Adapt or die
Die earlier to adapt faster
Adapt or Die => Die Sooner to Adapt FasterJosh Mitteldorf, translated by Evgenia Ryabtseva
In the long run, the ability of a species to evolve is the most important factor determining its success in competition. In other words, given enough time, the ability to adapt and improve overcomes any initial shortcomings.
Over the past 50 years, evolutionary theory has been rather skeptical about the concept of a "long-term plan". If, in the short term, uncompetitiveness leads to the extinction of a species, what significance can its ability to improve have?
This pattern fully extends to aging. A population whose individuals are aging is characterized by greater diversity and a shorter renewal cycle compared to a population whose mortality is due only to hunger, predators, diseases, etc. Thus, theoretically, the population of aging individuals evolves faster than the population of individuals who are not capable of aging. However, a "long-term period" can mean thousands of generations, and during this time, individuals who die early (from old age) are at a competitive disadvantage compared to individuals who continue to live and have more opportunities to leave offspring.
Can an aging population withstand the invasion of long-lived competitors and maintain its existence for so long that its higher rate of adaptation will turn into a decisive advantage? The author has been studying this issue for the last ten years. On the one hand, there is a large amount of evidence in favor of the fact that aging is not an accident, but the result of evolution, which appeared under the pressure of natural selection, which undoubtedly contributed to its appearance. On the other hand, there is a theoretical argument that raises doubts about the reality of this scenario.
According to the most plausible explanation of this paradox, aging may be an evolutionary result of the described scenario, because the short-term benefits of unlimited reproduction were restrained by other fast-acting evolutionary principles other than the ability to evolve. Unlimited reproduction leads to excessive growth, crisis and disappearance of the population. This mechanism is a powerful, fast-acting evolutionary force, and populations have had to adapt by mitigating competition between individuals. This has created an environment in which the long-term benefits of aging have weight, and aging is fully manifested as adaptation at the population level.
Among the representatives of the educated public, two views on aging prevail. According to one of them, aging organisms wear out as mechanisms in which various kinds of damage accumulate over time. According to the second, aging and death are programmed in the genes to free up living space for the next generation.
However, both theories were discredited more than 100 years ago. Regarding the first, doctors say that "this does not correspond to the principle of entropy." Regarding the second, evolutionary biologists claim that "natural selection acts differently."
There is a third theory among experts in evolutionary biology, according to which aging is not a direct product of evolution, but the result of the selection of genes that promote reproduction at an early age.
In the article "Programmed life span in the context of evolvability" published in the September issue of the journal American Naturalist, two physicists – Joshua Mittendorf and Andre C. R. Martins – challenge evolutionists by describing a model demonstrating how "the liberation of living space for the next generation" can be a viable selection mechanism.
Of course, the plausibility of this model does not mean that in nature everything happens in this way. However, the authors claim that their model provides a much better explanation of the latest genetic data than the generally accepted theory formulated before the advent of modern science of genetics.
According to Mitteldorff, genes promoting aging have been identified in a number of animals used as model organisms. Most of these genes are absolutely unrelated to fertility, which contradicts the classical evolutionary theory. Some of these genes have ancient roots, right down to primitive organisms that lived a billion years ago. Any trait that has been preserved for such a long period should have an adaptive function.
Martins, in turn, explains that aging is a classic case of conflict between an individual and a community. In the 1960s, evolutionists were of the opinion that in such conflicts the individual always prevails. The model created by the authors demonstrates the opposite. In recent years, computer modeling has played a major role in the rehabilitation of "group selection", and both authors have previously published computer models in which aging was able to evolve due to the fact that the benefits for the group outweighed the losses of individuals. As a result, this provided an opportunity for more effective development at the population level.
More detailed mathematical models describing these processes can be found in the article mentioned above.
11.09.2014