When the conditions are right it’s just a matter of time before intelligence arises – just like life itself. I also think all life is ‘conscious,’ i.e., aware of its environment or it wouldn’t be alive very long.

You’re right about AI programmers using top-down approaches to simulate intelligence but that is not the same as creating a sentient being. To do that I believe programmers will need to introduce some sort of parasitic forces like we see in nature. It is the work of parasites that create a kind of arms race producing better and better organisms by way of natural selection. It’s a bottom-up process that naturally leads to intelligence.