Sister killers

A very interesting, although certainly not generally accepted hypothesis – see e.g. {11160}, which explains the absence of a mechanism  for the formation of haploid sex cells based on simple division of diploid cells into two haploid cells, assumes that the purpose of the present complicated mechanisms of nuclear division is to prevent the formation and spreading of hypothetical genes termed sister killers (Butcher & Deng 1994; Hurst 1993; Haig 1993a). If reduction of ploidy were to occur through simple division of diploid cells into two daughter cells, ideal conditions would be created for the formation and spreading of alleles that, following division of the diploid cells into two haploid cells, would program the haploid cell, in whose nuclei they would be present, to kill its sister haploid cell. The sister-killer allele would, at least initially, spread very rapidly in the population, as heterozygote diploid cells would produce only haploid sex cells with this allele. From the long-term viewpoint, such a system would be unstable as homozygotes with two copies of sister-killer alleles would not produce viable progeny. The allele would have to learn to recognize whether its copy is present in the sister cell and, on this basis, trigger or not trigger killing. Following the creation of such a mechanism, it would become fixed in the given species and would simultaneously cease to be manifested externally in the phenotype. If such a mechanism were not created, the action of sister-killers could even lead to the extinction of the particular species. The third possibility is apparently most probable – through the drastic selection pressure of sister-killer alleles, alleles would become fixed at some locus that would provide their carriers with resistance to sister-killer alleles. Species exposed to constant waves of fixation of sister-killer alleles would, of course, be at a disadvantage compared to species in which a mechanism would exist to prevent the formation of these alleles in advance, so that this mechanism could be fixed in the biosphere by species selection (IV.8.4). Meiosis and other currently known means of creation of haploid sex cells could be the mechanism for preventing the spreading of sister-killer alleles.

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The classical Darwinian theory of evolution can explain the evolution of adaptive traits only in asexual organisms. The frozen plasticity theory is much more general: It can also explain the origin and evolution of adaptive traits in both asexual and sexual organisms Read more