What process involves the development of new species from preexisting species?

The process that involves the development of new species from preexisting species is best described by the term "speciation." Speciation is a fundamental concept in evolutionary biology and refers to the process through which populations evolve to become distinct species. This often occurs due to genetic divergence, where populations experience different environmental pressures, mutations, and selective pressures over time, leading to reproductive isolation and the formation of new species.

While evolution is the broader overarching process that describes the change in the heritable characteristics of biological populations over successive generations, it encompasses various mechanisms, including speciation. Natural selection is one of the key processes that can drive evolution, but it specifically refers to the differential survival and reproduction of individuals due to variations in their traits. Adaptation relates to the process through which organisms become better suited to their environments, often as a result of natural selection, but it does not specifically denote the formation of new species. Thus, speciation is the term that accurately captures the transition from preexisting species to new, distinct species.