An Evolutionary Model in Which Aging is Selected

The present consensus on the evolution of aging is that it is an inevitable side effect of natural selection - aging isn't selected for per se, it is a byproduct. Evolution favors reproduction earlier in life rather than later in life, particularly in environments with high mortality due to disease or predation, and thus there is little pressure to select for mutations that enhance long-term maintenance of the body and brain. Looking at the examples of biology around us, the outcome of this process is near always biological systems that fail over time, in which their structure is optimized for early life success at the cost of late life health. This state of affairs is called antagonistic pleiotropy, that many (even most) biological features are great for health when young, terrible for health when old. This consensus is not without its heretics, those who argue that aging is under selection, that degeneration of the individual is in some way advantageous to fitness of the species. This is often called "programmed aging". It is argued to occur, for example, because aging species might better adapt to periodic sizable environment changes, or as a result of group selection effects such a continual reduction of the breeding population via aging minimizing the odds of a population explosion. Many of these arguments are presented in the form of a model, and that is the case in today's open access paper. Whether the argument is interesting or not tends to depend on the fine ...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs