Which type of natural selection can lead to the development of two or more distinct species?

Disruptive natural selection occurs when individuals at both extremes of a phenotypic spectrum have higher fitness than those with intermediate phenotypes. This type of selection can lead to speciation because it favors divergent traits within a population, creating two or more distinct groups that may ultimately evolve into separate species.

For example, in a hypothetical environment with two different types of food sources, individuals that can specialize in either food type may thrive, while those that have traits suited for both may struggle. Over time, as these groups adapt to their specific niches, they may become reproductively isolated from each other, thus promoting the process of speciation.

Stabilising natural selection tends to maintain the status quo by favoring average traits, which minimizes variation and does not encourage the formation of distinct species. Directional natural selection drives a population towards one extreme of a trait, which can lead to changes within a single species but does not necessarily result in the formation of multiple species. Artificial selection involves human intervention in breeding practices and does not occur naturally in wild populations.

Therefore, disruptive natural selection is the mechanism most directly associated with the emergence of distinct species through the promotion of divergent traits within a population.