quantum speciation

Quantum speciation, also known as rapid or saltational speciation, is a mode of speciation where the first stage occurs in a short period. It often leads to the formation of new species within the same geographic territory as the parent population, a process termed sympatric speciation.1

A significant form of quantum speciation is polyploidy, where an organism has more than two sets of chromosomes. Without polyploidy, quantum speciation can be initiated by chromosomal mutations, such as translocations, which can suddenly arise but may reduce the fertility of individuals carrying them. Self-fertilization in plants like Clarkia can help propagate these mutants. In animals, chromosomal mutations are often the starting point for quantum speciation, particularly in less mobile species like moles and rodents.1

Speciation can also be driven by changes in one or a few genes that alter an organism's ecological niche or, in the case of parasites, lead to a change in host preference. This can result in reproductive isolation if hybrids are less fit in either host environment. Genetic studies suggest that while the first stage of speciation involves substantial genetic change, the second stage, leading to reproductive isolation, often requires relatively few additional genetic alterations.12