Understanding evolution helps us solve biological problems that impact our lives. There are excellent examples of this in the field of medicine. To stay one step ahead of pathogenic diseases, researchers must understand the evolutionary patterns of disease-causing organisms. To control hereditary diseases in people, researchers study the evolutionary histories of the disease-causing genes. In these ways, knowledge of evolution can improve the quality of human life. Evolution played an important role not only for the present day humans but all living things today. As you all know, we didn’t just evolve out of nothing, we all have an ancestor whose ancestor’s ancestor is our ancestor and so on. When we can’t go back any further because of the given facts, we know that was every organism’s common ancestor.
To understand the importance of evolution, we must gather some understanding of the meaning of evolution. Here is biological evolution defined by one of the most respected evolutionary biologists, Douglas Futuyma.
"In the broadest sense, evolution is merely change, and so is all-pervasive; galaxies, languages, and political systems all evolve. Biological evolution ... is change in the properties of populations of organisms that transcend the lifetime of a single individual. The ontogeny of an individual is not considered evolution; individual organisms do not evolve. The changes in populations that are considered evolutionary are those that are inheritable via the genetic material from one generation to the next. Biological evolution may be slight or substantial; it embraces everything from slight changes in the proportion of different alleles within a population (such as those determining blood types) to the successive alterations that led from the earliest protoorganism to snails, bees, giraffes, and dandelions." - Douglas J. Futuyma in Evolutionary Biology, Sinauer Associates 1986
In short, biological evolution refers to populations and not to individuals and that the changes must be passed on to the next generation. Though evolution itself means a process that results in heritable changes in a population spread over many generations.
The gene pool of a population of organisms can change by mutations and/or by natural selection. Mutations add new genes to the gene pool and natural selection removes genes. Changes in the gene pool to create a new species can either be beneficial or a disadvantage. Usually when it is a disadvantage, the organisms will be easy prey or it will make it hard for the organism to catch food for its survival and usually the disadvantaged species will eventually die out. Without evolution, organisms will be disadvantaged with the constant change in the environment. So without evolution, every organism will die out eventually. Therefore, evolution played an important role for the survival for each species in today’s society.
In his famous book called The Origin of Species, published in 1859, Charles Darwin suggested that natural selection was the process in which species change over time and develop into new species. This process is now called evolution.
He was the first person to argue that the process of natural selection or ‘survival of the fittest’ brought about the change. Since there was not much knowledge about genetics, Darwin and other scientist could not explain the cause of the variations and the way they are inherited. Though today, scientists have a better understanding of genetics and as more and more discoveries are made, more theories emerge from scientists. Though theories develop as inferences they are suggested and evidence is collected to support or dispute them. This is why theories are likely to change. In the future, new fossil discoveries and advancements in technology will undoubtedly change some of the ides that form the current theory of evolution.