In biological evolution, what is a key factor that contributes to the formation of distinct species?

The formation of distinct species, often referred to as speciation, is influenced by multiple factors, and the correct answer encompasses those diverse influences. Geographical isolation plays a crucial role in speciation by physically separating populations of a species, preventing interbreeding and allowing them to evolve independently. This leads to the accumulation of genetic differences due to natural selection and genetic drift, ultimately resulting in the emergence of new species.

Genetic drift is another significant factor; it refers to random changes in allele frequencies within a population. This can have profound effects in small populations where chance events may lead to certain traits becoming more common or rare, contributing to differences that can lead to speciation over time.

Natural selection acts on the variation within populations, favoring traits that enhance survival and reproduction in specific environments. This differential survival can lead to adaptations that further differentiate populations, paving the way for the development of distinct species.

Since all these processes—geographical isolation, genetic drift, and natural selection—play vital roles in the formation of species, the option that includes all of them highlights the multifaceted nature of evolutionary change. Each factor contributes in its own way to the complex dynamics that drive speciation.