Persuading the Body to Regenerate Its Limbs
newyorker.com
newyorker.com
It seems to be a good time in the debugging of these complex pathways as there's another, related avenue of signal manipulation research that may lead to scar-less tissue healing (https://science.sciencemag.org/content/372/6540/eaba2374)
Those skills have served me well in my current work in debugging biological systems, where the organisms responsible for all these “clever” hacks are long gone, and all we’re left with is a system that often doesn’t boot back up after a crash.
What Bodies Think About: Bioelectric Computation Outside the Nervous System - NeurIPS 2018 https://www.youtube.com/watch?v=RjD1aLm4Thg
One fascinating thing about this work is that we have a subjective "interface" to the "technology" already. I wouldn't be surprised if it turns out that one can engender e.g. limb regrowth or bone-shaping using some kind of guided meditation.
Recall that the "3-Minute Mile" was a psychological, not physical, barrier. I think we're faced with a similar situation here: the only thing preventing us from learning to regrow limbs is the common belief that it's impossible. I find it curious that the very idea of researching limb and organ regeneration is obscure in the first place. Why is that so unthinkably far out but e.g. self-driving cars are taken seriously?
The linked video in the grandparent post argues pretty convincingly that the body might know exactly that, actually.
The key insight seems to be that you can hack the (as the research put it, by analogy) software of a set of cells and let the hardware (DNA, cell mechanisms) worry about exactly how to do what you told them to do, so rather than, say, figuring out how to read DNA and tell what kind of organism will come out of it such that we can start adding or removing bits here and there (very, very hard), you can instead screw around with inter-cell signaling to hijack functionality that the cells already have, but just aren't using, to get them to do new things.
I thought there were several "holy shit" moments in the video. The cancer thing—yikes. Reconnect genetically-broken, actively dangerous cells to the inter-cell communication network and they stop acting crazy, while still having messed-up DNA? That's a surprising result, and a powerful demonstration of what the technique can accomplish (may not be therapeutically useful for a bunch of reasons I can think up, but it still seems like a notable, surprising result)
Another was the sticky "memory" of a modified organism, that is, the worm that'd had its tail cut off then been instructed to make a second head there instead, and then had that cut off and... grew a head again, without further prompting, demonstrating that body layout and gene expression is some combination of DNA and a kind of cell-memory or cell-state across the whole organism, not something driven entirely deterministically by DNA alone.
The part about tricking worms into growing heads for 100-150 million-year separated evolutionary relatives, complete with the correct-for-the-other-species brain, was nuts. The "instructions" are still there, just dormant, and if you confuse the cell-memory (if you will) of what it's supposed to be it'll sometimes decide to be the wrong species. WTF.
Even cooler, perhaps, are eyeless cave fish redeveloping eyes quite quickly after a few generations in the light. It seems like a lot of things are like that. When we look at the fossil record it looks like things evolve in leaps and bounds rather than more gradually over time. Maybe that's because organisms are more built with prefabs rather than from scratch.
Cells think.
There's no a prior reason (I can see) to disallow that humans and other multicellular life forms are the "art" of microbes. (We are Solaris) It seems to me that we are the products of intelligent design, not (necessarily) of the intelligence of God, but of the intelligence of the biosphere itself.
Circumcision, and perhaps female breast cancer, aside: the accumulated evidence is pretty strongly in the opposite direction. There have been quite a few studies on the topic over the last 30 years, with little improvement.
For instance, my mother is aghast at the prospect of clipping a dog's ears or docking it's tail. And yet, when it came to the birth of her sons the same sense of ethics never registered about circumcision.
Her disturbing response: "But if you let him choose he will say no."
There's plenty of examples where we do what's "best" for kids without their consent. Vaccines for example. So I don't really buy this "their body" argument, although I respect the merits.
> Three randomized clinical trials showed that adult male circumcision significantly reduced the risk for HIV acquisition among heterosexual males by 51%–60% (95% confidence interval 16%–76%) over time. These trials also found that medically performed adult circumcision significantly reduced the risk of men acquiring two common sexually transmitted infections (STIs), including genital ulcer disease (GUD) prevalence by 47% and incidence by 48% and high-risk (i.e. oncogenic) types of human papilloma virus (HR-HPV) prevalence by 23%–47%.
It also seems to reduce the risk of UTIs
> Male circumcision has been shown to reduce the risk of urinary tract infections inmales aged 0–1 years by 90%, in males aged 1–16 years by 85%, and in males >16 years by 71%.
This data is from a report from the CDC https://stacks.cdc.gov/view/cdc/58456
Now, whether these would worth the tradeoff with reduced sensitivity, surgical risks (e.g. reduced sexual function due to tight scar formation), the psychological trauma for the infant, etc. is another question.
Obviously there's some trade off here, and I don't think it's worth it to circumcise anyone without their consent or medical necessity.
That's not a valid reason to have it done.
It's easy to keep yourself clean and I've never once heard of anyone getting sores because they failed to wash for an extended period of time.
And I should add that even if it were shown to be 'cleaner' (as far as the reduction of the chance to contract STD's), I would not find that compelling enough to cut off the most nerve dense part of the penis before the person is able to consent.
"In 2010, the World Health Organization (WHO) estimated 30% of adult males worldwide (aged 15+) are circumcised, with about two-thirds of those being Muslims" - https://en.wikipedia.org/wiki/Prevalence_of_circumcision
While female genital mutilation is far more horrific, male genital mutilation is far more common. Both should be ended and the movements should be combined.
I actually make this my single largest political issue and the fact that most people laugh at this idea is evidence for the shockingly bad ethical systems that most individuals have.
That would completely upend orthodontics too, if there was an option to regrow crooked teeth rather than yanking them into position with wires.
As for crooked teeth, it seems to me that Levin et. al. are unlocking the patterns that govern such things, and we can hopefully look forward to even jaws and even correcting deformed bone structures.
It's interesting to try to think about what form a machine would take for "re-imprinting" new skeletal structures into existing bones, eh?
the grinding/taste/vibration/experience of a filling is much worse for me than the experience of an extraction.
I don't know if that's rare or not -- but I have a very real aversion to the experience of dental grinding equipment, and that stuff tends not to get used much if at all during extractions.
I imagine some kind of gel that would react with the cavity to build some indestructible filling without any mecanical intervention.
Ironic, given that this is Hacker News and full of talk of “disruption”.
I have no clue how it was enforced, but the best guess I have for the reason is that it was to protect broadcasters and electric power distribution system operators against liability for any such effects they caused that might go wrong.
Part of debugging is turning off something for a short time, moderns have a tendency to assume everything in the past was done out of ignorance and debugging isn’t required, destruction is.