theory evolution

CHAPTER I
INTRODUCTION



A. Background
Since time immemorial man has always questioned the origin of life and himself. Answers to these questions while there are three alternatives, namely the creation, transformation, or evolutionary biology. Definition of biological evolution vary depending on the biological aspects of the review. Some definitions which are common in biology books, among others: the evolution of living beings are the changes experienced by living beings gradually over a long time and lowered, so that over time can form a new species: evolution is the change in frequency genes in populations over time; and adaptive evolution is the changing character of the population from time to time. The evolution has been to unite all branches of biology.
Idea about the occurrence of biological evolution have long been the thinking man. However, among the various theories of evolution that has been proposed, it appears that Darwin's theory of evolution by most to the theory. Darwin (1858) proposed two main theories of species alive today come from previous living species, and evolution occurred through natural selection. The development of the theory of evolution is very interesting to follo based on the pattern of evolution is gradual, based on the direction of adaptation are divergent and based on the result it self always begins with the formation of a new variant.
In its development, Darwin's theory of evolution was challenged (especially from religious groups, and which adopts the theory of creation - Universal Creation), support and enrichment-enrichment. So, the theory itself also evolved so that the theory of biological evolution that we now know with the label "Neo Darwinian" and "Modern Synthesis", is not as pure as that proposed by Darwin. Various terms below is the result of enrichment, which reflects the struggle of ideas and scientific arguments about the theory of evolution: based on the speed of evolution (evolution and the evolution of quantum quasi); based on the pattern (gradual evolution, punctual evolution, and evolution saltasi) and based on the product scale (macro-evolution and micro-evolution).
Topic to be discussed below covers developments and the implications of Darwin's theory of evolution from Darwin's theory of biological evolution on our perspective of the existence of beings and the universe.
B. Purpose
All mortal life made up of cells. Based on fossil evidence found, the cell has existed billions of years ago. However, the question is when and how early life began. We want you to know that the scientists are trying to find answers about the origin of life. From the experiments that have been made, produced several theories.




















