While individuals of different populations within the species can occasionally interbreed in nature and give rise to prolific offspring, i.e. as long as there is a hint of genetic information between populations, the species remains a holistic and unified system. However, as a result of strong isolation pressure, the gene flow can be interrupted and isolated populations, having accumulated changes under the influence of always acting elementary evolutionary factors, may cease to interbreed in subsequent encounters. The emergence of reproductive isolation between different populations means the division of one species into two, i.e. the process of speciation. Therefore, the question of how new species are formed is identical to the question of how reproductive isolation arises between populations within a species.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.