Archaeologists have unearthed relics that suggest prehistoric humans lived along the Silk Road long before it was created about 2,000 years ago as a pivotal Eurasian trade network. An excavation project that started in 2010 on ruins in northwest China's Gansu Province has yielded evidence that people who lived on the west bank of the Heihe River 4,100 to 3,600 years ago were able to grow crops and smelt copper, the researchers said. The site is believed to date back to the Han Dynasty (202 BC - AD 220). Over the past three years, archaeologists have discovered a variety of...