The researchers also found that the next technological revolution, marking the beginning of the Middle Stone Age happened tens of thousands of years earlier than previously thought. Gap in the evidence 
 
 Across Africa, the Middle Stone Age is characterised by the absence or rarity of large cutting tools and the presence of prepared core technologies for making sophisticated points and blades. Back-and-forth shifts from dry to wet conditions — many happening over only a few years or decades — continued to regularly reshape the Olorgesailie landscape around 320,000 years ago, conclude Potts, of the Smithsonian Institution in Washington, D.C., and colleagues in another of the new papers. Now, three new papers, published in Science, show that technologically advanced behaviours occurred much earlier than we thought in the African stone age. Crucially, the transition between the African Early and Middle Stone Age occurred around the time that our own species, Homo sapiens, was evolving across the continent. Elsewhere across Africa, the association between Early and Middle Stone Age and pre- and fully-modern human fossils remains complex and confusing. The team therefore classified them as Middle Stone Age industries. Some of those finds display signs of having been attached to handles, likely as spearpoints, a group led by archaeologist Alison Brooks of George Washington University in Washington, D.C., reports in the third paper. At one Olorgesailie site in particular, 42 percent of more than 3,400 stone artifacts were obsidian. "In the Middle Stone Age, we begin to see the early stages of social networks, of being aware of another group and exchanging rocks over longer distances." Obsidian wasn’t the only exotic material – they also discovered bright red ochre pigment displaying evidence of grinding and cut marks, which makes this among the oldest known pigments used to colour rocks in the archaeological record.
– For decades, the human story was one told through signs of modernity—art, tools, burials—found only after Homo sapiens left Africa. Recent discoveries pushing back the date of departure are helping to change that narrative, as are three new studies in Science. Together, they describe the earliest stone tools of their kind in East Africa as well as the earliest evidence for long-distance transport of raw materials in the region, per Science News. Researchers previously believed the Early Stone Age marked by large, primitive tools (hand axes and cleavers) made way for the Middle Stone Age and its smaller tools (spearpoints and blades) around 280,000 years ago. But stone tools found in Kenya's Olorgesailie Basin show hominin groups—it's not clear which species is responsible—had developed these more advanced tools approximately 320,000 years ago. "We see a smaller technology, a more diverse series of stone tools … designed for specific purposes," researcher Rick Potts tells NPR. An expert not involved in the study says the tools are so "prepared and retouched" they suggest the Middle Stone Age likely started even earlier. What drove it? Microscopic and chemical analyses of the region's soil show the landscape was rapidly shifting between wet and dry conditions, meaning hominins might have been forced to adapt. But as the technology also coincides with the emergence of Homo sapiens in Africa, it's possible that the human mind deserves credit. The tools themselves suggest the development of trading networks, too. Some were made of rocks carried from 55 miles away, says Potts. Others were made of obsidian from as far as 30 miles away, per the Conversation. (These stone tools are also making waves.)