Darwinism (Essay Sample)

Name:
Lecturer:
Subject:
Due date:
Darwinism
Darwinism originates from the works of Charles Darwin, a biologist who proposed that contrary to popular beliefs, human beings are not a creation of a superior being (The Modern Synthesis of Genetics and Evolution). Rather, he is the product of thousands of years of evolution. People tend to narrow evolution down to ape like origins, however, it is much more complex that that. Human beings, along with all living things started out as unicellular organisms. Through sexual reproduction, we have evolved to the different and complex organism that we are in the current day. Darwin’s book, the origin of species by means of natural selection, was instrumental in making the best case for evolution The Modern (Synthesis of Genetics and Evolution). However, he build a case without prior knowledge of genetics, whish forms the biggest biological criticism to his theory. In the modern day, evolution in biology is accepted as the source of human life. However, the debates revolve around the mechanism of natural selection.
The main criticism to Darwin’s theory of evolution originated from the church. It was unacceptable to that human beings originated from apes. The theory was subject to a lot of criticism and hostility in the first years following its introduction. Most notable is a priest that asked Darwin if his farther was an ape. Darwin himself was a believer and only published his works after there were threats of someone else taking credit. There are numerous accounts of ridicule directed at him, including drawings of cartoons with Darwin’s face and the body of an ape.
However, respite came from the works of the famous archeologist Richard leaky and his family in Africa. They discovered fossils of what is thought t be remains of the early man. These fossils were preserved by volcanic ash and clearly implied that the early man did not walk upright like the modern man. Biologists have also proven that evolution is a continuous process but its effect takes millions of years to manifest. When two organisms mate, their offspring caries mixed genes and this mixture and modification eventually leads to change. Abnormal chromosomes also contribute to the process.
There are many theories that originated from the original Darwin arguments. They include reduction view, natural selection adaptations, gene selection, modern synthesis and altruism. They are all related to evolution. For instance, according to Darwin, the evolution of animals follows natural selection. Animals unable to adapt to their surrounding become extinct. It is survival for the fittest. The theory suggests that extinction results from nature selection against a species, for example the dinosaurs.
Natural selection is more or less o synonym of survival for the fittest. Due to modifications of the natural environment, species were forced to adopt to survive. There have been huge changes of weather patterns and vegetation over the years. Land that was once productive and easy to live in turned to unforgiving deserts with little to support life. Over many years, these changes led to corresponding changes in animals. According to Lamarck’s theory of use and disuse, using a particular organ leads to development of that organ. In this regard, when giraffes had to feed on treetops, they stretched their necks, leading to elongation of the organs. Over the years, giraffes that were not able to adopt became extinct, what remained are the current animals with ling necks and legs. The theory offers an explanation why nature is so perfect, imperfections are selected for extinction, leaving the best candidates for survival.
However, Lamarck’s theory does not correspond to genetics theory. A modification in one animal does not alter their genetic composition, and there fore the trait cannot be passed on to off springs, meaning that genetic composition is a constant from birth, stretching does not alter that. The theory also lacks sufficient biological proof, because the process takes millions of years and is therefore not documented. In addition, an animal can simply migrate to and are where the conditions favor its strengths. Such a migration implies that deserts are for animals with the best survival skills and plants most adapted to survival with little water.
Adaptation and natural selection go hand in hand. Species change to adapt to changes in their environment. This change is what is called adaptation (Vinicius 32). All species are adapted to life in their environment and they are therefore in perfect harmony with the environment. Before the rise of the modern technology, it was not possible to modify the environment. The environment modified the species in it. Failure to modify led to extinction. However, the theory of adaptation has several limitations, such as the rise of man. Man is superior to his environment, particularly in the modern age. He has the ability to change the environment to change and suit his life style, the best examples are the cities if Dubai and Las Vegas. They are located id deserts but they have better water supply that most places located in much better places. Israel is one of the leading exporters of horticultural products, yet the country is a desert. However, before the rise of the modern period, there was environmental determinist. Evidence is the differences in the physical characteristics of man. The people who live in the Kalahari Desert need little water to survive, other people who go to those places face a risk of dehydration, yet they have similar genetic composition (Vinicius 132). People who are from highland have a better capillary network in their lungs to make use of the thin supply of oxygen in high altitude. Therefore, before the onset of the modern period, there is proof that even man had to adopt to survive. The adaptations of man are not natural and they pose a threat to survival of other species. Scientist estimates are that there are more extinctions and endangered species presently than during any period in time.
Modern synthesis is a theory that attempt to explain how evolution works at the level of the genes (Borrello 209). Darwin was unable to comprehend this because at his time, there was no knowledge of genes and their workings. The theory of modern synthesis holds the view that evolution is a result of small mutations, which are incorporated and transferred from parents to off springs. Evolution occurs through gradualism and punctuated equilibrium, depending on genetic variance. Abrupt mutations lead to short periods of mutation and vise versa. Evolution is therefore a result of many mutations and variances within a population result from differences in genetic composition and make up. The theory clearly explains the mechanisms of evolution in a ...