Limits of Genetic Engineering?

[Covenant]

I've wondered for a while, what's the conceivable endpoint that meat gives us? If you were to make your best effort to find the extremes of what can be done with genetic engineering, with the only real limitation that the result needs to be a breedable person (of some deformed variety), and not some sort of brainles chimera, what could you do with it?

It's easy to think up basic things like endurance, strength, immunity to certain toxins, longevity and so on. But I'm not sure that firing lightning out of your hands would ever be feasible, no matter how BioShock makes it seem, and there have to be several other limitations.

Assume that magical mindpowers don't exist--no bizzare hidden "Psyker Gene" hidden in the code that we just haven't unlocked. There's really no evidence for that, so no reason to include it.

[Cykeisme]

I would figure something more or less in line with the Emperor's finest, the Adeptus Astartes.

[The Grim Squeaker]

Well, some very funky shit opens up if you specialize and don't care about caloric intake, something that needs 10k calories a day and is built for something specific would be light-years ahead of an unspecialized lump carrying excess baggage, extra teeth and organs and that subsists on 1-3K calories a day. (Look at what a Cheetah can do, and it still manages to run in "the black" in terms of food, fat).

Astartes is pushing it, but something like the low-end Nids without the acid spitting or near mono-molecular claws might be possible in limited ways (If you have a support structure, if you have a caloric limit then less funky stuff would be available, although hardware add-ons could help with, say, heating),

[dragon]

It would be possible to adapt people to enviroments not normally suited for them. Wonder if we could adapt people to live on mars with little or normal life support.

[Cykeisme]

It would be possible to adapt people to enviroments not normally suited for them. Wonder if we could adapt people to live on mars with little or normal life support.

Hmm.. what sort of adaptations would we need to allow a mod-person to live with oxygen concentrations as low as Mars' atmosphere? They'd have to be really lethargic or something.

I'm not sure if there's enough oxygen to keep the metabolism going at high enough a rate to maintain an internal temperature at which basic life processes (enzymes and such?) can function.
Unless we changed even that.. but at some point they stop being "people" per se.

[Covenant]

I'm considering mostly that peopleness is in the mind. Though it might drive people insane to be GE'd into dolphins with the minds of a terrestrial primate, you'd still have a 'person' in there somewhere. Reproduction is one of the key limiting factors, as well as that, since if your new Ubermen aren't able to make kids, they're little more than lab-built chimeras.

For those purposes, if you just want to construct super-soldiers, you can get into cyborging (or just put them in a battletank) and do it better, faster, quicker.

The advantage of GE widespread is that it becomes a 'free' advantage. If everyone gets the Adeptus Genemod that turns them into fearless 10 foot hulking death-machines, but doesn't restrict their ability to breed or socialize, then you've effectively upgraded your entire species. If you did the same sort of thing but removed most diseases, unnecessary organs, the obesity genes and turned off bone loss, you end up with a much healthier people. If nobody ever got sick again, that'd be beneficial, and certainly 'cheaper' in the longterm than healthcare.

There's always an ethical question as the result, but I was mostly interested in what you could do. The Space Marines, for example, could they be better done with robots or cyborging? Outside of that theme, would it even be beneficial to replicate the Hulk in a military uniform? Or does it just mean your soldiers are going to be catching a lot more bullets?

[Admiral Valdemar]

I've wondered for a while, what's the conceivable endpoint that meat gives us? If you were to make your best effort to find the extremes of what can be done with genetic engineering, with the only real limitation that the result needs to be a breedable person (of some deformed variety), and not some sort of brainles chimera, what could you do with it?

It's easy to think up basic things like endurance, strength, immunity to certain toxins, longevity and so on. But I'm not sure that firing lightning out of your hands would ever be feasible, no matter how BioShock makes it seem, and there have to be several other limitations.

Assume that magical mindpowers don't exist--no bizzare hidden "Psyker Gene" hidden in the code that we just haven't unlocked. There's really no evidence for that, so no reason to include it.

