While UV rays can cause skin cancer, because skin cancer usually affects people after they have had children, it likely had little effect on the evolution of skin color because evolution favors changes that improve reproductive success.
The only problem was that I couldn't remember where I had heard that. In fact, I wasn't all that sure that I was right. I know that the Roman Empire lasted rougly 500 years but how about the Egyptians, the Chinese, the Ottomons, etc. I thought that it would be interesting to explore different empires and see how long they lasted. In another article, I talk about the definition of civilization..
Roman Empire. territory controlled by ancient Rome. The Romans built up their empire through conquest or annexation between the 3rd century BC and the 3rd century AD. At its height, the Roman Empire stretched from north-western Europe to the Near East and encompassed all the lands of the Mediterranean.