Final answer:
The development of art was an important advancement in the early Stone Age, but it was one of many critical developments, not necessarily the most important. Art, along with tool use and the onset of agriculture, played a key role in the cognitive and social evolution of early humans.
Step-by-step explanation:
The ability to communicate through art during the early Stone Age was indeed an important development, but it might not necessarily be classified as the most important.
While the creation of symbolic language and the foundations for a shared culture were crucial advancements, other developments such as the ability to produce and use tools, the establishment of agriculture, and the domestication of animals were equally critical to human society's evolution.
The early Stone Age art provides insight into the cognitive and social abilities of our ancestors, indicating that they were capable of modern symbolic thought and complex social interaction.
Developments in the Neolithic period, such as sophisticated stone tools and the transition from food gathering to food production, allowed for permanent settlements and paved the way for advancements in societal structure.
Art depicted in the material culture of hominins like Homo habilis and Homo erectus stands as testament to their cognitive abilities, which are closely linked to the development of human language.
The emergence of art in the Middle Stone Age, such as the animal forms found in the Apollo 11 cave stones, shows that humans were not just anatomically modern but also behaviorally modern, possessing the capacity for symbolic thought long before the previously believed timeline.