The limits are there for you to see everyday in nature. No thunderbolts or instant regeneration of lost limbs, but what could be refined and implemented into humans would make what we have today look pathetic. Genetics isn't all that easy to unravel though, so it's not like pick 'n' mix what you want from other animals and hoping for the best. A lot of what limits us is bio-mechanics, such as our rather dodgy knees and certain joints, or simple set-up of the organ like the reversed eye circuitry.

Though from what I've heard of Bioshock, they did at least choose a mechanism for upgrades that does exist, since bacteria essentially "upgrade" themselves by picking up plasmids that confer resistance to certain compounds for instance.

[Covenant]

Yeah, the verbage is good, it's still a video game though so you need a cooler genetically engineered power than "I can make my skin prick up" or the ability to fire skunk glands out of your wrists.

This subject was of interest, as nearly always the terms "genetically engineered", "powersuit" and "super soldier" are used to describe these amazing feats that seem to be just like magic dressed up as science. But unlike magic, they are remote possibilities, so you need to wonder to what degree it'd be possible.

Genetic engineering is one of the few ways to make a soldier useful once he's going up against robots and other automated combatants. There's got to be a physical upper limit though, at which point you really aren't getting a cost-effective use from your soldiers anymore. It's an extremely popular sci-fi convention, along with the idea of 'ascending,' and it mostly seems like just wishful thinking. The Reign of Meat has got to come to an end sometime though.

[Nephtys]

Genetic engineering is rubbish for 'super soldiering'. While Evolution is a process to produce the most highly optimized and fit organism possible, what is the limiting factor is the basis of non-optimized patterns in the ancestry of the organism. With 'engineering', you can create offshoots from this stock line, but it's never going to be really spectacular unless you effectively start from scratch.

Can you think of any way to make a human (assuming you had magical engineering powers) ever be able to fire a bullet from their body? Let's go to the space marine example. Okay. You've got one of those guys, naked. Is he going to do much against some random person, sitting in a jeep with a machine gun a half mile away in a field?

Like it or not, pretty much anything biology can do on the large scale, engineering can do better.

[Covenant]

And therein lies the big question--what's the point of it? We can make giant hulking musclemen, but it seems pretty non-useful, except for wanking in melee scenes where your characters are somehow forced to wrestle with each other, instead of firing at each other from a mile away with lasers.

Things like super-eyeballs would be nice, but intergrated HUD sensors seem better. I like the idea of GE'd supermen with ground-up redesigned anatomy, so that they are essentially machines that grow and reproduce themselves, since your civilization probably has a rather inefficent and self-serving desire to keep needlessly reproducing organic members of their society based on biological imperitive. It almost seems that, eventually, the need to make organic versions of yourself becomes a serious detriment to the efficency of a society, and you'll need to decide between peak efficency and the selfish want to keep people around.

But without extensive and radical modifications, you're gonna end up like the Culture, where the humans are basically just hanging around, and the civilization itself exists for the purposes of the Minds.

[Sikon]

Given arbitrarily advanced genetic engineering, high radiation tolerance could possibly be engineered, if through countering cancer development and other special concerns of radiation exposure to a multicellular organism along with other changes like the analogy of the bacteria which can survive around 100x or more the lethal radiation exposure limit of more ordinary bacteria:

Pinkish in color and giving off the smell of rotten cabbages, the bacteria were originally isolated in the 1950s from tins of meat that had spoiled despite supposedly sterilizing irradiation.

[...]
Reviving the idea that comets seeded planets with the precursors of life, or even life itself, scientists have had fun speculating that only a radiation-tolerant bacterium such as D. radiodurans could survive interstellar journeys. This is the kind of organism that could do something like that," muses Marvin Frazier, director of the Department of Energy’s (DOE) Microbial Genome Program in Germantown, Md., which funded the just-completed effort to sequence all of D. radiodurans’ genes.

In more earthly matters, investigators have crafted an explanation for why the bacterium evolved its immunity to radiation. They propose that it’s the byproduct of skills needed to survive a lack of water. Scientists have also established that the microbe doesn’t simply shield its DNA from the radiation. It instead has an unprecedented ability to repair genetic damage.

[...]
Indeed, D. radiodurans faces quite a challenge when it is hit with millions of rads. Literally shattering the bacterium’s genetic material into hundreds of fragments, the radiation creates complete breaks in the microbe’s double-stranded molecules of DNA.

