Evolution as resistance to entropy. II. A conservative role for the sexual reproduction
V. P. Shcherbakov
Institute of Problems of Chemical Physics RAS, 142432 Chernogolovka, Moscow Region, Russia
A viewpoint is substantiated that a biological meaning of the sex and meiotic genetic recombination is a creation of a barrier for evolution. The transition to sexuality is not merely change of a mode of reproduction but it is an ascend to a new quality known as cohesion. In a sexual population, the lineages of different individuals get tangled into multidimensional net, a common gene pool of population is created, and a new superindividual entity, biological species, emerges. A sexual individual can not reproduce its particular genocopy and its fitness is sacrificed to some extent for the fitness of the species. A competition between the individuals is changed, in essence, for competition between gene alleles given that the competitors have after all the common offsprings. The genotypes of the “outstanding” individuals with a highest fitness are not transmitted to the next generation, being scattered and shuffled in new combinations after unavoidable crossing with the “ordinary” partners. So, the sexual population can evolve only as a whole. Genetic recombination in meiosis changes a form of the mutation distribution among gametes enhancing the classes with a mutation load both lower and higher than the average. By this, an efficiency of the truncated selection (elimination of the individuals with multiple mutations) is enhanced and an ability to restore the initial genotype appears. Evolution within the species becomes reversible, which is equivalent to its virtual cessation. The species acquires an evolution resistance that can be overcome only by rare concurrency of circumstances.
