Maternal effects and additive genetic inheritance in the collared lemming Dicrostonyx groenlandicus

We examined patterns of inheritance of size, growth and behavioural traits of collared lemmings (Dicrostonyx groenlandicus). Work was conducted on field-caught parents from the Canadian Arctic and their lab-born progeny. We partitioned inherited variance in traits into additive genetic and maternal effects components by using a half-sib breeding experiment in which each sire was mated to two dams. We found no evidence of statistically significant amounts of additive genetic variance in any of the traits measured. However, significant maternal effects were detected for several size- and growth-related traits. Three behavioural traits involving aggression, dispersal and activity showed no statistically significant inheritance of any kind. The presence of maternal effects may have consequences for population dynamics by causing 'lags' resulting in inappropriate phenotypes being produced under regimes of fluctuating selection pressure. We recommend that maternal effects should be investigated as a potential general cause of population cycles in small mammals.