Abstract

In the Technical Comments section of Science, Perry et al. argue that the claims of chaotic population dynamics made by Costantino et al. (1997) must be shown to be "robust to the presence of noise." They also call for Costantino et al. to compare their data to the output of the stochastic version of their model. In reply, Desharnais et al. report the stochastic Liapunov exponents of their LPA model, which, like the deterministic Liapunov exponents, indiciate chaos. They also present a comparison of the experimental data and output from the stochastic LPA model. Desharnais et al. go on to contrast their approach to the methods suggested by Perry et al.