I wouldn't say arrested developement. like you said, the whole pricipple of eveolution up until modern science was survival of the fittest. Through this, stronger, smarter people or animals evolve that are best suited to their environment. This can be seen as true all through the world, so I don't think that blacks can be seen as arrested or more advanced than whites. We were just made for different lifestyles. White people are not suited to be living in a equatorial environment without adequate shelter. the black skin is well suited for that. White people evolved in a cold and often dark place, body hair is more prevalent, while male pattern baldness is a mainly caucasion trait because thhere was no longer the need for sheilding on our head from the sun. Lung capacity as well. Most africans were at low levels, where the air was thick. In Europe there were mountains and hills where the air was thinner and our lungs developed differently. This is a reason why many pure or mostly pure Africans do not float, and do not usually make good swimmers. Their lung capacity doesn;t hald enough air to make them lighter than the water. You can also see this in just the last 10,000 years or so when asians crossed into the americas. Some went down to warmer climates where they ended up smaller than average, while some that stuck around in alaska ended up having a very high body fat content to give them extra protection from the cold. Yet they do not suffer the same bad health effects from being fat tthat someone that is not from there would with the same fat content. It is all adaptation to environment. This is now going to stop and reverse becasue of things like eyeglasses and medicine. The weak no longer die, they are taken care of and allowed to produce with other weak people to have weak babies. Genetically the entire human race will backslide in evolution. And we will maybe compensate for these things, but in the future, maybe just 1000 years from now, just about everyone will have diabetes in their family, cancer, poor eyesight, artheritis, etc. Most of these people thousands of years ago would die early, usually before reproducing, this kept the human genes strong. The difference between black and white is no different that a lion and a tiger. Same idea, but brought up in different environments and time specialized them to where they lived. Doesn;t make one better than the other.