https://en.wikipedia.org/wiki/Race_and_intelligence
Besides all the serious concerns about the validity and interpretation of any claims that one 'race' (which is a social construct, not a biological one) has a higher IQ than another, this is what stands out to me:
Black Americans today have a higher IQ (on average) than white Americans two generations ago. Yet somehow our (lower IQ) grandparents managed to build and continue a thriving society with science, arts, and the whole shebang.
If our 'dumb white grandparents' could do it, surely any 'race' alive today can.
At for the quotes on subspecies and cleaning up the breeding area: they're both unscientific and immoral. Adolf Hitler made sure eugenics and Übermensch breeding was tainted forever.