Nonequilibrium evolution of volatility in origination and extinction explains fat-tailed fluctuations in Phanerozoic biodiversity

Fluctuations in biodiversity, large and small, pervade the fossil record, yet we do not understand the processes generating them. Here, we extend theory from nonequilibrium statistical physics to describe the fat-tailed form of fluctuations in Phanerozoic marine invertebrate richness. Using this theory, known as superstatistics, we show that heterogeneous rates of origination and extinction between clades and conserved rates within clades account for this fat-tailed form. We identify orders and families as the taxonomic levels at which clades experience interclade heterogeneity and within-clade homogeneity of rates, indicating that families are subsystems in local statistical equilibrium, while the entire system is not. The separation of timescales between within-clade background rates and the origin of major innovations producing new orders and families allows within-clade dynamics to reach equilibrium, while between-clade dynamics do not. The distribution of different dynamics across clades is consistent with niche conservatism and pulsed exploration of adaptive landscapes.

ON NONEQUILIBRIUM PHYSICS AND STRING THEORY

In this paper, we review the relation between string theory and nonequilibrium physics based on our previously published work. First, we explain why a theory of quantum gravity and nonequilibrium statistical physics should be related in the first place. Then, we present the necessary background from the recent research in nonequilibrium physics. The review discusses the relationship of string theory and aging phenomena, as well as the connection between AdS/CFT correspondence and the Jarzynski identity. We also discuss the emergent symmetries in fully developed turbulence and the corresponding nonequilibrium stationary states. Finally, we outline a larger picture regarding the relationship between nonperturbative quantum gravity and nonequilibrium statistical physics. This relationship can be understood as a natural generalization of the well-known Wilsonian relation between local quantum field theory and equilibrium statistical physics of critical phenomena. According to this picture, the AdS/CFT duality is just an example of a more general connection between nonperturbative quantum gravity and nonequilibrium physics. In the appendix of this review, we discuss a new kind of complementarity between thermodynamics and statistical physics which should be important in the context of black hole complementarity.