Some 76 countries and territories use left-hand traffic, and the practice is believed to have originated in ancient Rome to help defend against enemy attacks. Following is a transcript of the video.

While such body art works can provide insights into ancient ... forearm (left) under laser-stimulated fluorescence, revealing hidden details of tattoo designs, and a mummified hand (right).

and left elaborate markings in far more than their tattoos, said Aaron Deter-Wolf, a prehistoric archaeologist at the Tennessee Division of Archaeology who specializes in ancient tattoos and was ...