How do selection pressures affect genetic diversity?

Selection pressures can significantly impact genetic diversity within a population. When certain traits offer a survival or reproductive advantage in a specific environment, individuals displaying those traits are more likely to survive and pass those traits onto their offspring. This process, known as natural selection, can lead to a decrease in genetic diversity over time.

As specific traits become more common due to selection pressures, the alleles associated with those traits proliferate, while other alleles may diminish or disappear entirely from the gene pool. This results in a population that is less genetically diverse, as fewer variations or mutations are represented. Over time, this can make populations more vulnerable to changes in the environment or disease, as a lack of genetic diversity can limit the adaptive potential of the population.

In contrast, selection pressures do not typically increase genetic diversity, nor do they allow for more mutations to arise, as mutations occur randomly and are not directly influenced by observable traits within a population impacted by selection. Additionally, it is inaccurate to claim that selection pressures have no effect on genetic diversity; they are a decisive factor in shaping the genetic makeup of populations.