I think the big factor there is that you'd have to wait over a decade for the transplant to be the correct size. I'm also not sure that we have the technology to keep a brainless body alive for such a long period - the brain is involved in a large number of processes that we don't yet have a way to replicate. And then you'd need a complex surgery to perform the transplant.

Pluripotent cells work fine in many animals with no apparent problems and avoid all of the issues with the clone approach. If pluripotent cells turn out to cause problems, then we could always engineer a kill switch to make sure they die off after the limb is regrown.

Gets you a factor of two if you're lucky. Imagine the mental fidelity of presidents 46 and 47 when they're ready for a third full body transplant.

What if we transplant just part of the brain?

Brain is necessary for growth , repair , and several immune responses. Do you want a zombie arm?

ya, but no be riding the glitch train I have a atrong sense that the brain is very much involved in growing the rest of the nervous system......which the "parts" need to function these hypothetical procedures will be hugely complex surgeries that will take a long, realy long time, and there will be complications, so the risk to benifit ratio will only be good in a few scenarios....for which you need a wildly complex and expensive facility to prepare for many years in advance. gets worse, as the timing of procedures may require "parts" that are critical for the....."chasis" to self maintain, then requiring other back up "chasis" gets even worse, as the learning curve is going to be exceptionaly steep, and long, almost certainly meaning that who ever trys first, wont live long enough to benifit. all for what? a new chasis for a worn out brain?

> "It's our minds that are special. We should be able to transplant every other part."

The gut has the enteric nervous system with half a billion nerve cells and a hundred million neurons. Where's the clear divide between 'brain' and 'everything else'?

> "full head transplants could tackle every disease except"

except being quadraplegic and in an Iron Lung because reconnecting the spinal column is indistinguishable from magic at this point. What about the risks involved in major surgery and rehab? The hospital staffing and effort and costs involved in doing multiple organ transplant surgeries per lifetime for each of hundreds of millions of people? Saying "it's so simple" doesn't make it simple.

It turns out that you can induce pluripotency with all four Yamanaka factors, but there's a significant risk of the pluripotent cells turning into cancer.

But by using only three of the four factors, you can still induce pluripotency, but with much lower cancer risk.

I think that cloning individual organs is much more promising than cloning entire bodies and then harvesting. Much less work, you don't have an entire body you need to either upkeep or dispose of.

From what I’ve read, Salamanders of all kind retain their stem-cell embryonic growth capabilities in their early life (after birth). But once they become adults, they become more mortal like the rest of us. But Axolotls for some reason never lose their ability.

Isn’t the whole body growing from the same point at the same pace in a lot of instances when someone is in the womb (except when something like thalidomide is introduced)? It would seem a big challenge would be to have a part of a human body, at any number of stages after birth, maybe especially after full development, regrow from nothing, and excluding, at the very least, the areas of the body in proximity to it.

I’m obviously not an expert.

Interesting. Did nerves grow back too?

I think people often hear 'bioelectric' and think it means electricity (electron flux) but what Levin's work is about is a pattern of voltage gradients (that cells maintain using electrically-non-neutral chemicals) that stores a pattern like a memory (or "target in morphospace" as Levin would say) of what to grow back into when the tissue is damaged.

It is about ion transfer between cells that sets up and maintains those patterns of electrochemical gradients. Gap junctions (the cellular pores that facilitate ion transfer) are not unique to neuron cells either, and nor are they even unique to multicellular tissues! It is now thought that this type of intercellular communication evolved in single-celled microorganisms even before the advent of multicellularity (like in biofilms and in quorum-sensing such as what yeasts are known to employ).

I totally see what you're saying if you interpret this as electricity like electrons/electromagnetic-fields in a wire with power running through it, but that is really not what Levin's work is about at all.

> You can vary the voltage (a bit) and polarity. Maybe the steepness of the voltage gradient.

But that's literally all that you need, isn't it? I understood the whole thing about Levin's bio-electric fields is this: it's a "global" signal that lets cells know where they are in the target structure that's not uniformly symmetric. It's not the full structure description, just lowest-frequency view - head is here, tail is there, etc.

Also I thought that was experimentally confirmed.

maybe the electricity is not the encoding, it's a trigger for some surface gap junctions to alter internal state / logic

> if you would eat for some days chicken livers as your only source of proteins

How many days? Because when we cook chicken livers we make enough for like 3 days here... perhaps I'm dead and I don't know it.

> chicken livers are usually cheaper per amount of protein than most other kinds of meat

Any idea why? My layman guess is it’s a non-famous byproduct of chicken muscle, that people tends to consume more. Would removing the availability/demand (=make it more popular) reverse the price?

Thanks for the information about carotene > vitA, it resonates like the heme/non heme iron where the heme one is easier to get but can slip to too much, leading to more oxidation and then (in extreme case) concert (IIRC that’s one of the way too much read meat induce cancer risks). OTOH non heme iron (in cereals, peas, fruits, vegetables and milk) is directly used for catalysis and isn’t store, so one can’t get too much.

I’m a layman, don’t take what I said as authoritative. You’re welcome to point out if I’m wrong or add precision.