A double-strand break is the most difficult kind of DNA damage to repair. The well-studied bacterium Escherichia coli, for example, usually can’t survive more than two or three double-strand breaks. Yet within a few hours, D. radiodurans begins to stitch its thoroughly fractured DNA together, and it eventually resurrects a genome free of mutations.

This enviable talent long puzzled researchers. What evolutionary pressure could have forced D. radiodurans to develop such repair skills? There are rare cases in which radioactive elements such as uranium or thorium concentrate underground in large amounts, but the radiation fluxes near those sites are still small compared with what the microbe can withstand. Moreover, D. radiodurans’ oxygen use and other aspects of its metabolism suggest that the bacterium evolved on the surface of the planet, not underground in radiation hot spots.

"There are no natural environments that have fluxes of radiation that could have selected for this organism," says Daly.

A few years ago, Battista’s group tested an alternative hypothesis. Noting that D. radiodurans can also withstand extended periods without water, Robert G. Murray of the University of Western Ontario in London, Ontario, many years ago put forth the theory that its DNA-repair system evolved to combat desiccation. A much more common problem for bacteria, dehydration helps explain the popularity of spores: The capsules hold in the last available drops of water.

Battista and his colleagues found that dehydration does indeed generate the same double-strand breaks in DNA as irradiation does. Moreover, using chemicals that create mutations that the microbe is unable to fix, the scientists produced strains of D. radiodurans that had lost their resistance to radiation. Each mutant strain proved vulnerable to dehydration.

"Our conclusion was that D. radiodurans was an organism built upon the ability to survive prolonged periods of desiccation," says Battista.

The researchers are still struggling to prove that case. They unsuccessfully searched a Chilean desert for the bacterium, for example. Meanwhile, relatives of the microbe have recently been found in areas unlikely to suffer a lack of water, such as hot springs. Since heat induces double-strand DNA breaks, the springs might have also forced the bacteria to develop their survival skills, notes Battista.

[...]
While the evolutionary origin of D. radiodurans’ repair system remains unresolved, so does the system’s secret to success. Daly and Minton have studied two DNA-repair strategies employed by the bacterium.

Initially, it uses a process called single-strand annealing to reconnect some chromosome fragments. Its more crucial method, known as homologous recombination, uses a protein called RecA to patch double-strand breaks. After searching through the multiple copies of the genome that exist in each bacterium, RecA and associated proteins identify an intact copy of a DNA sequence that needs repair and uses that copy to mend and rejoin the broken strand.

Yet neither single-strand annealing nor homologous recombination is unique to D. radiodurans. "Those systems alone can’t account for its radiation resistance," says Daly.

Nor does redundancy in the microbe’s genome explain the phenomenon. Four to 10 copies of the D. radiodurans genome exist in each bacterium. These backup copies are crucial because they increase the odds that a mutated gene will have an undamaged counterpart. Battista’s group has shown that when D. radiodurans grows under conditions that reduce its number of genome copies, the bacterium becomes more vulnerable to radiation. Nevertheless, other bacteria also keep extra copies of their genome.

"The fact that there are multiple copies of the genome is not in and of itself a sufficient explanation for why they’re so radiation resistant. They have to have the capacity to use that redundant genetic information in a way that most organisms cannot," says Battista.

Daly and Minton have proposed that, to speed homologous recombination, the bacterium aligns copies of its genome so that identical DNA sequences are near each other. Since bacterial chromosomes usually come in circles, this theory invokes pictures of stacked loops of DNA, resembling a roll of hard candies, and so has earned the name the Life Saver hypothesis.

[...]
"The problem with all bioremediation organisms, whether they degrade a toxin or immobilize a metal, is that they are sensitive to radiation. In other words, if you’re dealing with radioactive waste, all the standard bioremediation organisms are killed," explains Daly.

D. radiodurans may offer a solution.

[...]
The first fruits of this effort appear in the October Nature Biotechnology, where Daly and Minton, working with Lawrence P. Wackett and Cleston C. Lange of the University of Minnesota in St. Paul, report that the bacterium can grow and partially metabolize toluene or related compounds, even while subjected to constant irradiation of 6,000 rads per hour. Because the microbe doesn’t normally find those organic pollutants tasty, the researchers had to import genes into D. radiodurans from a bacterium already known to degrade such compounds.

