A gigantic amounts of data and information on molecules that constitute the very complex cell machinery have been collected, classified and stored in data banks. Although we posses enormous amount of knowledge about the properties and functions of thousands of molecular entities, we are still far from understanding how they do work in a living cell. It is clear now that these molecules (genes, proteins) are not autonomous, that there is no direct linear relation between genotype and phenotype, and that the majority of functions are carried and executed by concerted molecular activity, and that the majority of diseases are multifactorial. A basic property of the matter in a living cell (both normal and pathologic) is an interaction between variety of macromolecules, mainly proteins, genes (DNA) etc. In a process of self-organization they are able to form an active molecular biologic system – a complex, labile and dynamic network which integrity is secured by non-covalent bounds. In this essay some basic properties of network structure and the universal rules that govern them are described. Network or system biology is promising new research approach in biology and medicine.
Animal behaviour and its underlying causal factors are investigated by numerous behavioural sciences. Ethology, one of the most important classical behavioural sciences, is concerned with the description and quantification of behaviour and the analysis of a wide spectre of its causal factors. Ethology also lays stress on the importance of comparative behavioural research and field research. Specific behaviour paterns were considered by classical ethology as elements of hierarchically organised behavioural systems focused on specific functions. The notion of instinct was, however, far from unequivocal and is no more frequently used in behavioural sciences. We also know that information flow between the levels of organization existing in the nervous system and in living systems in general is multidirectional. The assumption that processes running on higher levels of organization can and should be explained solely in terms of processes running on lower levels becomes thus largely groundless. In behavioural sciences reductionism can manifest itself also as the so called law of parsimony adopted during explanations of observed phenomena (Occam’s razor, Lloyd Morgan’s canon). Since the introduction of Karl Popper’s falisifiability criterion to the methodology of scientific research, reductionistic explanations of observed phenomena are, however, less frequently proposed in behavioural sciences. Instead, an approach currently used involves experimental testing of sets of hypotheses proposing alternative explanations of the observed phenomena, not necessarily the simplest ones. Classical ethology was the so called objectivist science of behaviour: its adherents did not deny the existence of subjective phenomena in animals, however, explanations of mechanisms of investigated phenomena in terms of underlying subjective processes were not considered to be sufficient. Presently we may put forward increasingly daring hypotheses concerning subjective experiences of animals thanks to the development of advanced techniques of neuroimaging such as the functional magnetic resonance imaging (fMRI). Behavioural sciences are constantly progressing and their methods become increasingly sophisticated. We can thus hope that philosophy and behavioural sciences will continue during a long time yet to contribute jointly to achieve new insights enriching our knowledge on factors influencing animal and human behaviour.