Sex, ageing and mitochondria Summary An hypothesis is presented by which gamete specialisation resolves a conflict between the function and replication of mitochondria. Mitochondrial function is synthesis of ATP by oxidative phosphorylation, coupled to respiratory electron transport. This requires a mitochondrial genetic system.
Mitochondrial function is therefore detrimental to the fidelity of mitochondrial replication.
Damage to somatic mitochondrial DNA may accumulate within, and indeed determine, the life span of individual organisms. This testable hypothesis may help to explain the evolution of separate sexes and a number of their characteristics. Maternal inheritance of chloroplasts may be explained in a similar way, and contribute to the maintenance of separate sexes in plants.