Phases and phase transitions in living matter

Abstract

Standing on the shoulders of giants such as Landau, Anderson, Mandelbrot or Bak, emergent phenomena have meant a major step towards the comprehension of macro-structures and patterns in Nature. In particular, the criticality hypothesis, which proposes that –under some circumstances– living systems can lie in the vicinity of a phase transition, i.e. at the borderline between their ordered and disordered phases, has shed much light on the comprehension of several natural phenomena that, until recently, were poorly understood. This celebrated and provocative idea conjectures that living close to a critical point may confer a large number of benefits such as maximal dynamical range, maximal sensitivity to environmental changes, as well as an excellent trade-off between stability and flexibility. Based on this assumption, the aim of this thesis is to look into the criticality hypothesis, extending its horizons through the analysis of phases and phase transitions in Nature, developing a better understanding of certain empirical findings and behaviors of biological systems. Thus, the development of models trying to shed light –through numerical simulations and theoretical calculations– on the emergent behavior of particular biological systems constitute the common theme of this thesis.