An organism's very form is a functional manifestation of its ancestor's evolutionary and its own developmental memory. A completely ordered universe, however, would be dead. Chaos is necessary for life. Behavioral diversity, to take an example, is fundamental to an organism's survival. No natural environment can be modeled in its entirety.
Approximation becomes essential to any system with finite resources.
Chaos, as we now understand it, is the dynamical mechanism by which nature develops constrained and useful randomness. And from it follow diversity and the ability to anticipate the uncertain future. There is a tendency, whose laws we dimly comprehend, for natural systems to balance order and chaos, to move to the interface between structure and uncertainty. The result is increased complexity. This often appears as a change in a system's computational capability.