AI machines will never be truly alive in the sense of biological organisms, not until they show autopoiesis — continual re-creation of their own cells and tissues, a daunting proposition for any engineer. To ignore this meta-stable aspect of the intelligence of organisms — that they can retain form and function while being composed of different matter from one moment to the next — is to fumble back to the irrelevance of many biology courses that fail to address this aspect of the “magic.” Of course, it’s not magic, bur rather sophisticated information processing directing the biochemical processes that regulate the rate of matter turnover in different cells and tissues. While the skin quite obviously turns over whole cells, the brain probably does not, but neurons do indeed turn over their constituent proteins, etc.