Final answer:
Natural selection is the process by which organisms with inherited traits best suited to their environment are more likely to survive and reproduce, leading to evolutionary change over generations. The principles are inherited variation, overproduction of offspring, and survival competition, as only the advantageous traits are likely to be passed on.
Step-by-step explanation:
Natural selection is a critical concept within evolution that was first articulated by Charles Darwin and Alfred Russel Wallace. It operates based on three fundamental principles: inherited variation, overproduction of offspring, and competition among individuals for limited resources. Organisms inherit their traits from their parents, but due to genetic variation, offspring have different sets of traits from each other. As more offspring are produced than can survive, those with the most advantageous traits for their environment are more likely to survive, reproduce, and thus pass on those traits, leading to changes in population dynamics over time. This process is known as descent with modification, where the frequency of advantageous traits increases within the population, leading to evolutionary changes.
The mechanism of adaptation through natural selection is limited by the existing genetic variation in a population. It selects from what is available through mutations or new alleles introduced by gene flow. Over generations, this can result in populations that are better equipped to thrive and reproduce in their specific environments.