Making birch tar at all is a fairly complex process. It takes multiple steps, lots of planning, and detailed knowledge of the materials and the process. ... Mak

Making birch tar at all is a fairly complex process. It takes multiple steps, lots of planning, and detailed knowledge of the materials and the process. ... Making birch tar adhesive for tools was so routine that Neanderthals would do it even for a simple domestic tool like a small flake ... “The Neanderthal tar finds provide evidence of a complex technology so ingrained in their behavior that it was maintained at the limits of their ecological tolerance: glacial northwestern Europe.”