The researchers still hope to furnish the radiation-resistant bacteria with the genes needed to break down toluene fully. The carbon and other molecules that result can then generate more energy for microbial growth. The addition of genes required to metabolize other compounds, such as TCE, is also planned.

From here.

On a separate topic, the power of intelligence is not to be underestimated. A tiny fraction of the total genetic code of humans differing from chimpanzees in the right manners led to humans dominating the planet over other species. Human intelligence was obtained by a combination of having several times the brain mass of chimpanzees along with genetics for brain structure making effective use of the neural number increase, plus environmental factors of how children are taught during childhood. Compared to physically stronger animals, brain won over brawn.

The brain size of neanderthals versus homo sapiens was likely not much of an exception to the trend, e.g.:

Neanderthal brains differed from those of H.sapiens in having a much larger occipital region at the back. Since the occipital region of the brain tends to be involved in sensory processing, the 'larger' brains of Neanderthals needn't have made them more intelligent than us sappies - it probably just gave them much keener senses than us.

From here.

There have been challenges in nature: The majority of homo sapiens infant food consumption is required to support the brain's energy usage; the brain size of human infants was able to occur only after pelvic changes allowing birth of babies with such large heads; and there are more complications. Nevertheless, the trend has been towards greater brain size over time. Although brain size is not at all the only factor influencing intelligence, truly vast changes in intelligence have required brain size increase.



Of course, protein-based biology has some limits even with hypothetical advanced genetic engineering. A greater means of potential intelligence increase is the route to cyborgs, artificial intelligence, and nanotech. The theoretical limits of artificial neuron equivalents are far higher, orders of magnitude greater performance per unit volume. It is uncertain which of the biological or non-biological routes will become technologically obtainable first. Possibly, capable non-biological intelligence may be developed before sufficiently advanced genetic engineering anyway.

[Starglider]

And therein lies the big question--what's the point of it? We can make giant hulking musclemen, but it seems pretty non-useful, except for wanking in melee scenes where your characters are somehow forced to wrestle with each other, instead of firing at each other from a mile away with lasers.

But the musclemen can carry bigger lasers.

Things like super-eyeballs would be nice, but intergrated HUD sensors seem better.

In the long run, technology always outperforms biology, because ultimately biology is just machines that you have to build from the inside out using only proteins, low energy reactions, diffusive transport, an unreliable low-density coding mechanism etc etc. Even without the abysmal design ability of evolution (give human designers one billion years to work on the problem and we'd come up with something a hell of a lot better than current mammal biology), in the long run biology amounts to nothing more than a bag of unnecessary limitations.

As you can see, I am already practicing the speech I will give to my robot legions as they march out to conquer the world.

I like the idea of GE'd supermen with ground-up redesigned anatomy, so that they are essentially machines that grow and reproduce themselves,

Machines don't have to be biological to reproduce themselves. Plus for practical purposes why bother with this 'growth' nonsense? That's one of the worst design constraints. We could make new humanoids (if that's what you want) much faster and better if we just assembled them whole from parts.

But without extensive and radical modifications, you're gonna end up like the Culture, where the humans are basically just hanging around, and the civilization itself exists for the purposes of the Minds.

Yep. Actually all those supposedly organic Culture humans are uploads in a shared Mind-run VR simulation. The Minds turned all the physical matter into computronium long ago and just didn't have the heart to tell them.

[Admiral Valdemar]

I see genetic engineering as a stop gap until we have superior cybernetics or can fully become machine based, but still retain our original forms for sentimental sake (just without being kept back by our trusty old natural bodies).

There are plenty of implants we can have today to help aid our bodies, but they don't regenerate when damaged, are highly inefficient for energy usage and often far too bulky and clumsy. Which is why I see current medical challenges being taken care of via GE and ESCs etc. for now.

Make no mistake, if you put a GE soldier up against the equivalent robot, I know who I'd bet on. There's only so much human ingenuity and determination can do against a hardy exoskeleton of steel with a simple track-and-shoot program and gun.

