Sex in Plants and Factors in Sexual Differentiation

Abstract

The evolution of the plant and animal worlds led to the evolution of the means of reproduction. Sexual reproduction became the most progressive form of reproduction in the organic world. The significance of the sexual process in phylogenesis resides in the fact that fertilization leads to an organism with dual heredity, which in turn ensures greater stability and adaptability to the constantly changing conditions of life. Herskowitz (1965) pointed out that even if reproduction were only asexual, the earth would still be populated by genetically distinct organisms. Each variant would arise as a result of a mutation in the ontogenesis of the previous individual, which in turn would have arisen from an uninterrupted line of generations. However, such a direct inheritance is of limited effectiveness, because it relies on the occurrence of rare mutations. Compared with asexual reproduction, the development of sexual processes offered immense genetic advantages, as obligatory genetic recombination greatly accelerated the rate of evolution.