What mechanism drives changes in a population's gene pool over generations?

The mechanism that drives changes in a population's gene pool over generations involves several interconnected processes, including mutation, adaptation, and natural selection.

Mutation introduces new genetic variations into a population by altering DNA sequences. These variations can create new traits that may be beneficial, neutral, or detrimental to the organism's survival and reproduction. This influx of new alleles can result in shifts in the gene pool.

Adaptation refers to the process by which organisms become better suited to their environment. As individuals with advantageous traits are more likely to survive and reproduce, these traits become more common in subsequent generations, leading to a change in the population's gene pool. Adaptation is heavily influenced by the variations introduced through mutation.

Natural selection acts on the existing genetic variations within a population. It is a differential survival and reproduction mechanism where individuals with favorable traits are more likely to thrive and pass those traits on to their offspring. Over time, natural selection can lead to significant shifts in the frequency of alleles within the gene pool, shaping the evolutionary path of a species.

Since all these mechanisms contribute to changes in a population's gene pool, the correct answer encompasses the entirety of these processes. Each plays a vital role in the ongoing evolution of species over generations.