Intelligence, by definition, evolves. Intelligence is not consciousness. Consciousness is not something that switches on at a certain number of neurons. If Slime Molds are permitted as evidence, they have no neurons, they have situational awareness, they have memory, and learn.

Consciousness is the foundation of all life, and all beings share this. I would go further and also reflect Native American spirituality which finds even the rocks and streams are alive is evidence consciousness is not limited to 'organic' molecules. There can be no distinction between things when it's all one. Nothing whole exists without its constituent parts.