Which principle suggests that heritable traits enabling better survival and reproduction are more likely to be passed on?

The principle that heritable traits enabling better survival and reproduction are more likely to be passed on is referred to as natural selection. This concept, first proposed by Charles Darwin, posits that individuals within a population exhibit variations in their traits, and these variations can affect their ability to survive and reproduce in their environment. Traits that enhance an organism's fitness—meaning its ability to survive and produce viable offspring—are more likely to be inherited by the next generation. Over time, this leads to the prevalence of advantageous traits within a population.

In contrast, genetic variation refers to the diversity in gene frequencies within a population, which is essential for natural selection to occur but does not itself dictate which traits will be passed on. Mutation theory focuses on how mutations introduce new genetic variations but does not directly address the mechanism by which advantageous traits are selected for. Adaptive radiation describes the evolutionary process where organisms rapidly diversify to fill different ecological niches but again, this process relies on the principle of natural selection to drive the changes. Thus, natural selection is the key principle that explains how certain heritable traits become more prevalent in a population over generations.