Delay effect in models of population growth

Abstract. First, we systematize earlier results on the global stability of the model ẋ + μx = f(x(· − τ)) of population growth. Second, we investigate the effect of delay on the asymptotic behavior when the nonlinearity f is a unimodal function. Our results can be applied to several population models [7, 9-13] because the function f does not need to be monotone or differentiable. Specifically, our results generalize earlier result of [8], since our function f may not be differentiable.