OK, Abbreviation. I’m looking at archaeology now. If a child of three can understand Wild Apple Leaves, Gravettian, Solutrian, and Magdalenian cave men likely had them figured out too. Being in caves, they likely used fire for light as well. Dr. is an abbreviation for “Dumber” is all I can figure out from the evidence of their performance track record. Dumber than cave men. As evidence, just ask one for a light. A cave man gives results. Modern man has been neurologically attacked by filarial nematodes for millennia since the last ice age at least no doubt, and there is no recovery in sight. We have de evolved from the Upper Paleolithic stage of Man.
Most of what we know about cave men is from their art and tools found at preserved locations. 20,000 years ago, the latest Ice Age melted off.