Two major sources of mutation are radiation and reactive oxygen species (ROS).The reactive oxygen species hypothesis for aging postulates that 1) Senescence results from the accumulation of DNA, lipid, and protein damage inflicted by ROS of mitochondrial origin; and2) Mitochondria of long-lived species should produce high ROS than do mitochondria of short-lived species.3) the capacity of mitochondria to consume ROS might distinguish long-lived species from short-lived species, rather than differences in ROS generation. -triyambak.org