A kinetic scattering approach to the non-linear instabilities of rat brain tyrosine hydroxylase preparations at several levels of tetrahydrobiopterin cofactor demonstrates evolutionary behavior characteristic of global dynamical systems.

Statistical patterns from the time-dependent fluctuations in kinetic scattering of a complex rat brain tyrosine hydroxylating system reveal near periodic, quasi-periodic, and chaotic regimes that alternate in a non-linear manner across linear changes in tetrahydrobiopterin cofactor concentrations, a phenomenon characteristic of the initial condition- and parameter-sensitive evolutionary behavior of global dynamical systems.