Molecular basis of the biological evolution

According to the Neo-Darwinian theory Of evolution spontaneous mutagenesis is the driving force of biological evolution. while the direction of evolution depends on natural selection together with the available genetic variants. The methods of molecular genetics enable us to investigate the molecular mechanisms of genetic variation. Such studies can best be done with bacteria. Their haploid genome manifests rapidly the phenotypes of new mutations. Altered nucleotide sequences are rather rarely of advantage, more often they are of disadvantage or neutral. Several specific mechanisms contribute to the overall mutagenesis. These mechanisms can be classified into three natural strategies of genetic variation: (i) a local change of the nucleotide sequence, (ii) the rearrangement of DNA segments within the genome, and (iii) the acquisition of a DNA segment from another kind of organism by horizontal gene transfer. Selected examples for the three natural strategies of genetic variation can also illustrate the qualitative differences of the contribution,,, made by the strategies to the evolutionary process. On the basis of knowledge on the molecular mechanisms of genetic variation the theory of molecular evolution postulates that products of so-called evolution genes are involved in mutagenesis together with diverse non-genetic factors. The evolution genes provide to the organisms their evolutionary fitness. The knowledge on molecular evolution extends our knowledge on nature. With regard to its philosophical value we can search for ways to reach a general agreement between scientific knowledge, on the one hand, and traditional wisdom and religious beliefs on the other hand.