Guy, this is the stupidest thing I've heard yet.
It's pretty clear you don't understand how evolution works.
The way evolution works is that innate characteristics that increase the likelihood an organism will survive and reproduce expand in a population of that organism.
Cold climates select genetically for intelligence and monogamy. It takes more intelligence to survive in a cold climate. Women cannot do it without the help of a man.
Civilization selects genetically for intelligence and law obedience. Intelligent men usually prosper and have more children who live to adulthood. Criminals are usually killed at the scene of the crime, they die in custody, or they are executed. The few children some criminals have rarely live to adulthood.
This is the way things have been until comparatively recently. Welfare checks and other anti poverty programs enable the unfit to have more children than intelligent, law abiding people. This is dysgenics. The solution is eugenics.
The environment in sub Saharan Africa did require some intelligence. If it did not Negroes would not have become more intelligent than chimpanzees. Nevertheless, it required less intelligence than cold climates and civilizations.
In a tribal environment all men fight in the wars. The best warriors have more than one wife, and more sons who inherit violent inclinations and abilities.
Moreover, with no government, men are expected to avenge wrongs done to them, their relatives, and their friends. Women do not become involved with men who refuse to do this.
Civilization selects genetically against physical aggressiveness; a tribal environment selects for physical aggressiveness.
Keep in mind that I am describing average differences, rather than absolute categorizes. There are Negroes who intelligent, monogamous, and law abiding, just as there are stupid, promiscuous white criminals.