We model and discuss advantages of pan-editing, the complex way of expressing
mitochondrial genes in kinetoplastids. The rapid spread and preservation of pan-editing
seems to be due to its concomitant fragment dispersal. Such dispersal prevents losing
temporarily non expressed mitochondrial genes upon intense intraspecific competition,
by linking non expressed fragments to parts which are still needed. We mathematically
modelled protection against gene loss, due to the absence of selection, by this kind of
fragment association. This gives ranges of values for parameters like scrambling extent,
population size, and number of generations still retaining full genomes despite limited
selection. Values obtained seem consistent with those observed. We find a quasi-linear
correlation between dispersal and number of generations after which populations lose
genes, showing that pan-editing can be selected to effectively limit gene loss under
relaxed selective pressure