedia , lookup
Koinophilia wikipedia , lookup
Transcript
Jace Pincock Terra Davis English 2010 March 30, 2013 The Theory of Evolution, Only a Theory? The topic of Evolution by Natural Selection is currently one of the most controversial topics in the United States. According to a pole done by Gallup, 46% of the American population (approx. 685,974,059 Americans in 2012) believe that the earth and the diversity of all modern plant and animal life originated only 10,000 years ago (Newport). According to the Pew Research Center’s pole on Evolution in 2009, 97% of American scientists accept the Theory of Evolution, which promotes that the earth is 4.5 billion years old. The age of the Earth plays an important role in establishing the validity of either claim. Evolution is attacked by individuals termed by the media as Young Earth Creationists, usually of the Judeo/ Christian or Muslim Faiths who take the biblical or quranic account of creation literally. These individuals in the 46% have not been exposed to the plethora of scientific evidence for Evolution. This is a problem for establishing fact in academia and the further proliferation of human civilization. These individuals indoctrinate their children about things they do not understand. They do not know how Natural Selection works, they do not understand how scientists know the age of the earth or how they date fossils, nor do they understand the different fields of scientific evidence that prove Evolution by Natural Selection is a fact. The goal of this essay is not to disprove the existence of any deity or deities, but to expound on evidence found. This essay is written for those who have been raised in religious homes secluded from scientific knowledge. It is written for those that are unsure and still trying to figure out what they believe about the origin and diversity of life and are curious about evolution. Although the information presented may go contrary to what some religious institutions teach concerning the diversity of life, it is important for every individual to weigh out both sides of an argument in shaping their own personal world view. If you don’t, how can you really know that something is false? Although a full analysis of Evolution is impossible in this essay, a general explanation of the evidences for Evolution is provided. Individuals that do not believe in Evolution simply do not understand what it is. Uneducated misconceptions of the theory are emulated by the mass media in images and phrases. It is understandable why many are lead away from the information. Many parents and leaders of faith institutions attack the credibility of scientists and the theory of evolution; and worn or condemn their congregations from studying it. Religious author W. Hewitt Tier said, “As to that which the Bible calls "science so-called." The latter embraces conclusions based on incomplete or inadequate knowledge, imaginations, suppositions, and the like, which abound in the theory called Evolution. If the public were fully aware that so many of the statements by scientists are mere surmises, there might now be much to complain about.” Eric Snow and Anne Arbor of the Lion of Judah bible group have stated publicly, “Evolution is philosophy, not science.. They (Scientists) assume there is no God, and then interpret all the facts to fit their picture. Some facts could be equally or better explained by creation, not random evolution”. They also stated, “Because the Bible and the scientific evidence don’t agree with the theory of evolution, we Christians should not believe in it.” This lack of trust in science by the faithful and the misconceptions promoted by those who don’t understand Evolution lead many to believe it is a ludicrous magical process. These misconceptions are usually the only idea these groups of individuals have of Evolution. Many of these individuals will ask or make the following misconceptions of the Theory of Evolution: “Do you really believe that humans came from monkeys?”, or “Do you really believe that something can come from nothing? Another example is “Humans are too complex to have evolved.” I have also heard countless times the term “survival of the fittest” when explaining evolution or the statement, “The Theory of Evolution is only a Theory”. These questions, statements and ideas about evolution reveal an overall lack of education concerning its definition and how the process of Natural Selection actually occurs in nature. To better understand the meaning of the term theory the definition must first be stated. Richard Dawkins, a renowned biologist in his book, The Greatest Show on Earth defines what he believes scientists mean when using the word theory, as in the Theory of Evolution. He shows that according to the Oxford Dictionary, there are two main definitions used when defining the term Theory. The first use is a scheme or system of ideas or statements held as an explanation or account of a group of facts or phenomena, confirmed by observation and experiment; and held to be the general laws, principles, or causes of something known or observed. The second use is a hypothesis, proposed as an explanation, an idea, speculation or conjecture about something, usually an individual’s view, notion, or belief. These are two completely different uses for the same word. When discussing the Theory of Evolution, Dawkins argues that scientists use the first definition stated. In other words Evolution is not simply an idea, but a fact; tested and proven to have occurred and continues to occur today. The examples I will give are all derived through the scientific method and are fact based. Those that are skeptical are invited to research and test the information for themselves. To better understand Evolution one must first know what it is and how it works. Evolution is the change in inherited characteristics of biological populations over successive generations. (Barton) Evolution explains the diversity of life at every level of biological organization, including species, individual organisms and molecules such as DNA and proteins. Charles Darwin and Alfred Wallace were the first to formulate a scientific argument for the theory of evolution by means of natural selection (p.16). They explained what Natural Selection is and how this process is the means by which evolution takes place. Natural Selection is the process by which biological traits survive and are passed on to future generations. A basic explanation of the process of natural selection is derived from three facts Darwin, Wallace and modern scientist have discovered about populations. First, more