We just want AI to be able to think. We do not need an AI with an autonomic nervous system, or many of the functions in the central nervous system. We do not need AI to be very power efficient. If it takes several megawatts of electricity to get our first strong AI working, so be it.
So, we do not have as many constrains as life did.
That is the most impressive use of the word 'just' in a long time. Note that all the other bits are solved, and have been solved since the 60's. It's the 'just think' bit that has proven to be a little bit harder than we thought it would be.
The embodied cognition folks believe that the embodiment of sentience affects cognition.
That is probably true to some extent. I mean, if we make an AI that has an orgasm each time it blows up something with a hellfire missile, it will probably learn to find ways to blow up more things more frequently and efficiently.
Our cognition is affected by pain, hunger, thirst, cold, heat, pleasure, smells, sounds, etc... positive and negative reinforcements.
So, we do not have as many constrains as life did.