If you think about it, that's evolutionary theory in a nutshell. Organisms don't evolve due to any desire or goal to change; rather, random processes cause mutations, and traits that happen to result in more copies of themselves being made tend to become more common, and that's it. There is no purpose to the changes; they just are, and "better" ones happen to become more common because they duplicate more.

I would argue that this just means that some things and processes, like evolution, do not have a purpose, rather than that their purpose is whatever actually happens. If purpose just means result, then you've defined purpose such that it no longer applies to lots of systems we actually already understand the purpose for.