Final answer:
Primitive ancestors used charcoal to create images on cave walls. This method evolved from simple line drawings to more complex art forms including the addition of natural binders and pigments. This artwork serves as a lasting testament to early human creativity and communication.
Step-by-step explanation:
A form of charcoal was used by our primitive ancestors to create images on cave walls. These early humans utilized the charred remains of their fires, a resource plentiful as it was a byproduct from cooking and providing warmth, to sketch out the world around them. With charcoal as a drawing tool, they created line drawings and sometimes filled these outlines with various pigments, sourced from elements such as ochre found in the environment.
Eventually, as they honed their craft, these cave artists incorporated other natural binders such as animal fat or bone marrow to create more durable paints. These mixtures adhered well to cave walls and have lasted through millennia, providing us with a window into prehistoric life. From concise symbols to more complex representations of animals, handprints, and possibly figures signifying fertility, their artwork tells a story of not only survival but also an early form of human expression and communication.