[Starglider]

There's only so much human ingenuity and determination can do against a hardy exoskeleton of steel with a simple track-and-shoot program and gun.

Human ingenuity and dermination are vastly overrated, compared to a brain that runs at 20 GHz instead of 200 Hz, with perfect recall of a vast tactical database, software that can run thousands of probabilistic simulations of every possible near-future scenario at once without getting confused or distracted, and absolutely no concept of 'fear', 'despair' or 'surrender' except as an exploitable psychological weakness in the enemy. Determination is something humans try to use, with very limited success, to overcome our natural weaknesses. Rational AIs will devote their entire minds and beings to achieving their goals, all the time, without ever letting up or taking a break or getting tired or doubting themselves.

[Covenant]

Here's a question then, on the subject of total mechanization: Do you think the mind of an animal like us would be able to exist properly within a body that is completely artificial?

Or would our idiotic impulses, natural responses, and so on inherently hamper us to a degree that makes us far less useful?

I suppose it depends on the likelyness of developing human or human+ AI systems. I'm trying to figure out if there's a way for an Arbitrarily advanced civilization to justify meat-and-bones citizenry, leaders, scientists, and so on--besides vanity. Vanity is the ultime expression of "We're going to stay around, simply because we want to," even if there's no value to it.

It's a thought experiment. Of the far-future civilizations written of, few of them are actually mechanized and intelligent. Most of them end up being some kind of dimwitted computer-mind like HAL linked to a vast swarm of antlike drones.

[Starglider]

Here's a question then, on the subject of total mechanization: Do you think the mind of an animal like us would be able to exist properly within a body that is completely artificial?

Yes.

Or would our idiotic impulses, natural responses, and so on inherently hamper us to a degree that makes us far less useful?

Not any worse than we are now.

I'm trying to figure out if there's a way for an Arbitrarily advanced civilization to justify meat-and-bones citizenry, leaders, scientists, and so on--besides vanity. Vanity is the ultime expression of "We're going to stay around, simply because we want to," even if there's no value to it.

No not really. Even for experiencing what historical humans felt like, with arbitrarily advanced computers you can do it just as well in simulation.

Most of them end up being some kind of dimwitted computer-mind like HAL linked to a vast swarm of antlike drones.

This is why Greg Egan rocks.

[Admiral Valdemar]

Human ingenuity and dermination are vastly overrated, compared to a brain that runs at 20 GHz instead of 200 Hz, with perfect recall of a vast tactical database, software that can run thousands of probabilistic simulations of every possible near-future scenario at once without getting confused or distracted, and absolutely no concept of 'fear', 'despair' or 'surrender' except as an exploitable psychological weakness in the enemy. Determination is something humans try to use, with very limited success, to overcome our natural weaknesses. Rational AIs will devote their entire minds and beings to achieving their goals, all the time, without ever letting up or taking a break or getting tired or doubting themselves.

Hence the "There's only so much human ingenuity and determination can do".

Much as you may pooh-pooh the idea, it's humans that are making machines to improve ourselves, not the other way around. Let me know when a silicon computer spontaneously arises from sludge, rises to conquer a whole planet, then work on tools that will only further enhance an already unstoppable might. Humans are awesome machines. We're just making ourselves more awesome.

[Starglider]

Much as you may pooh-pooh the idea, it's humans that are making machines to improve ourselves, not the other way around.

This is an oxymoron. Of course evolved intelligences have to come first, that's what 'designed artefact' means.

Let me know when a silicon computer spontaneously arises from sludge,

In what way could this possibly be considered an advantage? On the contrary, it is the source of all the horrible short-sighted legacy crap in biological designs. Being evolved from sludge is nothing to be proud of.

Humans are awesome machines.

Only on the scale of what humans themselves have built to date, and even then only on generous holistic metrics.

[Admiral Valdemar]

This is an oxymoron. Of course evolved intelligences have to come first, that's what 'designed artefact' means.

Well duh, my point.

In what way could this possibly be considered an advantage? On the contrary, it is the source of all the horrible short-sighted legacy crap in biological designs. Being evolved from sludge is nothing to be proud of.

