A complete understanding of evolution requires appreciation

A complete understanding of evolution requires appreciation of evolution as a process and as a pattern. Of the various well-known pieces of evidence for evolution, identify one that exemplifies the process of evolution. Explain your answer. Then identify and explain one piece of evidence that exemplifies the pattern of evolution.

Solution

Biological evolution is defined as a\" descent with modification,\" which includes both small scale and large scale evolutions. In small scale the changes occurs genetically within a population and from one generation to another. Whereas, in large scale evolutions there is one common ancestor which descents into different species.

The mechanism or the process of evolution involves the following things

Mutation: the ultimate source of genetic variation is mutation. It is change in gene or DNA sequence due to aberrations or changes like deletions, addition., Substitution etc.

Migration: movement of one gene from one population into other. It unifies the gene frequencies among the populations that are on urge of evolution. When there is absence of \'selection\' then migration acts as a strong force that equalizes the gene frequencies of subpopulation in a species.

Genetic drift: occurrence of gene variants increases or decreases over time. It effects significantly when a population is reduced in size due to natural calamity or disaster.

Natural selection: it comprises variation in traits, differential reproduction and heredity.

Example: mutations in pathogenic bacteria which we call multiple drug resistant bacteria or \" super bug.\" Bacteria have a wonderful tendency of mutation againsts antibiotics, which safeguards them from the effect of antibiotics. The genetic mutation in bacteria makes them more resistant to antibiotics.