The oldest evidence of silk made by silkworms has been found buried in 8,500-year-old tombs in China, revealing that people may have used the luxurious material thousands of years earlier than previously thought, a new study finds.
Silk was a rare luxury good in the ancient world. Its fame helped give a name to the Silk Road, the legendary network of trade routes that once connected the East and West from China to Rome.
The secret of how to make silk was first discovered in China. According to Chinese legend, after a silkworm cocoon dropped into the teacup of the wife of the Yellow Emperor, she found that the cocoon could unravel to yield about 3,300 feet (1 kilometer) of thread.
To learn more about the origins of silk, scientists investigated ruins dating back 9,000 years at Jiahu in the middle of Henan Province in central China. Previously at this site, scientists had unearthed bone flutes that are the earliest known playable musical instruments on Earth, as well as what may be the earliest Chinese writing. [In Photos: Ancient Silk Road Cemetery Contains Carvings of Mythical Creatures]
Old tales suggested that silkworm breeding and silk weaving began around this area, said study co-author Decai Gong, an archaeologist at the University of Science and Technology of China at Hefei. In addition, prior work at Jiahu revealed that the area's warm and humid climate favored the growth of mulberry trees, whose leaves are the sole food of silkworms.
The scientists collected soil samples from three tombs at Jiahu. Chemical analyses revealed evidence of silk proteins in two of the three tombs, one of which dated back 8,500 years. This is "the earliest evidence of silk in ancient China," Gong told Live Science. Previously, the oldest evidence of silk dated back 5,000 years from China, the researchers said.
Although it's difficult to figure out exactly how silk was used at this site, the researchers suggested that these people were perhaps buried in silk garments. Evidence supporting that idea came from bone needles and weaving tools found at the site, which suggested that "Jiahu's residents possessed basic weaving and sewing skills," Gong said. "There is a possibility that the silk was made into fabric."
In their future research, the scientists will hunt for other signs of silk at this and other sites, Gong said. He and his colleagues detailed their findings online Dec. 12 in the journal PLOS ONE.