Enormous advances in our knowledge of genetic contributions to ageing and disease, and in our understanding of the potential for manipulation of the ageing process, have taken place during the past twenty years. This is the first volume in decades to consolidate this research in one place. It provides a broad and current overview of the most promising advances in genetic research on ageing, current understanding of genetic contributions to the basic processes of ageing, and age-related disease. The Review focuses on the ageing process from lower organisms to man, and is organised in ascending order of biological complexity starting with stem cells and progressing through worms, flies, mice and humans. Where relevant, the Review also includes information about yeasts and non-human primates. The research presented in the Review uses a species comparative approach that makes finding cross species similarities (gene conservation) and differences (gene differentiation) apparent. This approach reflects the way in which the field is organised, making it highly useful for investigators who want quick access and a concise summary of a particular topic.