Information and knowledge in biology: time for reappraisal.

The second law of thermodynamics accounts for irreversibility of processes in the universe. As a statement about increasing disorder, it also plays a central role in creating order. Structuring is a way of how to increase the rate of dissipation of matter and energy. This is the reason why chemical reactions on Earth have produced a profusion of structures. Chemical structures with particularly high stability, maintained by continual dissipation, are designated, somewhat arbitrarily, as living systems. To preserve stability, organisms are unceasingly performing ontic work, assisted by epistemic work. Biological evolution is a progressing process of knowledge acquisition (cognition) and, correspondingly, of growth of complexity. The acquired knowledge represents epistemic complexity. Biological species are the main "bookkeepers" of acquired knowledge, with individual members of the species functioning as "explorers" of novelty. Science, a human species-specific mode of acquiring knowledge, abounds in metaphors no less than art. In the postgenomic era, the metaphor of information, along with the related metaphor of selfish genes, may need reconsideration and/or complementation. The world of great complexity, which is becoming the focus of studies of contemporary biology, may require-similarly as is the case of quantum physics-descriptions based on the principle of complementarity. Embodied knowledge, molecular engine, ontic and epistemic work, and triggering may become parts of a new conceptual armory.