The process of forming a new species is called speciation. Speciation occurs when a population becomes isolated due to geographical, ecological, or behavioral barriers, leading to genetic divergence over time. This process can occur through various mechanisms, including allopatric speciation, where populations are separated by physical barriers, or sympatric speciation, which occurs without geographical separation. Ultimately, when the accumulated changes prevent interbreeding, a new species emerges, contributing to biodiversity.