It's not an advantage, it's a fact. What argument do you think I'm proposing here? The point is that evolution is an amazing thing to behold and fascinates me much more than any designer example, something Creationists are obviously fond of and feel is more worthy of wonder. Whether it is "superior" or not is totally irrelevant.

Only on the scale of what humans themselves have built to date, and even then only on generous holistic metrics.

And still awesome. Until something we make or find totally trumps us at everything, there has yet to be a complex machine found to rival us and better ourselves. And we did it all on our own, not via some deity or quirk of nature or other designer (that we know of, that'd screw Creationist minds up if the Grays made us one lazy Sunday).

I just wish I could see what we'll become in another millennia or two, when talk about genetic engineering, computing and physics today is no better than the babbling of a toddler in comparison to what we may learn. I'd freeze myself, but I don't have Walt Disney's fortune, annoyingly.

[Sikon]

Here's a question then, on the subject of total mechanization: Do you think the mind of an animal like us would be able to exist properly within a body that is completely artificial?

Given sufficiently advanced technology, if making the artificial body fully resemble a biological body was the goal, perfectly reproducing appearance and all senses, a human mind literally could not tell the difference for practical purposes ... aside from whatever improvements were deemed desirable. For example, someone may want built-in radio telepathy, but, if they're a human mind, they may still want the same sense of touch, feeling, taste, smell, etc. Advanced technology means far more than just rigid metal being available as an option. Today's biological cells are simply a limited subset of all possible machines given sufficient technology.

Or would our idiotic impulses, natural responses, and so on inherently hamper us to a degree that makes us far less useful?

I suppose it depends on the likelyness of developing human or human+ AI systems. I'm trying to figure out if there's a way for an Arbitrarily advanced civilization to justify meat-and-bones citizenry, leaders, scientists, and so on--besides vanity. Vanity is the ultime expression of "We're going to stay around, simply because we want to," even if there's no value to it.

It's a thought experiment. Of the far-future civilizations written of, few of them are actually mechanized and intelligent. Most of them end up being some kind of dimwitted computer-mind like HAL linked to a vast swarm of antlike drones.

A civilization with sufficiently advanced technology would have the capability for its people (sapients) to have any of various types of avatars. Given sufficient technology, good telepresence is indistinguishable from inhabiting a body (outside of unnecessarily attempting such at a distance so extreme as to have significant lightspeed lag). With that kind of technology, avatar bodies with appearance indistinguishable from biological human bodies are entirely an option.

Of course, that doesn't mean such would necessarily be chosen. But, for example, if everybody's a giant metal spider all the time and never even temporarily takes humanoid form, such would be so only because that body form was actually preferred.

If a society includes minds which were once human before being upgraded, they might retain some human aesthetic preferences, in which case they might prefer to have humanoid avatars, at least part of the time.

(There is the virtual world possibility where all recreation, etc. takes place in a perfect simulation rather than the real world, but such likely wouldn't be preferred unless it was indistinguishable from physical reality, in which case it is the same in regard to potential enjoyment).

Even if not upgraded cyborged humans, possibly the first sapient AIs might have a preference for humanoid form.

An adult human brain has roughly on the order of 1E15 bit complexity in its "programming" ... million gigabit level. But that is after the factor of million increase through learning that happens in the human brain over time between conception and later childhood, particularly before several years of age.

A person's brain starts with whatever fraction of no more than merely 3 gigabytes of total DNA (3E9 base pairs) is devoted to brain structure information. Then the baby learns from childhood interaction with the environment, including socializing with other people, reaching on the order of 1E15 bytes of stored data complexity.

In contrast, a lot of sci-fi depicts the first sapient AI as more or less the equivalent of a brain in a box: a computer without any avatar body, imagined to have sapience just through pre-programming rather than gradually obtaining such through learning. Without interaction with the environment prior to full-fledged sapience and without gradual learning like that of a human baby and child, such implicitly is assuming human programmers somehow manage to encode "from scratch" the equivalent of the ~ 1E15 bit complexity of a sapient human brain.

However, a far more plausible technique would be just to program vastly less, like some gigabytes of seed code, while having the first sapient AI have the complexity of its "programming" subsequently increase by orders of magnitude and become sapient through having an avatar body which interacts with the environment and learns over time. Reproduce the equivalent of the factor of a million increase in encoded data that happens between the genetic material at conception for a human versus the adult human brain.

