“…The concept of the "shadow system" was first proposed by Keener [17] in 1978. Since then, it has been extensively studied, and most of the research focuses on the existence of non-constant steady states (see, e.g., [14,15,22,23,24,28,29,32,40]), the stability and the instability of the non-constant positive steady states (see, e.g., [10,22,24,28,29,31,40]), the Hopf bifurcations (see, e.g., [28,39]), the compact attractors and the existence of monotone solutions (see, e.g., [12,18]), the global existence and boundedness, finite time blow-ups of the in-time solutions (see, e.g., [9,19,21]), the spectra of the linear diffusion operators related to the shadow system (see, e.g., [20]), and the dynamics of the stochastic shadow system (see, e.g., [41]).…”