According to an online dictionary source, natural selection is defined as the process by which forms of life having traits that better enable them to adapt to specific environmental pressures, as predators, changes in climate, or competition for food to mates will tend to survive and reproduce in greater numbers than others of their kind, this ensuring the perpetuation of those favorable traits in succeeding generations. A simpler definition of this could be a phrase that we hear most often, “survival of the fittest”. Natural selection usually occurs by chance and at a slow,steady rate. However, humans are responsible for constantly changing the environment. So overall I do not believe that because of this rapid change, natural selection can work according to this rate. Therefore, a large percentage of animals may not be able to survive its environment and as a result of this there may be less variation in species.