Sympatric speciation: compliance with phenotype diversification from a single genotype

A novel mechanism for sympatric speciation that takes into account complex bioprocesses within each individual organism is proposed. According to dyna mical systems theory, organisms with identical genotypes can possess differ entiated physiological states and may coexist 'symbiotically' through appro priate mutual interaction. With mutations, the phenotypically differentiate d organisms gradually come to possess distinct genotypes while maintaining their symbiotic relationship. This symbiotic speciation is robust against s exual recombination, because offspring of mixed parentage with intermediate genotypes are less fit than their parents. This leads to sterility of the hybrid. Accordingly, a basis for mating preference also arises.