What is the process by which new species arise from existing species?

The process by which new species arise from existing species is known as speciation. This occurs when populations of a single ancestral species accumulate differences over time, often due to isolation or different environmental pressures. As these populations adapt to their respective environments and diverge genetically, they can eventually become distinct enough to be classified as separate species.

For example, speciation can happen through mechanisms such as geographic isolation, where physical barriers like mountains or rivers prevent gene flow between populations. Over time, the genetic differences that accumulate can lead to reproductive isolation, meaning that individuals from the diverging populations can no longer interbreed successfully, solidifying their status as independent species.

In contrast, evolutionary adaptation refers to the broader process of changes within a population that enhance survival or reproduction in a specific environment but does not necessarily lead to the formation of a new species. Extinction involves the complete disappearance of a species and is not a mechanism for creating new species. Natural selection is the process by which certain traits become more or less common in a population, but it is one of the driving forces behind speciation rather than the process itself.