• Energy Research

Analyzing coexistence and survival scenarios of Lotka-Volterra (LV) networks in which the total biomass is conserved is of vital importance for the characterization of long-term dynamics of ecological communities. Here, we introduce a classification scheme for coexistence scenarios in these conservative LV models and quantify the extinction process by employing the Pfaffian of the network's interaction matrix. We illustrate our findings on global stability properties for general systems of four and five species and find a generalized scaling law for the extinction time. 5 pages, 3 figures

Significance Biological active systems like swimming bacteria or molecular motors in the cell cytoskeleton consume energy locally to create movements or stresses. Although the surrounding fluid gives rise to thermal fluctuations of the system’s dynamic variables, the corresponding statistics can deviate significantly from a thermal Boltzmann distribution. To quantify these differences, we compare the statistics and dynamics of actin filaments driven by molecular motors with Brownian filaments. In both cases, energy injection is local and random; however, for active filaments, motors can generate sudden jump-like changes in the system’s dynamic variables, leading to nonequilibrium energy dissipation. Motor activity results in a nonthermal distribution of filament curvatures and a faster relaxation of filament bends than in the thermal case.