University of Central Florida (UCF) BSC1005 Biological Principles Practice Exam 2

Genetic drift is a mechanism of evolution that occurs due to random events that can lead to changes in allele frequencies within a population. This randomness can manifest in various ways, such as through environmental disasters, diseases, or other unpredictable occurrences that affect individuals in a population regardless of their fitness or adaptive traits.

Because genetic drift is a non-selective process, it affects all individuals within a population by chance rather than by their survival or reproductive success. Over time, this can lead to significant shifts in genetic diversity, especially in small populations, where random effects can have a more pronounced impact compared to larger populations where allele frequencies are more stable due to the law of large numbers.

In contrast, options related to consistent improvements in fitness, deliberate selective breeding, and natural selection pressures involve mechanisms that are dependent on the advantages conferred by specific traits or behaviors, thereby influencing allele frequencies in a more directed manner rather than randomly.