Neanderthals and other early humans produced a tarry glue from birch bark; this was long considered proof of a high level of cognitive and cultural development. Researchers had long believed that birch tar—used by the Neanderthals to make tools—could only be created through a complex process in which the bark had to be heated in the absence of air.
Click here for original story, Neanderthal tool-making process may have been simpler than previously thought
Source: Phys.org