Retina is a good example of this. Zebrafish can regrow damaged retina, but while mammals have the same stem cells (Muller glia), they dont repair the retina, but form scar tissue. There is a lot of research and I think they have managed to modify rat genome, so that their retina has showns some repair abilities. The problem is that it often causes tumors.

I have other retina permanently damaged, and suffer from double vision when looking small objects like text.

I’m surprised this does not mention humans can grow back the tips of their fingers (past the white part of cuticle) https://www.npr.org/sections/health-shots/2013/06/10/1903854... Supposed to be only kids but I’ve chopped off a few mm by accident it came back as an adult or I can’t tell the difference.

Not a single mention of the work on limb regeneration by Professor Michael Levin's lab at Tufts?

https://as.tufts.edu/biology/tufts-center-regenerative-and-d...

In a study they figured out that organs seem to have an electrical potential range as a signature/command for stem cells for which organ to build and where.

In a frog they were able to grow legit eyes in the gut just by artificialy inducing a certain voltage in that area. No need for any cell transplantations: the voltage really seems to be the only signal needed.

This might also be how it might be done in the future in humans: block scar tissue then induce voltage with the signature of the organ you wish to regrow.

https://pubmed.ncbi.nlm.nih.gov/22159581/

The trick is to make regeneration fast enough to heal the wound without making fast enough to cause cancer. Maybe even supported by provisional fibrosis.

Whoa, sounds like your recommending some sort of healing mechanism like those human animals have

Same tradeoff we hit with early JIT compilers back in the 90s, optimize too aggressively for speed and you get instability. Salamanders probably tuned this over a million years, we won't nail it in one grant cycle.

It's just hidden by a feature flag.

(Probably for a good reason)

tbh I think it's probably just commented out (and is about as likely to still work as any other commented-out code)

Yeah, seen this in old firmware before - dead code paths that "just need a flag flip" turn out to be bit-rotted the moment you actually try running them. Wouldn't bet on regeneration genes being any different after a few hundred million years.

Evolution is so smart.

Smart enough to hide the cheat code from us, apparently.

I'm hoping that this can be applied to routine genital mutilation in humans that are often done near birth and without consent.

Wasn't this proven many years ago by a random guy who used a "extra-cellular matrix" of stem cells to regrow his severed finger, nail and all?

Found it: http://news.bbc.co.uk/2/hi/7354458.stm

No, the end of your finger just can grow back. https://www.npr.org/sections/health-shots/2013/06/10/1903854...

Dude's brother had him throw his product on the finger as it did so, definitely an astute marketing trick. https://www.theguardian.com/science/2008/may/01/finger.claim

The BBC piece was a single case report, not verified regeneration — distal fingertip regrowth via the nail matrix is well documented and unrelated to blastema-based limb regrowth researchers are actually chasing here.

Perhaps humans can one day regrow their teeth for better food ingestion when elderly and cognitive function.

Maybe that's what Jesus used on the people that he healed

In the whole Christian tradition, God/Jesus generally does not go for organ or limb regeneration. Two counter examples are a healed ear in Luke (but this may well have been resumption of hearing? details are a little light), and then a single Spanish example in the 1600s.

For His own mysterious reasons, He simply doesn’t go in for that stuff, however much intercessionary prayer ends up in His inbox.

Judge not, lest ye be denied CRISPR.

> Maybe that's what Jesus used on the people that he healed

I think this is what all healers used. They were all way ahead of their time and clearly misunderstood.

Jesus, if he existed, didn't actually heal anyone or perform any miracles. That's mythology, not reality.

Has anyone actually measured metabolic cost of staying regeneration-capable? Zebrafish are ectotherms with way lower energy budgets. Suspect the "dormant" switch got flipped off partly because warm-blooded metabolism can't afford it.