I hate to be the wikipedia poster here, but the entry on Biological Immortality does make for a good read in this context; https://en.wikipedia.org/wiki/Biolog

I hate to be the wikipedia poster here, but the entry on Biological Immortality does make for a good read in this context; https://en.wikipedia.org/wiki/Biological_immortality https://en.wikipedia.org/wiki/Biological_immortality