Dental development among primates, including humans, correlates tightly with other important traits including life span, age at reproduction, and brain growth.
Given the changing metabolism of bone across the life span, age must ultimately be factored in as well.
As proposed by Martin and Palumbi [ 9], high rates of nucleotide substitutions observed in mitochondrial genes could be related to some physiological variables such as generation time, life span, age at first reproduction, rate of population increase, and metabolic rate.
The great interest in the ageing research which is observed lately has been inspired by lengthening of the average human life span (age at which 50% of a given population survives), lengthening of the maximum human life span (longest-lived member of the population), and elevated percentage of the elderly and very elderly in the populations [ 1].
Under these conditions, enhanced antioxidant defenses exert an "antiaging" action, leading to changes in life span, age-related pathology, and physiological function as predicted by the oxidative stress theory of aging.
In addition to the accumulation of oxidative damage during a life span, aging is directly associated with an impaired antioxidant defense mechanism.
The finding also gave a chance to search for genes affecting fitness-related traits linked with diapause, e.g. life span, age-specific mortality, fecundity, resistance to cold and starvation stress, lipid content, development time, egg-to adult viability, accessory gland synthesis and mating behaviour [ 8- 10].
These effects of Sir2 suggest paradigms in which genes that promote genome stabilization through chromatin modulation may be important contributors to regulation of organismal life span, aging, and age-related pathology.
The recent World Report on Cancer indicates that by 2030 the majority of the population affected by cancer will be in low- and middle-income countries (LMIC), as they transition towards higher levels of the Human Development Index, with concomitant increasing life span, aging populations, and rapid changes of socio-economic and lifestyle factors [ 34].
Metabolic rate, for example, varies in proportion to the 3/4 power of an organism's mass--the bigger the creature, the slower its metabolism--and similar relationships have been found for variables such as life-span, age at sexual maturation, and length of pregnancy (1/4, 3/4, and -1/4 powers of mass).
We examined the associations of menopausal age and reproductive life span (menopausal age minus menarcheal age) with diabetes risk.
