Evolution Case

Evolution is the name of a theory that explains the change in living organisms and variation within species or organisms. Evolution is a process in which the characteristics of living organisms change over many generations while the traits are passed on from one generation to the next. Charles Darwin, who was considered the father of evolution, had discovered the origin of the species and the process of ongoing history of life on earth. Long before the rise of modern science in Western Europe in the 17th and 18th centuries, a powerful view had came upon, that God had created every organism on earth. But the study of natural history and fossils had became popular, and in the connection with it, the beginnings of an evolutionary theory had began to take shape. Early evolutionary theorists had proposed that all of the life on earth evolved gradually from simple organisms, but their knowledge of science was incomplete; therefore, their theories left many questions unanswered. Most well-known scientists remain convinced that the variety of life on earth could only result from an act of divine creation. Evolution is a process through which the traits are passed on and along with that chromosomes are passed, but with a genetic drift the amount of chromosomes affects the rate of evolution.

In the mid 19th century, Charles Darwin, a British scientist, had founded the modern evolutionary theory with his concept that all forms of life evolve and change through the process of natural selection. His work was a major influence on the life and earth sciences and on modern thought in general. Darwin's theory of evolution is divided into 5 different parts: natural selection, mutation, genetic drift, gene flow, and speciation. Natural selection is a process in which the environmental effects lead to the changing degrees of reproductive success among individuals of a population of organisms with different hereditary characters or traits. Natural selection, in is the " survival of the fittest"; the strong will survive, the weak will die. A mutation is a process in which genes themselves are constantly being modified or a change that occurs in the structure of the DNA in an individual's cells. Mutation occurs during replication, or the process in which a cell splits into two identical copies, known as "daughter cells." Each daughter cell receives an exact copy of the DNA from the parent cell. However, errors may occur, resulting in a change in gene structure; this change may affect the protein that the gene produces and ultimately changes an individual's traits; mutation is a permanent change.

In 1858, Charles Darwin had introduced the Genetic drift which can cause a form of gene in a population which leads the allele to have a greater evolutionary fitness. The form of a gene causes evolutionary fitness which is the probability that the line of the common ancestor or the descent will not die out. In the contrast, a genetic drift can also cause an allele to become fixed in a population; through which the allele can be found in every member of the population, which causes the allele to decreases fitness. Genetic drift is known as an isolation change which proves that a decrease in a chromosome or an increase in the number of the chromosomes does affect the rate of evolution. Gene flow occurs when individuals move from one population to another, and new genes may be introduced to new populations. This results in the chance of dispersal and intentional migration. For example, two populations of related flowers, one white and one pink, were separated by a large stretch of land. The two groups do not interbreed because the wind does not blow hard enough to carry pollen between the populations. If one day, a very strong wind carried pollen from the white flower population to the pink flowers population, the gene for white flowers could be introduced to the pink flowers population's gene pool. Therefore, interbreeding takes place. Speciation occurs when a barrier, for instance a stretch of sea or a mountain range, separates different populations of a particular species; the populations can no longer cross the barrier to interbreed. This allows only natural selection or genetic drift to produce distinctive gene pools.

The long journey of human evolution begins with the characteristics of mammals. Sixty-five to fifty-five million years ago were when these small, insignificant animals made their appearance on earth; during a time period called "Paleocene epoch." Monkeys, apes, and humans belong to the 'primates' category which appeared during the "Eocene epoch" time (55 to 50 million years ago). They eventually developed larger more complex brains, sense organs, limbs, and reproductive systems. These early apes are called prosimians. Living in the forest prepared them to adapt to the environment in which they would