offspring are produced than can possibly survive; second, traits vary among individuals, leading to different rates of survival and reproduction; and third, trait differences are heritable. When members of a population die they are replaced by the progeny of parents that were more adapted to survive and reproduce in the environment. The term coined by Herbert Spencer, “Survival of the fittest” is a misconception of the theory of evolution. A more correct term is, “the survival of the fit enough”. All living breathing organisms need nourishment to survive or continue existing. (p. 16) Things like the climate, weather, rocks/land and water, or non-living non-breathing things, do not need nourishment to continue existing. This need of nourishment against those things that do not need nourishment ensue a “struggle for survival”. Sources for nourishment, i.e. food, are limited on the planet, this fact creates another form of struggle for survival within living species. The combination of the two make up the opposition to sustained life. The living species that are fit enough to survive against the pressures of other living species for food and non-living things, is the basis that stimulates the process of natural selection and evolution. Those fit enough to overcome the opposition, pass on their genes and traits to further generations which in turn causes variation and change to occur in the traits of those species. To help paint the picture of the process of evolution and natural selection allow me to share an example of evolution from contemporary history. During the industrialization of 19th century England, the peppered moth, Biston betularia was observed. The moth has several genetic forms; however the most common is the typica or white form, which is ivory colored with peppery black spots; and the less common carbonaria form, which is pure black. English natives were used to seeing the white form of the moth flutter around and land on the bark of trees in the forests. However English Naturalist J.W. Tutt and his colleges noticed that after industrialization began, the moths started changing colors. Almost 100% of the white moths in some locations were now completely black in color. They began to question the cause of the change and analyzed their environment to find clues to the mystery. They quickly discovered that soot from coal smoke pouring out of the homes and factories covered the trees. Tutt soon theorized that this must be the reason for the change. But how can this be? Did the coal alter them or did some magical process make the moths evolve and change color? Further analysis and testing showed the process of color change was due to natural selection and evolution. Tutt noticed that the black moths were more camouflaged to their environment against the soot cover trees than their white colored counterparts. This gave them a selective advantage over the white moths who were easier to be seen by predators. This over eating due to color lead the white moths to near extinction and the increase in black colored moths. Other areas that were less polluted were also analyzed and the exact opposite had occurred. Almost all of the black moths had been eaten by predators because they were easier to be seen against the lighter tree bark than the white moths. The moths in both situation were fit enough for their environment. They were also “fit enough” to survive the attack of predators. Both species repopulated, passing on their genetic color genes to future generations which stimulated the evolutionary change. Evolution from white to black and in some areas and black to white had occurred in real time. This is how evolution and natural selection work in nature. (Coyne, p. 111-115) Modern genetics and tests of this moth species have shown that the gene that creates color characteristics, differ only by mutation of one gene. Genetics will be explained later, but this is an example of how evolution occurs at the micro level and sheds light on how animal and plant life have evolved at the macro level over billions of years on our planet. Many individuals question how scientists know the age of the earth and fossils. This leads them to discredit anything scientists say about the past, especially the Evolution of species. The discoveries of physics and chemistry eventually lead to the discovery of radioactivity in 1896 by the French scientist Henri Becquerel. Radioactivity in short is the measurement of how radioactive an element is. A Radioactive element is an element that loses energy in the form of Alpha particles, were the nucleus of an atom loses protons; Beta particles, were the element loses electrons or positrons; and Gamma particles, which are emitted when an atom goes through an excited state of change. Through modern Quantum Theory and Mathematics, equations have been formulated that help physicists and chemists calculate the half-life, or the time it takes for these radioactive substances’ atoms to decay in half. (MacRay) Thousands of experiments have been done on the radioactive elements, each element having a half-life less than a human lifetime to ensure decay actually occurs. All of the scientist’s mathematical formulas proved 100% accurate to the actual half-live decaying rates observed. Half-life theory is therefore has been proven a fact. Some elements have extremely long half-lives, an example of one of the longest half-lives and its cycle decay is shown below: Modern technology and machinery that use gas proportional counting, liquid scintillation counting and counting through accelerator mass spectrometry are used to detect the atomic activity of substances and measure the radioactive loss of elements. When these absolute dating techniques are used and a decay amount has been discovered, math is applied using half-life information to reverse the numbers and calculate a date. Modern dating methods used are: Radiocarbon dating or “Carbon Dating”, Uranium-lead dating, Samarium-neodymium dating, Potassium-argon dating, Rubidium-strontium dating, Uranium-thorium dating, Fission track dating, Chlorine-36 dating, and Luminescence dating methods. (MacRay) All of these methods have been used to date rocks, fossils and other elements/substances on our planet. Element samples from the moon and thousands of samples from the earth have been tested; the oldest minerals discovered to date are small crystals of the element zircon, from the Jack Hills of Western Australia. Their tests revealed that they are 4.404 billion years old. The accepted consensus by scientists today is that the age of the Earth is