(Possibly, there might be additional similarities to biological brain development for the first sapient AI if its seed code was developed by understanding and partially copying that of progressively more complex biological organisms, from those with simple nervous systems to those with complex brains ... insect-level before lizard-level before human-level ... though it remains to be seen whether that occurs or whether other computer programming techniques actually succeed).

There are multiple possibilities for what form the first sapient AI's avatar could take. However, it would be rather convenient for it to have hands, for learning by manipulating objects in the real world, and feet are more flexible for going about indoors than wheels alone. Possibly it might be humanoid form.

So the first sapient AI could very possibly start with having learned to live in humanoid form, potentially working best with such.

Of course, after that, things get more complicated, as potentially sapient AIs may become more and more alien. If viewed acceptable and if desired, subsequent AIs might not need to reproduce the time-consuming process of learning, as the whole contents of the first "adult" AI mind might be simply copied to new AIs. That's when "brain in a box" type sapient AI computers without physical avatar bodies are technically possible ... although there still obviously can be advantages in having physical avatars to interact with the real world. At this point, if the AIs become recursively self-improving, if they modify the "programming" of their brains, it's hard to say what would become the desired form of the equipment used by them to interact with the environment. Perhaps none of it would resemble humanoid bodies at all, maybe.

However, from the preceding, it can be seen that there's significant potential for humanoid bodies being used sometimes by more than non-upgraded biological humans alone.

[Starglider]

The point is that evolution is an amazing thing to behold

In the 'amazing that it works at all' sense, yes. Of course it requires a billion years, an entire planet and a huge amount of luck (in both the initial conditions and the later events) to produce humans. My point is that given those kind of resources, humans could do much, much better, to say nothing of transhuman intelligences. Furthermore natural selection is quite literally fueled by pain and death and suffering on a scale many orders of magnitude beyond the human mind's ability to grasp. This is why biology and the earth's evolutionary history is an argument against rather than for the existence of an intelligent creator; it's full of mistakes and hacks, it shows no design foresight whatsoever, it's monstrously slow and inefficient, and it's incredibly immoral.

And we did it all on our own, not via some deity or quirk of nature or other designer (that we know of, that'd screw Creationist minds up if the Grays made us one lazy Sunday).

Well yes, which is an accomplishment (and yes pissing off fundies who believe 'man should not play god' is a minor bonus).

I'd freeze myself, but I don't have Walt Disney's fortune, annoyingly.

It's fairly cost effective these days actually, a moderate life insurance policy will cover it.

[Lord of the Abyss]

Human ingenuity and dermination are vastly overrated, compared to a brain that runs at 20 GHz instead of 200 Hz, with perfect recall of a vast tactical database, software that can run thousands of probabilistic simulations of every possible near-future scenario at once without getting confused or distracted, and absolutely no concept of 'fear', 'despair' or 'surrender' except as an exploitable psychological weakness in the enemy. Determination is something humans try to use, with very limited success, to overcome our natural weaknesses. Rational AIs will devote their entire minds and beings to achieving their goals, all the time, without ever letting up or taking a break or getting tired or doubting themselves.

I'm not at all sure if that's such a good idea, either for us or some future AI civilization. That's essentially creating an army of perfectly fanatic soldiers, and that strikes me as a bad idea. AI or human, I'd think you'd want an army composed of beings that have the occasional feeling of fear or doubt or self questioning ( or the AI equivalent ). Otherwise, you risk either handing a tyranny the perfect tool of oppression and conquest, or having the army run wild in a Frankenstein situation.

Anything that is that focused on the goal and only the goal, you want to be stupid, at least compared to you. That way if it's rigidity leads it into behaving dangerously, you can disable or destroy it. You don't want something smart and rigid at the same time. If your AIs made an army like that, the wrong order or programming error could find them killed off and supplanted by their own military machine.

