That's a fascinating question! First, it raises the idea that human intelligence may actually decrease over time, especially as we offload our thinking to machines. It's hard to tell whether that will increase or decrease our intelligence or leave it roughly the same. I have a hunch, and it's just a hunch, that our intelligence will increase over time.

With regards to dolphins and crows - wow! What a find animals like that would be on another planet! Quite intelligent - but not technologically advanced. You raise an interesting question: assuming a planet has evolved life having the intelligence of a crow or dolphin, what's the probability that planet will evolve a technologically advanced life form? How likely is it earth is the only planet to have evolved such a life form?