incipient species

Incipient species are natural populations that are somewhat interfertile with related populations but are prevented from interbreeding in nature by specific barriers. This concept is part of the broader study of speciation, which is the evolutionary process by which new biological species arise.123

Speciation can occur through gradual genetic divergence between populations, potentially leading to reproductive isolation. This isolation can be a byproduct of adaptation to different environments or directly promoted by natural selection when hybrids are less fit. When gene flow between populations is interrupted, they can become genetically distinct. If opportunities for hybridization arise, natural selection may favor traits that prevent interbreeding, thus completing the speciation process. Incipient species represent an early stage in this process, where reproductive isolation is not yet complete.24