Could it not be possible that snakes are evolved and are evolving to be the best venom producers? Elephants are evolved and evolving to become the biggest bodied organic creatures? Etc.
Not that I am trying to assign a life purpose to the animals or to humans, but just a question I'd in my mind.
I agree that humans might be most evolved to make use of the logical brain, but isn't it the humans themselves who have given so much importance to logic.
More seriously, "most" implies a direction that we conveniently orient in ways that make humans seem superior. In my experience, linguists are particularly guilty of this type of thinking -- language is something that 'only' humans can do. What, prairie dogs can communicate semantic content using their voice? Hold on while I move the goalposts...