The fact that all dogs are descended from wolves does not mean that we can't categorize certain dogs as having features that match a pre-defined description of Basset Hounds or Poodles. The fact that some dogs look like a kind of a mix between a Basset Hound and a Poodle does not mean that we cannot define the difference.
That the difference between humans should be immaterial to the way a government treats someone, or the rights they are entitled to, or to their status in life should not negate an objective look at their differences. Why someone would want to persue such a scientific path is a different matter. The Nazis wanted to prove that Germans were superior. Most grants are given now in an effort to prove there are no differences when such differences clearly exist. Both are persuing a political end not a scientific one.
In the end we are all humans, with dreams, aspirations, and emotions. We all want the best for our children. We all want a government that treats us with equal opportunity yet preserves our ability to seize that opportunity to rise above the mean based on our own knowledge, skills, and abilities even if that equality of opportunity puts some individuals behind other individuals (regardless of race) in outcome.
Freedom. Free to succeed, free to fail.
Security. Safe from failure, safe from success.