The ability to regrow body parts is dormant in mammals, not lost • Hacker News Board

Re: The ability to regrow body parts is dormant in mammals, not lost

#41

Post by malfist » Sat, Jun 20, 2026, 9:03 PM UTC

buddhistdude wrote: post #32

kennyadam wrote: post #30

Earlier quoted context omitted.

I think to claim that 2000 years ago there was one person who performed miracles and/or healed people that nobody else could, with no actual evidence it was done and nobody else has been able to do it since, you need a better response to someone questioning it than “oh were you there? prove it didn’t happen.”

No I don't because I'm not claiming that I know that it happened

What can be asserted without evidence can be dismissed without evidence. There was no Jesus who performed miracles of healing

Re: The ability to regrow body parts is dormant in mammals, not lost

#42

Post by abroadwin » Sat, Jun 20, 2026, 9:18 PM UTC

buddhistdude wrote: post #12

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

Judge not, lest ye be denied CRISPR.

Re: The ability to regrow body parts is dormant in mammals, not lost

#43

Post by RajT88 » Sat, Jun 20, 2026, 9:31 PM UTC

lazyasciiart wrote: post #7

ranger_danger wrote: post #4

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

I recall reading a similar story with powdered lizard. Also just a fingertip.

Re: The ability to regrow body parts is dormant in mammals, not lost

#44

Post by themafia » Sat, Jun 20, 2026, 10:07 PM UTC

cortesoft wrote: post #14

csr86 wrote: post #11

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 doubl…

Ah, I was wondering the evolutionary reason why those genes would have gone dormant. Cancer is a sensible answer.

Teratomas are insane.

https://en.wikipedia.org/wiki/Teratoma

Re: The ability to regrow body parts is dormant in mammals, not lost

#45

Post by 12_throw_away » Sat, Jun 20, 2026, 10:08 PM UTC

gste wrote: post #39

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)

Re: The ability to regrow body parts is dormant in mammals, not lost

#46

Post by casey2 » Sat, Jun 20, 2026, 10:14 PM UTC

buddhistdude wrote: post #24

krapp wrote: post #23

Earlier quoted context omitted.

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

How do you know?

Because I was there?

Re: The ability to regrow body parts is dormant in mammals, not lost

#47

Post by flir » Sat, Jun 20, 2026, 10:41 PM UTC

ck_one wrote: post #17

anticensor wrote: post #3

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.

Does that mean zebra fish with their ability to regrow the retina get cancer at a higher rate?

90 day life cycle. Rare for them to live over a year in the wild.

Re: The ability to regrow body parts is dormant in mammals, not lost

#48

Post by wafflemaker » Sat, Jun 20, 2026, 10:53 PM UTC

api wrote: post #37

cortesoft wrote: post #14

Earlier quoted context omitted.

Ah, I was wondering the evolutionary reason why those genes would have gone dormant. Cancer is a sensible answer.

Some aging mechanisms like telomeres are also mechanisms to prevent cancer by limiting cell division. It looks like one of the optimization edges walked by evolution is a conflict between longevity and the ability to repair and regenerate versus not getting cancer. It’s easy to make human cell lines immortal, but that will kill you. One route I can imagine to radical life extension is to start by editing the genome t…

I've learned about the cancer vs tissue repairability (or cancer vs heart/cardiovascular failure) from Joe Rogan's podcast with Bret Weinstein (or his brother, don't remember).

It's visible in death causes - pretty much all non accident deaths are divided between cancer and heart attack.

A very interesting thing discussed in that podcast was about transgenic (or maybe all?) lab mice bred in USA. These mice are used for initial screening for nearly all drugs. And due to some error and ignorance, unbeknownst to most people using the mice, nearly all mice are predominantly on one side. (Sorry, don't remember which). They just all come from the same family.

Which means that nearly all drugs in the past few decades are skewed toward either giving people cancer or heart attacks.

This is due to mice being extra resistant to one of these and therefore not properly signaling when the drug is likely to give people heart attacks or cancer.

Sorry, don't remember which it is exactly.

Re: The ability to regrow body parts is dormant in mammals, not lost

#49

Post by wafflemaker » Sat, Jun 20, 2026, 11:10 PM UTC

delfinom wrote: post #9

KellyCriterion wrote: post #6

Earlier quoted context omitted.

2 years I ago I sliced maybe 1.5mm frommy thumb-tip; when taking off the bandage, I could clearly see the "straight cut" and that some material was missing. Until today, it recovered completely

Lol, I once sharpened my knives and went to cook. During the prep I said, "wow I wonder how sharp the knife is", next thing you know, i cut about 1/4" of my finger tip off, right through the finger nail with zero resistance. Besides the blood getting everywhere and needing superglue to stop it, it grew back completely fine.

You shouldn't really sharpen kitchen knifes too sharp. And even if they're not super razor sharp (cutting a finger with no resistance), you should still warn people new to your kitchen or even family members/regular users right after each re-sharpening.

Additionally, too low angle will make the knife very suspectible to blunting and/or require constant drawing on the sharpening steel¹. Unless you have super high quality steel like Japaneese knifes or some craft smith knifes.

Butcher knifes, to be used along with a chainmail glove, are fine. Just don't test their sharpness on body parts. Or use them to shave a bit of hair, but very carefully.

1: https://www.dick.de/messer/en/sharpening/dickoron-family/dic...

Re: The ability to regrow body parts is dormant in mammals, not lost

#50

Post by LooseMarmoset » Sat, Jun 20, 2026, 11:31 PM UTC

malfist wrote: post #41

buddhistdude wrote: post #32

Earlier quoted context omitted.

No I don't because I'm not claiming that I know that it happened

What can be asserted without evidence can be dismissed without evidence. There was no Jesus who performed miracles of healing

even the Jews of the time that did not believe or follow Jesus wrote that he performed signs. They claimed it was sorcery.

in Folio 43a of Tractate Sanhedrin of the Babylonian Talmud as follows:

‘It is taught: On the eve of Passover they hung Yeshu and the crier went forth for forty days beforehand declaring that "[Yeshu] is going to be stoned for practicing witchcraft, for enticing and leading Israel astray.”’

The relevant portions of the Bible record that the Jews of the Sanhedrin acknowledged the signs and miracles but said it was by the power of Satan that he did these things.