While this expectation has been confirmed by a number of observations [ 2], it does not explain the advantages of a mixed reproductive strategy involving clonal reproduction in particular.
Thus, clonal reproduction serves as a means of reproductive assurance.
This unusual reproductive mode, called apomixis, leads to clonal reproduction in that all offspring are by and large genetically identical to the parent.
Even with strictly clonal reproduction, for which traditional ideas of speciation based on reproductive isolation do not apply, specialization to distinct niches can cause the emergence of independently evolving genetic clusters (Barraclough et al. 2012).
Thirty-four of the 38 nests that lacked reproductives at the time of collection provided indirect proof of clonal reproduction by both queens and males (i.e. inferred queen genotypes identical to known clonal queen genotypes and inferred male genotypes identical to known clonal male genotypes).
One feature of this reproductive adaptation is the emergence of males, which impose costs on sex that are not borne by clonal reproduction [ 1- 4]. Cloning should be widely prevalent as a consequence and sex under constant threat of extinction.
Competition for reproductive resources in perennial plants can give rise to significant variation in the balance between sexual and asexual (clonal) reproduction.
The extent of clonality together with the clonal and sexual reproductive strategies varied greatly among the nine populations and correlated with the habitats where they occur.
Though clonal, asexual reproduction is the main reproductive mode in the Cryptococcus species complex, the existence of recombination and putative sexual reproduction has been demonstrated in several natural populations [31], [35], [41], [42].
Self-fertilization and clonal propagation are both reproductive systems that have been characterized as evolutionary dead ends because of the potential for genetic degradation through accumulation of deleterious mutations and the loss of adaptive potential through reduced genetic variation (Klekowski 2003; Takebayashi and Morrell 2003).