CHAPTER II
DISCUSSION



A. History of Evolution’s theory
The roots of naturalistic thinking on biology can be dated to at least the 6th century BCE, with the Greek philosopher Anaximander. Early Christian Church Fathers and Medieval European scholars treated the Genesis creation myth as allegory and believed that natural organisms were unstable and capricious, but the Protestant Reformation inspired Biblical literalism and a natural theology in which species were static and fixed. As emerging science explored mechanical philosophy in the 18th century, proto-evolutionary ideas were set out by a few natural philosophers such as Pierre Maupertuis in 1745 and Erasmus Darwin in 1796.
The word evolution itself (from the Latin evolutio, meaning "to unroll like a scroll") was initially used to refer to embryological development; its first use in relation to development of species came in 1762, when Charles Bonnet used it for his concept of "pre-formation", in which females carried a miniature form of all future generations. The term gradually gained a more general meaning of growth or progressive development. The first published modern use of the word has been attributed to the Edinburgh New Philosophical Journal in 1826, edited by Robert Jameson but arguably authored by Robert Edmond Grant.
The Bible-based Ussher chronology of the 1650s had calculated creation at 4004 BC, but by the 1780s geologists assumed a much older world. Wernerians thought strata were deposits from shrinking seas, but James Hutton proposed a self-maintaining infinite cycle. Georges Cuvier's paleontological work in the 1790s established the reality of extinction, which he explained by local catastrophes, followed by repopulation of the affected areas by other species. He held that species were fixed, and marginalised the ideas of the biologist Jean-Baptiste Lamarck about transmutation of species which were only taken up by radicals.
Geologists such as Adam Sedgwick adapted Cuvier's catastrophism to show repeated worldwide annihilation and creation of new fixed species adapted to a changed environment, initially identifying the most recent catastrophe as the biblical flood. In opposition to this view, Charles Lyell adapted Hutton's concept into a stricter uniformitarianism which strongly influenced the young geologist Charles Darwin during the Beagle expedition. Darwin initially followed Lyell's idea of repeated "centres of creation" of fixed species, but questioned Lyell's views and in 1836, near the end of the voyage, he expressed doubts that species were fixed. Darwin formulated his idea of natural selection in 1838 and was still developing his theory in 1858 when Alfred Russel Wallace sent him a similar theory, and both were presented to the Linnean Society of London in separate papers. At the end of 1859, Darwin's publication of On the Origin of Species explained natural selection in detail and presented evidence leading to increasingly wide acceptance of the occurrence of evolution.
Debate about the mechanisms of evolution continued, and Darwin could not explain the source of the heritable variations which would be acted on by natural selection. Like Lamarck, he still thought that parents passed on adaptations acquired during their lifetimes, a theory which was subsequently dubbed Lamarckism. In the 1880s, August Weismann's experiments indicated that changes from use and disuse were not heritable, and Lamarckism gradually fell from favour. More significantly, Darwin could not account for how traits were passed down from generation to generation. In 1865 Gregor Mendel found that traits were inherited in a predictable manner. When Mendel's work was rediscovered in the 1900s, disagreements over the rate of evolution predicted by early geneticists and biometricians led to a rift between the Mendelian and Darwinian models of evolution.
Yet it was the rediscovery of Gregor Mendel's pioneering work on the fundamentals of genetics (of which Darwin and Wallace were unaware) by Hugo de Vries and others in the early 1900s that provided the impetus for a better understanding of how variation occurs in plant and animal traits. That variation is the main fuel used by natural selection to shape the wide variety of adaptive traits observed in organic life. Even though Hugo de Vries and other early geneticists rejected gradual natural selection, their rediscovery of and subsequent work on genetics eventually provided a solid basis on which the theory of evolution stood even more convincingly than when it was originally proposed.
The apparent contradiction between Darwin's theory of evolution by natural selection and Mendel's work was reconciled in the 1920s and 1930s by evolutionary biologists such as J.B.S. Haldane, Sewall Wright, and particularly Ronald Fisher, who set the foundations for the establishment of the field of population genetics. The end result was a combination of evolution by natural selection and Mendelian inheritance, the modern evolutionary synthesis. In the 1940s, the identification of DNA as the genetic material by Oswald Avery and colleagues and the subsequent publication of the structure of DNA by James Watson and Francis Crick in 1953, demonstrated the physical basis for inheritance. Since then, genetics and molecular biology have become core parts of evolutionary biology and have revolutionised the field of phylogenetics.
In its early history, evolutionary biology primarily drew in scientists from traditional taxonomically oriented disciplines, whose specialist training in particular organisms addressed general questions in evolution. As evolutionary biology expanded as an academic discipline, particularly after the development of the modern evolutionary synthesis, it began to draw more widely from the biological sciences. Currently the study of evolutionary biology involves scientists from fields as diverse as biochemistry, ecology, genetics and physiology, and evolutionary concepts are used in even more distant disciplines such as psychology, medicine, philosophy and computer science.
