The results of recent molecular biological studies of aging and longevity confirmed substantial genetic contribution to the life span. The analysis of these findings showed substantial role of specific mutations in genes involved in regulatory processes on both the extra- and intracellular levels. We suggest that difference in responses of intact and mutant animals to the same set of environmental signals may be useful to clarify contribution of organism-environment interactions into the rate of aging, mortality and longevity of respective organisms. In our opinion such clarification is important for better understanding the origin of natural senescence and its dependence on external conditions.