If you mean tech/culture/language capable, well it isn’t surprising that has only happened once, because it is so recent, and the first tech species tends to takeover the planet and preclude others.
If you mean something more like “near human problem solving capability”, then that has evolved robustly in multiple separate vertebrate lineages: - corvids, primates, cetaceans, proboscids. It also evolved in an invertebrate lineage (octopi) with a very different brain plan. I think that qualifies as extremely robust, and it suggests that evolution of culturual intelligence is probably inevitable, given enough time/energy/etc.
Depends on what you mean by ‘intelligence’.
If you mean tech/culture/language capable, well it isn’t surprising that has only happened once, because it is so recent, and the first tech species tends to takeover the planet and preclude others.
If you mean something more like “near human problem solving capability”, then that has evolved robustly in multiple separate vertebrate lineages: - corvids, primates, cetaceans, proboscids. It also evolved in an invertebrate lineage (octopi) with a very different brain plan. I think that qualifies as extremely robust, and it suggests that evolution of culturual intelligence is probably inevitable, given enough time/energy/etc.