deleterious mutation
Keightley PD, Caballero A & García-Dorado A 1998 Population genetics: surviving under mutation pressure. Curr Biol 8:R235-R237.
- it is extremely difficult to obtain information on the impact of mildly deleterious mutations
- currently, much of what we know comes from experiments done in the 1960s and 1970s by Mukai and coworkers
- they maintained specially constructed lines for many generations in benign conditions to allow mutation accumulation
- in competitive test conditions, viability was found to decline by as much as 2% per generation
- this was mostly attributable to mutations with detrimental effects of the order of a few percent
- with a much smaller contribution from lethal and severely detrimental mutations
- these results are widely used in evolutionary models, and permeate the population genetics literature
- recently, Mukai's results have been questioned
- on the grounds that part of the apparent decline in viability could have been non-mutational
- the rates of accumulation of lethal or severely detrimental mutations are not in question
- it is the overall fitness-reducing effect of mildly deleterious mutations
- which could be much lower than Mukai's results suggest
