Dr. Kaku always has an objective look and a realistic look when assessing the cosmos. For the most part he is a very positive fellow with a great sense of humor which is necessary in a field where all his peers are generally flat emotion types. Alien races needs are likely very different from ours. They might have transcended dimensions too so space and time mean nothing to them. When you look at the planet it is obvious it was designed to be an experiment of some sort. Everything on earth is consumed over time to make way for other species or advancements. There does not seem to be any favoritism to any species as even we are prone to die in any number of ways. I don't know what is out there but there is something. What that is will eventually over time become clear.