Evidence from a cave in eastern Ethiopia has revealed something extraordinary about the origins of symbolic thought among humans. Forty thousand years ago, Porc-Epic Cave was surrounded by lush grassland full of lakes and rivers. It was home to a thriving community of people who devoted considerable time to processing ochre, a reddish powder used for a variety of things including paint. Writing in PLoS One, anthropologists Daniela Eugenia Rosso, Africa Pitarch Martí, and Francesco d’Errico describe how they worked with the National Museum of Ethiopia to analyze these Middle Stone Age people's ochre-making tools. What they found was that this workshop's artisans produced a far more complicated array of substances than anyone had understood before. Some were used for art and decoration, and others were used for engineering better weapons.
Anthropologists often use ochre processing as a proxy for the origins of human symbolic thought. That's partly because ochre is relatively difficult to make, requiring a few steps and at least two kinds of tools. As the researchers write, ochre comes from "rocks containing a high proportion of iron oxides, often mixed with silicates and other mineral substances, which are red or yellow in color, or are streaked with such shades." Ochre itself is made by pulverizing the rock with one kind of tool and then reducing it to a powder between two grindstones.
There are many aesthetic uses for ochre, including as fabric dye, paint for cave walls, or a stain for rocks and other materials. All these artistic or cosmetic uses imply symbolic thought. But early humans used ochre for utilitarian purposes, too. The powder was mixed with other adhesives to keep weapons snugly attached to their hafts. Put simply, ochre was a key ingredient in glue.
The question that has long raged among archaeologists is whether people first began using ochre as a tool for engineering or as a substance for making art. In other words, does symbolism start with science or aesthetics? By examining 23 ochre-processing tools from Porc-Epic Cave, researchers figured out that the answer is that both emerged at the same time, in the same workshops....
While I understand that from a scientific POV there has to be the evidence, before anything definitive can be stated, about anything. I always get a little annoyed with the train of thought that assumes humans aren't smart enough to have come up with idea x or y, even as far back as 100000 years ago, when our subspecies (Homo Sapians, Sapians) had become dominant. That kind of thinking invariably leads to the creation of gods who gave us the knowledge of aliens that came to earth and taught us. The fact is there is no reason to believe we are not smart enough to have worked it out all by our selves.