Here's why:
* Cognitive capacity: Humans evolved the necessary brain structures for complex language around 200,000 years ago, well within the Paleolithic period.
* Social complexity: Hunter-gatherer societies required complex communication for tasks like hunting, gathering, resource management, and social interaction.
* Tool use and innovation: Sophisticated tool use, including projectile weapons and fire, points to abstract thinking and communication.
* Symbolic behavior: Evidence of cave paintings, burial rituals, and personal adornment suggests a capacity for symbolic thought and communication.
* Modern hunter-gatherers: Studies of contemporary hunter-gatherer societies demonstrate complex language systems, including rich vocabularies, grammar, and nuanced communication.
However, the extent and nature of Paleolithic language remain unknown. We can't be sure:
* What specific language families existed: While some evidence points to the existence of Proto-Indo-European, the picture is far from complete.
* The exact structure and complexity: Was it similar to modern languages, or simpler?
* Whether writing existed: Writing likely emerged much later, during the Neolithic period.
Overall, while we can't definitively reconstruct Paleolithic languages, the overwhelming evidence points to their existence. Future research will likely shed more light on these fascinating societies and their communication systems.