Aging of biological systems is a complex process that is controlled by genetic, environmental, and stochastic traits. It is characterized by the irreversible decline of physiological functions and finally the death of the system. The understanding of the underlying molecular mechanisms is of paramount importance with a wide relevance to general biology, ecology, biotechnology, and medicine. Research on various systems unraveled many aspects and mechanistic pathways which impact on biological agingagingbiological and lifespan. Among these systems, fungi were the first which provided substantial evidence for a role of mitochondriamitochondria, the cellular “power plants,” in triggering aging. Today, the decline and dysfunction of mitochondria is accepted as a basic hallmark of agingaginghallmark of that is conserved from simple organisms like fungi to the human species.