Thesis #39 – Patterns of adaptation are jointly determined by long-antecedent evolutionary patterns of natural selection, mutation, and inbreeding, as well as the immediate impact of environmental manipulation.
In studying the aging phase and other patterns of adaptation in an experimental organism, or in considering our own patterns of adaptation, we are confronted with a host of impinging factors. From the start of the 55, we have paid attention to the key role of natural selection. This then led us to emphasize the key constraints shaping what natural selection can accomplish, including mutation and inbreeding, but also the declining forces of natural selection during the adult years.
But the additional considerations that have just been outlined also reveal that overlaid on top of whatever evolutionary adaptations a population possesses will be the environment in which that population lives. This can be put in a relatively simple way. There is no such thing as “AGING,” considered as some kind of absolute process of deterioration, independent of environment.
Instead, there are different patterns of deteriorating early-adult adaptation which individuals from a population with evolutionary age-structure will show at particular points in its evolutionary history, and in particular environments. Adaptation is fundamentally a transitory thing, dependent on prior evolutionary history, and dependent on the environments in which organisms now live. As aging is merely this age-specific deterioration of adaptation during the first part of adulthood, it is just as affected by prior evolutionary history and present environmental conditions as adaptation in general.
Such effects are very dramatic in the commonly studied experimental organisms, like fruit flies and nematodes. Giving them novel foods or changing the ambient temperatures of the laboratory vessels in which they are maintained can produce radically different results with respect to rates of aging and the timing of its cessation, where “rates of aging” means the rate at which adaptation deteriorates, NOT the rate at which at a hypothetical physiological process of aging unfolds.
But as we too are products of evolution, these strictures apply to us just as much as they do to our experimental organisms. This is what is particularly promising. Those who study aging are slowly becoming convinced of its tremendous plasticity. If I may be a bit self-referential here, throughout my 35 years of experimental research on aging, I have been surprised again and again by how readily aging changes, both in response to experimental evolution and in physiological response to environmental change. Properly exploited, such plasticity offers the possibility of greatly ameliorating human aging, if only we could figure out how best to take advantage what our evolutionary history has made us. It is on this front that the 55 theses offer the most immediate promise for human welfare. But in order to get to that promise, you first have to realize how little value there is to be extracted from non-evolutionary strategies and findings in aging research. You have to be particularly clear about this because non-evolutionary researchers are likely to reject the promising news on offer here, and they will further attempt to distract with a barrage of spurious arguments. Such intellectual gesticulation and obfuscation is common enough in science; it is just regrettable when it leads to shortened or straitened lives. Do you really want to suffer or die for sake of the intellectual limitations of defensive scientists?