You misunderstand "evolution" if you think of it as a (deliberate) linear process from "worse" to "better".

"Evolution", when applied biologically, is a theory of how organisms change over time by adapting to changing environments and circumstances. There is no "better" or "worse" about this except as said organism is fitted to its environment.

And it certainly has nothing to do with either "purpose" or "morality". 

 @8847b20e Minor tweak to correct observation - fundamental laws push this evolutionary process to more complex results, changes toward more complex are physically "preferred " to less complex. Hence the evolutionary arrow toward more and more complex organisms.