I have not read the book, but it seems to me that there is an epidemic of infectious political correctness involved.
I can see the variations in the races, some for resistance to the sun in Africa, the heart of mankind. Some for absorption of sun to make Vitamin D as in the northern races. These show as differences in skin color.
We know that the most frequent winners of Marathons come from an area in Africa - Kenya, and so on. careful analysis of the DNA of these people will see what this is.
Similarly races all over the world have adapted to their local environment. In the far North, the enemy is the climate, the unremitting cold, which prevents unaided survival and the Inuit have developed a technology and a society that together allow survival.
In Africa, the climate is warm, and the enemy comes from other large predators, and from the largest predator of all - man. African societies have evolved to create a society and a technology that allows for survival.

In both these cases, the social nature of the people are very different. The tribal Inuit look on all other Inuit as kin and readily exchange wives to prevent inbreeding caused by isolation, thus Inuit have no wars and fight over no women.
In an African tribal milieu, the enemy is likely to be another tribe as well as predators, and so African have evolved to deal with them. Is this by greated battle readyness than the Inuit? An inbred protective aggressiveness? It may well be.

We are all kin, but we do vary, and all manner of measurable aspects of mankind can be expected to vary from place to place, much like Darwin's finches, they have evolved strengths that will win their battle for survival in their area.

Was not Archimedes killed by a Roman? His brain was of little use to him at that juncture. Races might have optimised their brains for kinetic skills in Africa - the only way to survive.
The persistent persecution of Jews may well have presented them with an opportunity to develop ways to solve their problems by intellectual processes = the Nobel winner ratio?

We can not make some aspects of human capability taboo by way of Political Correctness, we need to know and understand all of it.