On some reliability approaches to human aging

Deceleration in mortality rates for old ages is explained via the concept of population heterogeneity. Two simple probabilistic models of biological aging are considered. The first one assumes that some random resource is acquired by an organism at birth. Death occurs when the accumulated wear exceeds the initial random resource. In the second model death occurs as the consequence of a harmful event. A non-homogeneous Poisson and doubly stochastic Poisson processes of harmful events are considered. These models describe possible causes of population heterogeneity