Peter Csermely (Budapest)
Successful crisis survival strategies: What can we learn from biological networks surviving a few billion years?
Networks not only give us a visual image of complex systems providing an instant recognition of groups and important elements, but also have a number of structural features, which are general properties of biological, social and engineered networks. The small-world character, the existence of hubs, modules, hierarchy and many others are amongst these features. Our highly multidisciplinary group (www.linkgroup.hu) uses networks as ‘highways’ making the transfer of concepts between various disciplines rather easy. This concept-transfer embeds the original idea to the entirely different context of another scientific field, and helps to solve creativity deadlocks. As an example the common early warning signals of critical transitions in ecosystems, economy and climate are hallmarks of the behavior of aging organisms posing aging as an early warning signal of a critical phase transition: death.
These generalizations allow the utilization of the ‘wisdom’ of biological systems surviving crisis events for many billions of years. As an example of network dynamics in biological systems the lecture will show the systems level crisis responses of a yeast cell. When the community structure of the protein-protein interaction network of yeast cells were studied, the overlap of protein communities decreased, and their modules became partially disintegrated as an initial response to stress. The stress-induced decrease of inter-modular connections was beneficial, since it A.) allowed a better focusing on vital functions, and thus spared resources; B.) localized damage (e.g. of free radicals) to the affected modules; C.) reduced the propagation of noise; D.) allowed a larger ‘degree of freedom’ of the individual modules to explore different adaptation strategies; and E.) helped the ‘mediation of inter-modular conflicts’ during a period of violent intra-modular changes. Modular reorganization emerged as general and novel systems level way of cost-efficient adaptation. Inter-modular nodes, such as the highly dynamic ‘creative elements’ play a particularly important role in this adaptive process. Their presence not only determines the systems potential for fast adaptation, but also gives a life insurance in crisis. These elements bridge Ronald S. Burt’s ‘structural holes’, and provide a key subset of Mark Granovetter’s ‘weak links’. Active centers and binding sites of proteins often occupy such a position in protein structure networks. As the complexity of the system increases, the mobility of creative elements expands, and covers more and more the entire network. Creativity emerges as a general concept helping crisis survival and evolution.