In most biological models, to reproduce as identical or similar organisms, mitosis is based on the extreme accuracy of the mechanisms involved in the even transmission of the genetic material in the two daughter cells. Character recombination and genotype diversification are insured by the alternation between haploidy and diploidy, which corresponds to the most predominant model in sexually reproducing organisms. In Leishmania, the unique association of high levels of automixis and of a constitutive 'mosaic aneuploidy', unexpectedly does not lead to loss of heterozygosity but constitutes an alternative for genotype recombination, hence a source of adaptability.