In this video from the NOVA series, Decoding Neanderthals, Wil Roebroeks and Friedrich Palmer try to replicate the Neanderthal technique of pitch extraction, a complex process called " dry distillation." Pitch was used by the Neanderthals to attach spearheads to throwing shafts. While the scientists were able to produce only a very small quantity of pitch, it shows that the Neanderthals had evidently mastered a complex thermal process to invent the world's oldest-known synthetic material.