approximately 4.54 billion years. (p.81) For the Earth to be 10,000 years old or less defies the laws of physics. Now that I have defined evolution and shown how science can date elements lets discuss further evidence for Evolution. Evolution is an extremely slow process taking millions of years to occur. (Barton, p.87) One of the strongest evidences for its existence is the discovery of fossils. These specimens of previously living animals and plant species shed light on the world long since passed. Paleontologists and geologists have proven that stratigraphy exists in the Earth’s Crust. Stratigraphy is a branch of Geology that examines the different horizontal rock layers in the Earth. Radiometric dating of these different layers has proven that the deeper the layer exists the older it is, not accounting vertical earthquake shifts. Fossils found by Paleontologist have been categorized into the Fossil Record and tested by layer or by Geochronology. Thousands of samples around the world have been compared and each specimen matches those found at the same depth in other places of the world. This confirms that certain species lived before later species, some like the dinosaurs lived hundreds of millions of years ago. (p.253) The scientific study of plate tectonics also provides very strong evidence for Evolution. Plate tectonics is the study of the large-scale motions of Earth’s outer core or lithosphere. Plate tectonics explain the concept of continental drift. Originally all of our modern continents were grouped together in a supercontinent known as Gondwana. Beginning about 165 million years ago the plates of the lithosphere began moving apart tearing Gondwana into several pieces, eventually moving to the places they currently are today. As the years rolled on an amazing thing occurred. Evolution began taking place in these now isolated continents, dramatically changing the diversity of animal life on the Earth. The fossil record also supports this point. Fossils are the same around the world until this point in time. (p.254) The evolution of Marsupial Mammals in Australia and New Guinea is one example. These mammals aren’t found anywhere in the continent of Asia or America. This answers the question to why animals are so unique around the world. It also explains why some species are only located in one place on the planet. A study of the subfields biostratigraphy and chronostratigraphy shed further evidence for evolution. As stated earlier the geological history of the planet has been mapped and categorized by era and time up to 3.8 billion years ago. Biologists have also mapped the world’s known animal skeletal structures throughout every era of Earth’s history in a work known as the Tree of Life. (p.252) An individual can follow the evolution of any species back to its ancestor through its skeletal make up. An example of bone categorization from the Devonian Period, around 375 million years ago-when life began moving from water to land, is given in the diagram below: Fossil discoveries of the evolution of complex organs such as the eye, the ear and the heart have also been found and mapped over the ages. All of life on the planet originated from a universal common ancestor. This slow evolutionary process also proves true for our human lineage. Humans did not originate from monkeys. Humans share a common ancestor with modern monkeys. The images seen of an ape gradually turning into a man is a misconception portrayed by the media. Paleontologists have found human fossils mapping out each evolutionary period of our species. (p.725) The earliest documented members of the genus Homo are Homo habilis, found in Africa, which evolved around 2.3 million years ago. During the next million years an increased process of evolution began with the emergence of the Homo erectus. Fossils have shown that Homo erectus and Homo ergaster were the first of the hominina to leave Africa, and these species spread through Africa, Asia, and Europe between 1.3 and 1.8 million years ago. These species were the first of our ancestors to use fire and complex tools. (p.725) Those that remained in Africa evolved into Homo heidelbergensis, Homo rhodesiensis and Homo antecessor, modern humans evolved from this line. The Archaic Homo sapiens are known as the specific forerunner of anatomically modern humans. They evolved between 400,000 and 250,000 years ago, then migrated out of the Africa some 50,000 to 100,000 years ago; replacing local populations of Homo erectus, Homo denisova, Homo floresiensis and Homo neanderthalensis. A diagram of the ape evolutionary tree and a diagram of the evolution of the human skull is shown below: The modern scientific disciplines of molecular biology, genetics, and biochemistry shed further evidence for evolution. The discoveries of DNA, RNA, and biosynthesis have proven that all life on earth is related. For example the sequencing of both the human and chimpanzee genome, share DNA sequences ranging between 95% and 99%. Other animal and plant species that originated from a common ancestor share similar, almost identical DNA sequences to those in the same family. (p.182) The point of the matter is every field of science has come to same conclusion that life evolved over 3.8 billion years ago from a common ancestor and the Earth is at least 4.5 billion years old. There is a reason that 97% of scientists believe in Evolution (Pew Research). New discoveries are being made every year that solidify the Theory of Evolution as a fact. For those still formulating their beliefs about the origin and diversity of life, the evidence is vastly before you. Study it; hear the counter argument that might be against what your parents or religious leaders have taught you. If it is false now you know it’s false, but if it is true why might your religious leaders have keep this information from you? It becomes plainly obvious that Evolution by Natural selection is the means by which life originated and diversified on this planet. Works Cited Barton, Nicholas H. Evolution. 1. New York: Cold Spring Harbor Laboratory Press, June 2007. Print. Coyne, Jerry. Why Evolution Is True. 1st. New York: Penguin Company, 2009. 111-115. Print. MacRay, Andrew. "Radiometric Dating and the Geological Time Scale Circular Reasoning or Reliable Tools?." Talk Origins. 12 Sep 2012. Web. 2 Apr 2013. Newport, Frank. "In U.S., 46% Hold Creationist View of Human Origins." Gallup. (June 1, 2012): n. page. Web. 2 Apr. 2013. "Public Praises Science; Scientists Fault Public, Media." Pew Research Center For The People And The Press. (July 9, 2009): n. page. Web. 2 Apr. 2013.