What do you expect humanity to achieve by a "pure quest for knowledge" about the physical and neurological differences between people? Yes, it's important for scientists to study those things, but you seem to be arguing that these differences could be a justification for some sort of caste system in which people are given different political rights based on their physical attributes. I don't see you placing any value on self-esteem or dignity. Those things have a huge impact on people's happiness and ability to realize their potential, regardless of how you "rank" their physical attributes. Why do you disregard them?
You also seem to imply that physical attributes have some kind of supreme existential value that supersedes other values like diversity or tolerance. What justification do you have to assign such value? Why can't I equally claim that the extinction of humanity would add value to the universe? I prefer a value system in which all people have a stake, not just the most physically superior.