Selkov model — spiral waves and Turing instability patterns
The Selkov (1968) model of glycolytic oscillations: ∂u/∂t = Du∇²u − u + av + u²v, ∂v/∂t = Dv∇²v + b − av − u²v. This minimal 2-variable autocatalytic system generates spiral waves (oscillatory regime) and Turing patterns (diffusion-driven instability) depending on parameters.