Frozen Evolution. Or, that’s not the way it is, Mr. Darwin. A Farewell to Selfish Gene.

Other categories of mutations, genome mutations, affect entire chromosomes or entire chromosome sets.In contrast to the previous types of mutations, these mutations are not formed as a consequence of irregularity in DNA replication or repairing, but as a consequence of irregularities and errors  in the progress of cellular division.As a consequence of these disorders, organisms can be formed in which a certain chromosome is multiplied or, on the other hand, is lacking (aneuploidy); in other cases, the entire chromosome series is multiplied (polyploidy).Depending on the number of specimens of a given chromosome occurring in the cell, this can correspond to nulisomics, disomics, trisomics, etc.On the basis of the number of chromosome sets, these are then haploid, triploid, tetraploid, etc. organisms.It was found in a study of human sperm that the frequency of diploid sperm varies around 0.2% and the frequency of haploid sperm with multiplication of one of the four monitored chromosomes varied from 0.1 to 0.17% (Miharu, Best, & Young 1994).

            In most animals, the sex of the organism is determined by the gene dose and individuals with aberrant autosome ratios and sex chromosomes have transitory traits between males and females, i.e. are intersexes, and are mostly not capable of reproduction.Analogous disorders can occur for uneven gene doses at various chromosomes (cf. the Down syndrome in human beings, caused by trisomy of chromosome 21).Thus, these mutations are of only limited evolutionary importance for animals.However, the situation is very different, for example, for plants, in which the gene dose does not play a role in determining the sex and in which polyploidy thus generally does not have a detrimental effect on the viability or fertility of the mutant (Muller 1925).