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..
The city of Rome was taken over several times by barbarians, notably in 410 AD when the Goths sacked the city . The last Western Roman emperor, Romulus Augustus, resigned in 476 AD. The Roman Empire would last another 1,000 years as the Byzantine Empire in the east. The main coin of the Roman Empire was the silver denarius.