In the context of evolutionary biology, what does natural selection refer to?

Natural selection is a fundamental mechanism of evolution, describing the process through which certain traits become more common in a population due to the survival and reproduction advantages they confer to individuals in their specific environments. It operates on the principle that individuals within a species exhibit variations in their traits, and these variations can impact their ability to survive and reproduce.

The concept aligns with the idea that organisms best suited to their environment tend to survive and reproduce at higher rates than those less suited. This selective pressure can lead to changes in the population over generations, as beneficial traits become more prevalent. This process helps explain the adaptation of species to their environments, resulting in increased fitness, which is a measure of reproductive success.

The other options describe processes related to biology but do not capture the specific mechanism of natural selection. Random changes in gene frequencies refer to genetic drift, the introduction of new species pertains to speciation, and mutations contribute to genetic variation, but they do not inherently drive the selection process that favors certain traits over others.