Darwins Theory of Evolution - Essay Example

Evolution questions Darwin’s theory of evolution explains the relationship of species and that they descended from a common ancestor. He argues that the species are related and asserts that the birds and the bananas, the fishes and the flowers have are related. The idea passed on by Darwin is that, the species developed from ancestors naturally over time. Darwin was inspired by the birds while he was travelling to Galapagos Islands. He was on a navy when he saw species that were not present in any other place, but he said that they were similar one in other parts like west Coast of South America. He was interested by the fact that the species were different. He concluded that the species were different because they dwelled in different environments The concept of natural selection explains how species evolves and genes are passed from generation to the next. Darwin argues that a species can develop a functional advantage in that the species grows wing and learn to fly. He asserts that the offspring will inherit that advantage and pass it on to the offsprings. On the other hand, those who are disadvantaged but members of the same species will gradually die and live the superior members of the same species. Species preserve the functional advantage and that help the species to compete in the harsh environment. Darwin’s explanation of the origin of species in 1859 was criticized by Christians because they believed in God’s creation for six days. The natural selection was received with hostility because his ideas were not with alignment with biblical descriptions on how Adam and Eve were created. In addition, after the arrival of Darwin’s theory, scientists conflicted and they did not support the idea of evolution. A vector is a vehicle that transfers genetic materials to a target cell. The significance of vectors is to pass on the genes to the intended cell. For evolution to take place there has to be passage of genetic materials from one species to the other. Hence the vector facilitates the movement of biological traits from one generation to the other. Equilibrium is a principle that explains that genes remain the same from one generation to the other without any disturbing factor. If the situation remains constant then there will be evolution stability. However this can be affected by forces such as mutations, natural selection, non random mating, genetic drift and gene flow. Micro evolution can be defined as the change in genes for the species for a short period of time resulting to alterations of successful reproducing individuals within a population. Species are differentiated by the physical characteristics. For instance, some species are tall other short. Darwin also gives an example of the birds that had and different sizes of beak. Isolation can promote genetic divergence through mechanisms such as mutation, genetic drift and natural selection. Allopathic speciation is a phenomenon used whereby formations of new species occur in isolated geographical areas. Populations can become isolated thro dispersal and colonization. When these populations are isolated they undergo changes in mutation and selection due to change of environment and gradually change the genetic substitutions and eventually become genetically differentiated. This leads to different morphological and psychological differences. Genetic drift on the other hand, changes in the environment lead to change in population. People can be isolated by changes in the geographical arrangement for instance when a road is constructed, the species can be isolated. Natural resources such as lakes and oceans may separate people and therefore, the genes are not passed on. Fossils are past remains of human bodies such as skeletons and teeth. The fossils help people understand various things in human species. They help in explaining the quick growth of early human species, the difference between the male and female body size and adaptation to different environments. Fossils show that family trees have many branches and deeper roots. Fossils can be used to trace the origin of a species and even when there if continental movement, the fossil records can help find out where the species originated from. According to Ken Harding, the two major forces that drive the evolutionary process are birth and death (Ken Harding). Human activities can lead to species extinctions for instance the commercial fishing which leads to emptiness of the ocean. The rising temperatures in the oceans also lead to death of the planktons or failure to reproduce and therefore the species becomes extinct. In modern society the farmers over cultivate, and the soil erosion destroys the micro ecosystem that exists on the top soil. When one species is extinct the surviving species may be put in danger and eventually may die. For instance, in the oceans when the plankton die due to high temperatures, the fish cannot survive because the lack food. When there is over cultivation and soil erosion the surviving species are affected because they lack nutrients to grow in a healthy manner. During the Paleozoic and Mesozoic era, there are gaps in the fossil record due to lack of empirical evidence of evolution of mammals. During the Mesozoic era reptiles were dominant but at the end of the era the dinosaurs were becoming extinct. The disappearance of dinosaurs stimulated the evolution of mammals. Millers experiment was aimed at showing the way amino acids can form over the years. His results were received with great joy because evolution had faced a lot of criticism. Scientists came together and they produced new scenarios like discovery of proteins. Oxygen is crucial for species to exist. Around three and a half billion years ago, the atmosphere was anoxic. Oxygen was absent and this is believed to have been important for the synthesis of organic material from inorganic chemicals. There was therefore the absence of an ozone layer and this facilitated the high energy radiation blast from cosmos to reach the earth and ocean surfaces uninterrupted. This cosmic energy was important in transfer of materials from inorganic to organic. This was important for evolution. The comparative biochemistry help to establish the lineage of the primordial organisms in that the similarity of species can be traced through the nutrients found in that species such as DNA. We are similar to single- celled organisms in that they move. The movement is evident and cells move is seen in both human and organisms. Human cells move in their normal cells and in diseases such as arthritis, asthma and cancer. Work cited Charles Darwin, "On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life," 1859, p. 162. “Origin of the Life- Different theories and Prepositions: AL Islam, 18 Nov, 2011 http://www.alislam.org/library/books/revelation/part_5_section_2.html Read More