Natural Selection or the Non-survival of the Non-fit

The effects of natural selection as a process in natural populations differs from 'survival of the fittest' as it was formulated by Darwin in his 'Origin of Species'. The environment of a population exists of continuous changing conditions, which are heterogeneous in space. During its life each individual successively meets with differing conditions. During these confrontations the individual may appear to be 'unfit' or 'unlucky' and may die. If it survives it will meet the following conditions to which it is 'tested' anew, a.s.o. Hence, many individuals being less fit under certain conditions will survive and reproduce, because they did not meet a deadly moment. Therefore, being 'fit' only refers to special prevalent conditions. In each generation the individuals thus being 'unfit' will be eliminated together with the 'unlucky' ones. All other individuals will survive and reproduce, notwithstanding their properties.Hence, natural selection results in the 'non-survival of the non-fit' rather than in 'survival of the fittest', because being 'fit' simply means 'having survived and reproduced', whereas being 'unfit' can be connected with many kinds of properties and environmental conditions, e.g. being killed by a predator. Only after many generations (hundreds or even thousands) the effect of eventually dominating properties of the survivors may result in a set of properties suggesting an overall 'survival of the fittest'. This was what Darwin wanted to explain as he was mainly interested in evolutionary processes.As natural selection, as an ecological process, cannot be considered in each generation to be 'survival of the fittest', many ecological concepts supposed to be connected with selection resulting in 'survival of the fittest' within a few generations, such as the dominant role of competition, the critical level of the costs of reproduction, the need of optimization and of optimal life-history traits have to be reconsidered more critically in a less deterministic context. Moreover, these aspects of natural selection, which usually lead to impoverishment of the genepool, contradict the need of a high level of genetic heterogeneity as a base for an effective natural selection.The author gives examples of cases to which these concepts do not apply. On the other hand, natural selection resulting in 'non-survival of the non-fit' allows a continuous reshuffling of all kinds of genes and gene combinations over all kinds of genomes, also many genes with temporarily or even permanently unfavourable effects can be kept in the genepool of the population during a long series of generations. Therefore, natural selection resulting in 'non-survival of the non-fit' leads to spreading of the risk of extinction of the population over genotypes and to the gradual development and accumulation of highly sophisticated adaptations. Only in an environment that has been stationary or even almost constant and homogeneous for a long time may natural selection ultimately lead to 'survival of the fittest'.