So if you could do me a solid, in 500 words or less, what's changed about the state of the art since Dolly the Sheep? My understanding was that the shortened telomere problem was kind of a full-stop. I'll see if I can find the study. It may take a bit.
To be honest, I'm not very up to date on cloning. I could take a look a it. However, here in cancer research we are very familiar with telomorase running amok, where the ends never terminally shorten. AFAIK one of Dolly's suspected problems was that the telomeres had already substantially shortened, and they either picked up shortening more at that point, or the telemorase wasn't making up for what had already been lost. But all cells can express telomerase with the right cues, and a number of adult cells do. TBH I'd bet that Dolly had a number of other problems due to a previous life that simple nucleic transfer didn't reverse. Biology is crazy dirty. There rarely seems to be one problem or one solution. Typically the best you can do is to get the body to start doing the thing that you want it to, and let it go with broad guidance. My guess is we will figure out some slick ways to add a few decades, and then a few more, then a few more...
I am a ghost. all of this is a misapplication of Moore's "law" and I think the creation of a faulty metric we call technology. We are treating it as a vector when it is better modeled as a branching bush. It full analogy with the ladder of evolution vs the tree.
R. Buckminster Fuller said "I seem to be a verb". I think he meant something like this. I am not this blob of matter; not really. That is a slice, a snapshot of me. I am a pattern, a knot of information, moving through time. An incredibly complex knot, made of many smaller, microscopic knots, working together. My parents, who were similar knots, managed to split off tiny portions of their knots or patterns, and combine them into a new knot (actually they did this a lot, but only a few knots survived for a long time; at least four have still not unravelled. Eventually all knots unravel. Someday we may know enough to prevent it (would that it were so!). All our knots - yours, mine, the cat's - have survived to this day because it is the nature of our knots to tie new knots. This is life itself.