The lack of resources needed for survival causes competition amongst the individuals as they compete for food and the necessities. An example of the environment constraining population growth can be found during a severe drought that occurred in 1976 that affected the seed availability and quality for the birds in that area. The natural instinct of the birds were to strive for better access to these seed resources however many birds died from starvation. The second postulates states that organisms vary in their physical qualities and these variations allow some members to reproduce more successfully than others. In a given bird population, one will notice differences of phenotype traits that alter from their physical appearance of beak size and these diverse looks allows for more adaptive qualities in that environment as reproduction occurs. For example, during the drought the bigger sized beak had more of an advantage compared to the smaller beaked size for their traits allowed for better access to the seeds available. Lastly, the final statement follows that these variations are inherited by offspring from their parents. Biologically, the passing down of these variations are hereditary from the parents of …show more content…
Competition is one factor that influences evolution because as the environment restricts the resources available for the organisms, the animals find it harder to survive. Therefore, they compete with other members in that biome for better access to these resources that promise survival. The act of competing for quality resources is helping the population evolve for natural selection is selecting certain traits that have helped ensure better survival ability. Another role natural selection plays in evolution is through adaptation which is defined to as highly favorable traits that will eventually become widespread in the population, building new species-typical features. An example of this can be found in the animal kingdom more specifically polar bears. Polar bears live in Antarctica and through the process of natural selection they have adapted the trait of thick fur coat that has the benefits of keeping them warm. Lastly, natural selection plays the role of variation in evolution which is defined as in all species, individuals vary in some of their physical or behavioral characteristics. For example, in a population of butterflies, each individual butterfly is unique to its appearance of color and shapes. Natural selection is acting upon these varied characteristics that are are present within the population