Organisms of different generations exhibit numerous changes in their physiological and physical setups. The changes are attributed to the transformations that occur over the ages in the organism. The evolution theory explores various mechanisms that cause the transformations in the organisms over the years. Evolutionary changes are perceived to have occurred as a result of mechanisms that interfere with the normal structural orientation of a certain population. The evolution forces facilitate the formation of unique characteristics in certain groups of organizations in a population and thus leading to the formation of species. The forces of evolution include natural selection, genetic drift, mutation and migration.
Natural selection is described as a form of differential reproduction whereby organisms that have attributes that are well adapted to the environment have more chances of survival. The traits t that enhance the chances of survival are usually heritable. Therefore, the fit organisms can survive and reproduce the organisms of the next generation. As a result, they pass the survival genes to their offspring. These organisms can dominate the environment over the years because they have a greater chance of reproducing, and thus, this is the strategy that suppresses the existence of the other mechanisms in the population.
Mutations describe the occurrence of errors in the alleles that carry the genetic materials. The errors lead to changes in the nucleotide sequence of an organism. The DNA material is the one that carries the characteristics that are carried from the parents to the offspring. If the changes occur, the offspring is likely to have different characteristics from the parents. The changes that may occur as a result of an error in the members of the first generation may be transmitted to the members of the next generation, and thus, this is likely to cause changes over the generations.
Genetic drift relies on probability and chance to project that members of a certain population are likely to have more chances of survival than members than others. The drift can be as a result of a random change in the frequency of genes of certain organisms. The random change in the genetic material can lead to change of physiological and patterns of an organism. If the changes persist over and again, there is a big chance that the probability could be favoring the survival of members of a certain group. The changes that are caused by chance from generation to generation are likely to cause a genetic drift which is likely to cause a change in the demography of the population.
Migration is the movement of individuals into and out of a population. The movement of these individuals initiates the movement of phenotypes from one population to another. The migration can lead to the introduction of certain types of organisms in a population they did not exist. Their presence in a new environment can enhance their reproduction and thus increasing their numbers within the population. The ultimate effect of the migration is the increase in frequency of the new organisms in the population and thus changing the structural formation of the initial population.
The forces of evolution change the frequencies of the occurrence of certain genes in a population. The mechanisms also act along various forces like environmental influences to cause changes among the organisms. When the forces act for long periods, some organisms are likely to develop adaptive mechanisms that are passed to the next generations. Ultimately, the changes lead to the formation of new patterns within the populations resulting in speciation and isolation. The frequency of gene flow and transformation is also very critical towards forming the speciation.