Ha, good point. I suppose you could say that, assuming the 'arrow of evolution' always results in an improved adaptation to a living thing's environment, that any creature is the "most evolved" relative to the DNA history from which it stems. Then again, DNA mutations don't always result in positive adaptations to an individual creature's environment; sometimes (most often?) individuals degenerate relative to their predecessors.

So, maybe you can only fairly compare the degree of evolution between members of the same species functioning in generally the same environment and competing for generally the same resources.