ABSTRACT
This chapter aims to curate many quantitative patterns of aging. Risk of death is age dependent. Risk of death is high in the first year: the human life cycle begins with rapid growth of the embryo with accompanying diseases and delivery risks. Genetically identical organisms grown in the same conditions, such as identical twin lab mice, die at different times despite having the same genes and environment. Research on model organisms shows that lifespan can be extended. Certain mutations and interventions extend lifespan in roundworms up to three-fold, and in mice by up to 50%. There are several molecular theories of aging, each focusing on a particular kind of damage to the cell and its components. The main types of cellular damage include DNA damage, protein damage, and damage to the cells’ membranes or their energy factories called mitochondria. Stem cells are found for example in the epithelial lining of the intestine, lungs and skin.
