Around 120,000 years ago, ancient humans in northern Israel came up with an idea to adorn their body: collecting, painting and stringing together naturally perforated shells to wear them as necklaces. A group of Israeli researchers shed light on this type prehistoric jewelry in a paper published in the open-access journal PLOS ONE on Wednesday. The development of the stringing technique might have also opened the way to many later technological evolutions, the scholars argued.The study is based on findings from different caves. Bittersweet clam shells amassed by humans dating back to at least 160,000 years ago were found in the Misliya Cave on Mt. Carmel, while the perforated shells were found in the Qafzeh Cave in the Galilee. “We speculate that the adornment was not only intended to express the feelings that humans had about the shells, but also to express tribal or class identity or affiliation with other populations,” Tel Aviv University archaeologist Daniella Bar-Yosef Mayer, a lead author of the paper, said in a press release.“The timing of the invention of strings is of significance beyond the desire to adorn oneself,” she added. “String-based technology allowed several additional significant developments related to human evolution, including the creation of hunting traps and fishing nets, archery for hunting with arrows, fishing using hooks, and other various practices related to sailing – for example, tying logs of wood to create rafts, as well as several uses connected to clothing. At this stage, we have no direct confirmation of the existence of these technologies in this ancient period, but microscopic evidence of the existence of plant fibers has been growing in recent years.”According to the release, Bar-Yosef Mayer and Iris Groman-Yaroslavski from the University of Haifa collected the same species of perforated clamshells and simulated the potential use and wear present on the original shells in a series of experiments on modern shells from the same species: first systematically abrading the shells against different materials like leather, sand, and stone to investigate patterns, then using strings made from wild flax to simulate hanging the shells on the human body and to identify were created on shells by suspending on a string.The researchers also found evidence that the shells were painted with ochre.