The process by which organisms develop resistance to pesticides or antibiotics is known as selective pressure leading to evolutionary adaptation. When a population is exposed to these chemicals, individuals with genetic variations that confer resistance are more likely to survive and reproduce. Over time, the prevalence of resistant traits increases within the population, diminishing the effectiveness of the pesticides or antibiotics. This phenomenon underscores the importance of responsible use of these substances in agriculture and medicine to prevent the development of superbugs and resistant pests.