Whether or not there are differences in populations in terms of ability, though, completely misses the point. Let me briefly digress to make that point.
Let's say that all you've known of transportation technology is bikes. You see a group of people standing around and you're asked to predict who will get to the next town the soonest. You "know" that men tend to be stronger than women, that young men are stronger than old men, and lean men are faster than fat men. So you spot the youngest, leanest man in the group and point to him. "He'll be fastest," you say.
What you don't know from your little slice of time in 1880 is that you are now in a time when there are bikes, cars, bullet trains, planes and zip line infrastructure built between towns. As it turns out, an elderly lady with a cane and more money than the rest has hired a helicopter to get her to the next town and arrives there ten to 45 minute faster than anyone else.
Given technology advances, all the usual determinants are made irrelevant for predicting outcomes. The strong young man and the weak old woman move at exactly the same speed on the 767 jet and both are moving much faster than Usain Bolt ever ran.
Which takes me back to social realities that are most often equated with economics.
At one point in time, physical strength makes the biggest different in one's productivity. At the next stage of development, the ability to quickly calculate numbers is the biggest determinant. At the next it is creativity. And so it goes. As machines and systems at turns obsolete, automate, and enhance our skills, different "natural" skills matter more or less.
I put "natural" skills into quotation marks because as we learn more about genetic engineering and enhance tools like CRISPR that enable genetic engineering, even genetic differences at birth will matter little at determining our "natural" set of skills.
Progress is about creating better systems to enable us to enjoy life. "All men are created equal," is such a brilliant line because it shifts the focus from the question of whether one is an aristocrat or peasant and the argument of how different such people may be to the question of how we engage in social inventions to make everyone happier and more prosperous.
Racists focus on the wrong thing. Genetic evolution hasn't been a determinant of progress for hundreds of thousands of years. Social evolution is what makes Norwegians more affluent than Greeks, not biological evolution. The question of how quickly we get to the next town is a question of technological invention The question of how prosperous, peaceful and long we live is a question of social invention; do we have the right education systems, financial systems, business systems, and healthcare systems to enhance our lives?
That question matters to progress; the question of race does not.