Larger fetuses of monotocous species are more prone to maldisposition than relatively small ovoid fetuses of polytocous
species (Jackson, 1995).
Many researchers have studied either genes or factors affecting litter size in single species instead of directly focusing on the differences between monotocous and polytocous species.
In order to identify important genes that underlie the differences between monotocous and polytocous species, a novel approach focusing on the evolutionary genetic differences between the two groups of species was applied.
Human, chimpanzee, orangutan, macaque, panda, horse, cow and dolphin were selected as monotocous species, and mouse, rat, dog, cat, pig and Tasmanian devil were selected as polytocous species with the platypus as an outgroup.
Ontogeny of sexual dimorphism in size among polytocous
mammals: tests of two carnivo- rous marsupials.
College Dublin, Ireland) have collected these papers for policymakers and researchers in agricultural sciences, covering such topics as the behavioral indicators of animal health and welfare, poultry housing and environment, resting behaviors as an assessment tool, the influence of genetics and breeding on animal welfare and mother-offspring behavior in polytocous
Indeed, individual offspring of polytocous ungulates that produce 2 offspring per breeding attempt might be lighter at birth than single offspring of monotocous ungulates (Roff 1992).
I can thus also conclude that moose allocate energy to maternal care as a monotocous species during the gestation period but as a polytocous species during the lactation period.
To earn the inheritance, Tse will have to keep discovering new substances and processes from which to bring forth her polytocous
Litter size declines with age and parity in females of many, but not all, species of polytocous
domestic and wild mammals (Sadleir, 1969; Nalbandov, 1976).
In this work, we report a quantitative analysis of family effects on life-history traits in a polytocous ungulate, the roe deer (Capreolus capreolus).
The pervasiveness of family effects in our study of roe deer suggests that family effects should occur in other polytocous species, at least in ungulates.