The prediction that large increases in mutation rate cause major reductions in fitness is based on the supposition that most mutations with fitness effects are deleterious and that the effects of these deleterious mutations are either additive or negatively synergistic.
Lowering the mutation rate caused the evolution of parasites, which, however, enabled the evolution of even greater diversity.
However, uniform deviation of the rate of synonymous evolution from the mutation rate, caused by selection, cannot be taken into account in this way.
Previous analyses of some intronic fragments show chicken and other birds have a significantly higher level of neutral sequence divergence on Z chromosome than autosomes, indicating a higher Z-linked mutation rate caused by the male-driven evolution effect.
Because the LINE-1 methylation levels of each locus are distinct, the mutation rate caused by RIND-EDSB repair errors is dependent on the methylation status of the genome near the EDSBs.
However, the major challenge limiting current therapy is the rapid evolution of drug resistance resulting from the high mutation rate caused by the absence of a proofreading function in HIV reverse transcriptase.
In addition, given our estimate of the small effective population size within MA lines (10.26 cells), and the location of mutations in the MA lines indicating ineffectual selection, we favor increased mutation rate, caused by a high propensity for double-stranded breaks, as the explanation for more mutations occurring in these genes.
I suggest that the combination of a high mutation rate (caused by intron attack) with the elimination of genome size constraints and the loss of the cell wall, enabled cell fusions and genome duplications--the origin of a sexual cell cycle--placing many theoretical ideas on the origin of sex in a specific setting.
This mutational event was presumably selected for during early tumorigenesis in cells with a high mutation rate caused by a constitutive MMR defect, but, since TDG was not inactivated in tumors of three other CMMR-D patients, the loss of this enzyme is likely not an obligate step in the malignant transformation of the colonic epithelium of such patients.
We show that this effect is largely due to sites with elevated mutation rates causing significant departures from the widely-used infinite sites mutation model.
