MATERNAL EFFECTS AND ADDITIVE GENETIC INHERITANCE IN THE COLLARED LEMMING DICROSTONYX GROENLANDICUS

We examined patterns of inheritance of size, growth and behavioural tr aits of collared lemmings (Dicrostonyx groenlandicus). Work was conduc ted on field-caught parents from the Canadian Arctic and their lab-bor n progeny. We partitioned inherited variance in traits into additive g enetic and maternal effects components by using a half-sib breeding ex periment in which each sire was mated to two dams. We found no evidenc e of statistically significant amounts of additive genetic variance in any of the traits measured. However, significant maternal effects wer e detected for several size- and growth-related traits. Three behaviou ral traits involving aggression, dispersal and activity showed no stat istically significant inheritance of any kind. The presence of materna l effects may have consequences for population dynamics by causing 'la gs' 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 cyc les in small mammals.