Selective funnelling and state-space expansion: a conceptual framework for novelty generation and origin events

Evolution, conceived broadly as encompassing both biological and abiological systems, generates novel structures and phenomena that are seemingly different, in important ways, from what came before. While it is always possible, in theory, to describe complex systems using the language of the most basic physical entities and laws, it is almost never practical to do so. When novel systems arise, their behaviour may be better explained and predicted using new sets of properties and principles. How can we understand this universal aspect of evolution—that is, the tendency of a system to produce astonishing novelty? Here, we introduce two new concepts: selective funnelling and state-space expansion. Together, these processes describe the mechanisms by which an evolving system shifts from one functional fitness landscape to another. During selective funnelling, non-equilibrium features from the previous level are ‘locked in’, promoting the increase of functional information in evolving systems with time. A state-space expansion event is characterized by significant changes in components of relevance, driving forces for exploring combinatorial possibilities and/or selection mechanisms. Together, selective funnelling and state-space expansion provide an abstract framework for understanding a plethora of diverse origin events, trends of increasing ‘complexity’ in the universe and the challenging phenomenon of ‘emergence’.