Charles Darwin’s theory of evolution by natural selection is by far on of the best theories in the history of science. Many still do not believe in Darwin’s theory because they believe that a higher force (GOD) created every species for a specific environment. However, Darwin’s theory of evolution by natural selection is based on three easily verified observations: (1) Individuals within a species vary from one another in mophilogy, physiology, and behavior. (2) Variation is in some part heritable so that variant forms have offspring that resemble them. (3) Different variants leave different number of offspring. Charles Darwin’s theory of evolution by natural selection is important because his ideas were the first that made people aware of their place in evolution.
Three important points need to be emphasized about evolution through natural selection.
Although natural selection occurs through interactions between individual organisms and their environment, individuals do not evolve.
* A population (a group of interbreeding individuals of a single species that share a common geographic area) is the smallest group that can evolve. Evolutionary change is measured as changes in relative proportions of heritable traits in a population over successive generations.
* Natural selection can act only on heritable traits, traits that are passed from organisms to their offspring. Characteristics acquired by an organism during its lifetime may enhance its survival and reproductive success, but there is no evidence that such characteristics can be inherited by offspring.
* Environmental factors vary from place to place and from time to time. A trait that is favorable in one environment may be useless or even detrimental in another environment
Starting with the first verified observation, Darwin began to understand that every population has individuals that are slightly different from one another. Those individuals have a variation that gives them an advantage...