A population experiencing mutational meltdown is trapped in a downward spiral and will go extinct if the phenomenon lasts for some time.
The smaller population size allows for more rapid fixation of deleterious mutations, and a more rapid decline of population size, which becomes irreversible after a certain number of generations[3] In asexual species, the effects of mutation accumulation are more significant compared to sexual species.
In an asexual population, all the individual species are equally affected by the selective pressures from the environment, which includes, deleterious and/or beneficial mutations.
This is due to the lack of recombination of alleles and diversity in the genome that allows the accumulation of mutations to effectively take over the asexual population.
In simulated models of sexually reproductive species being introduced to an accumulation of deleterious alleles, it was shown that the population will not go extinct, or it takes an exponential amount of time to do so.
Factors that include low birth and recombination rate, as well as having a strong mutation-selection, can cause a large sexually reproducing population to go extinct.
In a tested environment, where variables can be theoretically manipulated, the strong mutation-selection in a large sexually reproducing population can be prevented from mutational meltdown if the birth rate were to increase.
The filamentous multicellular bacterium Streptomyces coelicolor forms colonies in which a subpopulation of cells arise that hyperproduce beneficial, but metabolically costly antibiotics.