Explain the evolutionary mechanisms that can change the composition of Essay

Explain the evolutionary mechanisms that can change the composition of the gene pool - Essay Example In addition, certain evolutionary processes such as natural selection and genetic drift cause a decrease in these genetic variations (Colby; Lerner). Mutation is a phenomenon by which chemical changes occur within the DNA which in turn alters the sequence of the gene resulting in a mutant gene. The extent to which the DNA is altered depends on the type of mutation which could be a point mutation in which on letter of the genetic code is changed, insertion or deletion of a stretch of DNA within a gene or inversion, translocation or duplication of a segment of the DNA. Such mutations can produce truncated proteins, abnormal proteins or a silent mutation that does not introduce any change in the resulting protein. Hence a mutation can have both a deleterious as well as a beneficial effect on the organism (Colby; Lerner). In addition to mutation, gene expression within an organism also depends on the built-in natural variation that occurs within a gene pool. Not all genes within an organ ism are expressed as only those which are activated produce their respective proteins and are hence expressed in the phenotype. Such selective expression of genes is also responsible for the variations observed between each individual (Veith).