We humans are not as we are by accident. Whether you believe intelligent design or evolution, or a bit of both, we are so perfectly adapted for what we do (yes we choose to do many things that require physical protection from the elements but that's just because we can). Think about it. In order to be the creators, designers, engineers, that have developed the world and its materials in the way that we have, not having hands with opposable thumbs, or a different amount of fingers on each hand, or less or more hands, arms, legs, or feet, and the way they each do their job, would mean we probably would not be the kind of beings we've become as the brain would have no need to develop in quite the same way in order to evolve the skills it has. That's why the idea of what a similar or more advanced alien species might look like, disregarding gravitational influences affecting overall size and shape, must still bear some resemblance to us. Of course, there are such a wide range of strange looking creatures all around us on planet Earth that it's understandable why we might imagine intelligent alien life would probably look very different to us, but all the other animals (primates excluded) could never do what we do, whether they were 'intelligent' or not because their body structure just wouldn't allow them to manipulate the world in the right way. Thoughts?