mutation accumulation
Gilligan DM, Woodworth LM, Montgomery ME, Briscoe DA & Frankham R 1997 Is mutation accumulation a threat to the survival of endangered populations? Conserv Biol 11:1235-1241.
- no trend of smaller populations exhibiting greater genetic loads than larger ones was observed under either benign or competitive conditions
- genetic loads were similar in captive and wild populations
- neither deleterious nor lethal allele frequencies exhibited a relationship with population size
- the accumulation of detrimental mutations does not appear to pose a significant threat to finite sexual populations with effective sizes of 25 or more over the 100-200 year time frames considered in most wildlife conservation programs
- why didn't we detect an increased mutation load of the type predicted by the Lande (1994) and Lynch et al. (1995a, 1995b) models?
- data on the actual distribution of mutational effects for fitness characters is limited, especially for mutations of small effect
- the actual distribution of mutation effects does not exhibit a large enough tail of weakly selected mutations for their fixation to substantially increase the genetic load in sexual populations
- the Lande (1994) and Lynch et al. (1995a, 1995b) models do not include the effects of beneficial mutations, and so overestimate extinction risk
- mutation accumulation does not appear to represent a major threat in wildlife conservation programs
