Effects of disturbances vary in space and time and depend, among other things, on the type and age of organisms, the habitat being studied and the complex interactions occurring in the systems.
Moreover, these genes have been used as age biomarkers to establish the physiological age of organisms [26], [27], detect tissue-specific aging differences [24], [28], [29], [30] and study the biology of aging-related diseases [31], [32].
In spite of these variously good and bad effects of cellular senescence, recent studies support the idea that accumulation of senescent cells with the aging of organisms accelerates age-associated diseases and loss of tissue function (Baker et al., 2011).
Since differences in the circulating miRNAs have been found in a variety of age-associated diseases, and accumulation of senescent cells in the elderly emerges as a possible detrimental factor in aging, it is well conceivable that these miRNAs might contribute to the functional decline observed during aging of organisms.
Successful attainment of the goals depends primarily on the maintenance of species diversity and the age composition of organisms, as well as on the structural complexity of riparian soils, plant cover, and associated communities.
Aging of organism, tissues, or cells is a complicated and irreversible process, but the time when it occurs and the pace of the process may be regulated.
The higher the age of an organism, the greater the organism's contribution to fitness that cannot be affected by any event happening at that age, because that contribution lies in the past.
It tells us that the age of an organism, or an organ like the brain, is not written in stone.
If aging is due to or contributed by free radical reactions, as postulated by the free radical theory of aging, lifespan of organisms should be extended by administration of exogenous antioxidants.
Although the expression level of a gene is affected by a large number of variables (age of the organism, the position within the organism, phase of the cell cycle, environmental stress, etc).
Therefore, our findings also suggest the presence of a common mechanism that regulates longevity and aging in a range of organisms.
