What determines the life span of a species

Diverging in the initial assumptions, both mechanistic and evolutionary theories of aging suggest a positive correlation of specific indicators of life expectancy with body size and a negative correlation with fertility and metabolic rate. Such dependence is obviously traced within large taxes, however, when analyzing on a smaller scale (at the level of orders and families), ecological specialization of species can make a significant contribution to the variability of the corresponding indicators. In the suggested work, correlative relationships between median and maximum life expectancy, on the one hand, and the average values of body weight, fertility, muscle strength, values of standard and maximum metabolic rates, locomotor activity and emotionality in the open field test, on the other hand, are analyzed in 8 species of Cricetidae family. The correlations with life expectancy were significant for all indicators except body weight. For motor activity, the correlation with life expectancy was positive, for other indicators - negative. The paper discusses possible reasons for differences in the strength of correlative relationships of the analyzed indicators with the maximum and median life expectancy from the point of view of mechanistic and evolutionary approaches to the analysis of the causes and mechanisms of aging.