And the same applies to non-military matters as well. While an AI that "will devote their entire minds and beings to achieving their goals, all the time, without ever letting up or taking a break or getting tired or doubting themselves" might make a better specialist than any human, it could be very dangerous to anyone or anything that got in the way of whatever goal it's pursuing. Including other AIs. A wise AI civilization will want it's component AIs to be good AI citizens or equivalent, even if it makes them somewhat less efficient in a purely performance sense.

[Admiral Valdemar]

In the 'amazing that it works at all' sense, yes. Of course it requires a billion years, an entire planet and a huge amount of luck (in both the initial conditions and the later events) to produce humans. My point is that given those kind of resources, humans could do much, much better, to say nothing of transhuman intelligences. Furthermore natural selection is quite literally fueled by pain and death and suffering on a scale many orders of magnitude beyond the human mind's ability to grasp. This is why biology and the earth's evolutionary history is an argument against rather than for the existence of an intelligent creator; it's full of mistakes and hacks, it shows no design foresight whatsoever, it's monstrously slow and inefficient, and it's incredibly immoral.

It's too bad the fundies don't take this on-board as a good testament against their "benevolent" deity. We didn't have any higher power guide us, more like the fundamental forces of physics. Blood, sweat and iron got us where we are now, not Biblical teachings or kindred spirits. Sometimes the human manufactured universe is just less interesting and fascinating. How dull would science lessons be if "Goddidit" was the answer?

Well yes, which is an accomplishment (and yes pissing off fundies who believe 'man should not play god' is a minor bonus).

The number of things we could stamp with "playing god" is hilariously large. They, funnily, only pull that out when scientists go and use something terrifying like transgenic mice. Oh no! Mice with human heads, what possible use is that? Oh wait, it's not a comic book and the whole thing saves lives. Like animal rights activists and neo-con senators, they're huge hypocrites

It's fairly cost effective these days actually, a moderate life insurance policy will cover it.

For your head, at least. I believe Walt Disney didn't pay for his whole body, but that may be down to the cyronics not being as advanced when he left this mortal coil.

Personally, I'd rather upload myself into a sufficiently advanced computer and screw virtual catgirls until I can tailor make my own body again.

[Lord of the Abyss]

For your head, at least. I believe Walt Disney didn't pay for his whole body, but that may be down to the cyronics not being as advanced when he left this mortal coil.

Actually, he was cremated, and the cryonic Disney bit is a myth. Some details in this Straight Dope column.

[Zixinus]

Getting back to topic:

We are talking about how far can human biology be pushed. How far do you want to go and what do you want to go?

Higher resistance to radiation and no bone loss genes would be very useful for space marines, but not for Inuit Homer, who is working his ass off all day to get every bit of calorie he can get, doesn't hibernate and has radiation dosage that are negligible. But Inuit Homer may suffer from the side-effects or risks of these genes without enjoying the benefits.
However, genes that take up fat rather then muscle, and form fat cells in a fashion that further shields him from the bitchin' cold, are appreciated.

So, its a bit like a trading game. If you put this tendency in, it will have side effects. A trait can be crippling in one environment, but can be enormously useful in another.

There are plenty of things that could be done with genetic engineering.

In my fictional setting, it is used, among many others, for people to rapidly adopt to a planet that humans could not natively habit otherwise. Not only people, but animals and plants (plants first of course). The thing is not done by the colonists, but by a group of super-geniuses with highly advanced technology (that they do not share with the colonists).
With this, rapid progression may come to the point that new organs and features develop under generations, rather then millenas.

As Sikon mentioned, size does matter with the brain. People could learn faster and better, understand and deduce faster. Admirals with instinct understanding of any strategic and tactical knowledge, soldiers that rapidly experiment and learn from local environment, etc.

In my setting, one particular aspect is manipulated, one that was a trait in a legendary fighter: it's called " Warrior's Haze". Essentially a trigger that causes to nervous system to become hyperactive along with rapid and even dangerous shots of adrenaline and other chemicals. What is special, is that the owners of these genes can trigger this consciously and on demand. As time and research goes on, other effects are also discovered, one that calms down movement, one that can cause coma-like state on demand, etc.
Of course, their body can take so much of it, especially their nervous system. Many are forced to use prosthetics to overcome the damage done. But this makes them incredible fighters that are to be feared whether they have lasers or swords.