The review discusses the role of gene duplications in evolution. Duplications enable block-modular gene reorganizations that combine fragments from different genes and give rise to proteins with differing functions. Such genetic events are exemplified, for instance, by consecutive duplications and subsequent divergence of the genes encoding color-sensitive pigment proteins, which made possible trichromatic vision in humans and Old World monkeys. On the other hand, many proteins involved in the regulation of protein synthesis have appeared as a result of a series of gene duplications that gave rise to modern translation elongation and termination factors. Supposedly, the proteins controlling the quality of newly synthesized mRNA also originated by duplication of the genes encoding ancient translation elongation factors. Their subsequent divergence gave rise to proteins with new properties, which were, however, no longer able to participate in the control of translation.