In the 21st century, current research in evolutionary biology deals with several areas where the modern evolutionary synthesis may need modification or extension, such as assessing the relative importance of various ideas on the unit of selection and evolvability and how to fully incorporate the findings of evolutionary developmental biology.
B. Darwin's evolution theory
Charles Darwin (1809-1882) has a long name of Charles Robert Darwin was the British scientist who discovered the country of origin research in the Galapagos Islands to support the theory of evolution. Charles Darwin called sebgai father of evolution because it has more complete data to strengthen the theory of evolution. Charles Darwin released two books that provide an important contribution to the development of the theory of evolution, namely: On the Origin of Species by means of natural selections - in 1859, The Descent of Man - 1857. Two main core of the theory of darwin: Species that live in the present comes from living things from the past and the evolution is due to the process of natural selection (natural selections).
C. Lamarck's theory
The definition and meaning of the definition of natural selection is the selection that occurs in individuals who live in nature, so that individuals can adjust to the environment will continue to live and breed, while those unable to adjust to the natural environment will be destroyed and lost eaten time.
Examples of events of natural selection is the peppered moth butterfly in the UK. Peppered moth butterflies there are two types, namely the winged bright sunny with a bersapap dark. Beginning english a clean environment is very good for the adaptation of the winged butterflies bright. However, due to industrial soot waste in the UK are more and more and pollute the trees so the trees became darker which eventually become more adaptive to the butterfly that wing dark than light. The result is increased development butterfly dark winged sharp and bright wings reduced drastically. Equation lamarck with tori darwin’s theory is equally evolisi occur due to the influence of environmental factors. While the difference is in that cause changes in living things, in which Lamarck quantity caused by the use of organs, while Darwin on natural selection.
D. The characteristics of the evolutionary process
1. Evolution is a change in one population is NOT a change in the individual.
2. Changes that occur only the frequency of certain genes, while most genes have not changed.
3. Evolution requires genetic drift as raw materials. In other words there must be a genetic change in evolution.
4. In the evolutionary changes driven by the environment, there must be a steering factor so evolution is the change in the selective.
E. Factor change
1. Gene mutation and chromosome mutation produces raw material for evolution. But Darwin himself was not familiar with this mutation, while mutation is a very important event that supports the validity of Darwin's theory
2. Recombination changes known Darwin. Recombination of the results of the realistic mutation raw material for evolution.
F. Steering factors
1. In each species there are many irregularities that decrease, thus in one species no two individuals are exactly the same in their genetic composition (at the instance of twins, the genetic composition remains the same).
2. In general, the reproductive process could increase the number of individuals in each generation more than the number of individuals in previous generations.
3. The addition of individuals in each species was driven up to the amount of a species population in a long time is not increased drastically.
4. There is competition between individuals within species to obtain their daily needs from their environment. Intra-species competition occurs between individuals of different genetic nature. Individuals who have the properties best suited to their environment will have a high viability. In addition to viability is also a high fertility is an important factor in natural selection.
G. The mechanism of evolution
The mechanism of evolution is due to genetic variation and natural selection. Genetic variation arising from: mutation and recombination of genes in the new offspring. Gene Frequency In the process of evolution of gene frequency changes. When comparisons between genotp-genotp in one population does not change from generation to generation, then the gene frequency in the population in a state of balance. Balanced gene frequency when: No mutation or mutations walk balanced (if gene A gene mutates into a, then there must be a gene which gene A in the same amount, no selection, no migration, random mating, large population.
H. Evidence of evolution
1. Homologue to be organs of living creatures that have the same forms, which later changed its structure so that its function is different. Example: Member of the lizards to walk forward, while the bird to fly, bird wings and bat wings, the front legs of horses and human hands. Analogue is the organs that have a shape different forms, but the same function. Examples: insect wings and bird wings.
2. The fossil record, fossils found in layers in proving that the organism was long before the present. Yag transitional fossils linking past and present, whales have ancestors who came from the mainland. Excavation leg bones and fossils show bacilosaurus (ancestors of whales) and Ambulocetus derived from an amphibious animal ynag have a leg bone that is used to move on land and in water.
3. Rudimentation organs, there is a very useful organ in an organism, it does not work on other organisms. Example: tail bone in humans, the appendix in humans and horses standing on his middle finger, while the other fingers are experiencing rudimentasi process in line with the evolutionary process.









CHAPTER III
CONCLUSION AND SUGGESTION

A. Conclusion
The mechanisms of evolution continued, and Darwin could not explain the source of the heritable variations which would be acted on by natural selection. Like Lamarck, he still thought that parents passed on adaptations acquired during their lifetimes, a theory which was subsequently dubbed Lamarckism. In the 1880s, August Weismann's experiments indicated that changes from use and disuse were not heritable, and Lamarckism gradually fell from favour.
B. Suggestion
The human know and understand the process iof evolution.