What process describes the survival and reproduction of the fittest?

Natural selection is the process that describes the survival and reproduction of the fittest. This concept, first articulated by Charles Darwin, suggests that individuals with traits better suited to their environment are more likely to survive and reproduce, passing those beneficial traits to the next generation. Over time, this leads to the evolution of species as advantageous traits become more common within a population.

This process is driven by various factors, including environmental pressures and genetic variation within a population. The most fit individuals are those that successfully adapt to their environment, which can involve finding food, avoiding predators, or attracting mates. The "fittest" does not necessarily refer to the strongest or fastest but rather to those organisms that are best suited to thrive under specific environmental conditions.

The other terms relate to different mechanisms of selection within the framework of evolution. Stabilizing selection favors intermediate phenotypes, thus reducing variation. Directional selection shifts the frequency of traits in one direction, often in response to changing environmental conditions. Disruptive selection favors extreme traits and can lead to speciation, but does not encompass the broader concept of the survival and reproduction of the fittest as natural selection does.