It isn't us that is intelligent but the collection of our cells that are intelligent. If your to say that a cell is not intelligent then we aren't intelligent either. So to say that a neuron is no more intelligent than a cell located on my finger. They just have different jobs, don't discriminate, lol. When we see the system we see intelligence emerging like a colony of ants as another example that has been brought up.
Our system evolved over a very long time. Read the transcript here and some other interesting things on that site.
NOVA | What Is Intelligence?
But you said
"When a system
emerges it is a sign of intelligence"
So that system didn't just emerge.
I don't really mean consciousness but it may be related. At some point an organism acts rather than reacts and perhaps is able to think about what is being done. I'm attempting to illustrate that the basic functionality of our body isn't all that intelligent without the collective. Lifeforms are machines doing what they were born to do but intelligence is just a complex version of the machine like functions already possible in every cell.
It is very related.
"At some point an organism acts rather than reacts and perhaps is able to think about what is being done.'
Then you need a nervous system and conciousness.
NOVA | The Electric Brain
Learning is always a good thing for an organism to be able to do. Read and write.