Humber Admissions Practice Test

Which of the following is a primary factor in the process of natural selection?

1. Genetic variation within a species

2. Increased reproduction rates due to human intervention

3. Aquatic environment adaptation

4. Symbiotic relationships between species

The correct answer is: Genetic variation within a species

Genetic variation within a species is a primary factor in the process of natural selection because it provides the raw material for evolution. Without genetic diversity, all individuals in a population would be very similar, making the entire group susceptible to the same diseases, environmental changes, and other survival challenges. Natural selection operates on the principle that individuals with traits that are advantageous in their environment are more likely to survive and reproduce, passing those favorable traits to the next generation. This variation is crucial as it allows some individuals to better adapt and thrive under specific conditions, leading to changes in the frequency of traits within a population over time. Other factors mentioned, like increased reproduction rates due to human intervention, aquatic environment adaptation, and symbiotic relationships between species, may influence the dynamics of evolution but are not the fundamental mechanisms of natural selection itself. They may facilitate or impact the process but do not serve as the primary driving force behind the selection of traits within a species.