[ExI] Homo radiodurans (was Maximum Jailbreak)
William Flynn Wallace
foozler83 at gmail.com
Fri Oct 26 18:43:15 UTC 2018
I don't doubt all that is possible with genetic engineering but it wouldn't
> be easy, I expect by the time it could be done superhuman AI will be around
> so Homo radiodurans will have serious competition. It will be a match
> between biology and electronics and I think electronics will win.
> John K Clark
> Will win what ? No question that AIs will be more adapted to living in
> space and going to Neptune, etc. Getting data from them will be awesome,
> but people want things first-hand. I had an uncle who was fairly widely
> traveled, and his idea of a travel photo was one in which he was in it.
> The other things you could see in a book.
> On Thu, Oct 25, 2018 at 11:45 PM Stuart LaForge <avant at sollegro.com>
>> John Clark wrote:
>> >>> My question about living in space: what do you do about the
>> >>> radiation for the long term?
>> >> Simple, you genetically engineer your space humans to be black. Not
>> >> African black and not just the skin, but pitch-black and including the
>> >> internal organs.
>> > That would give you some protection against ultraviolet light and maybe
>> > even a little against soft X rays but no protection at all against the
>> > most dangerous and hard to shield against type of radiation which isn't
>> > electromagnetic at all, its high speed particles in the form of Cosmic
>> > Rays.
>> Yes. You are right and I am guilty of not properly explaining an idea that
>> I have been kicking around for some time. That being how to best engineer
>> and adapt humans to living in space for the long term. I imagined an
>> offshoot of Homo sapiens called Homo radiodurans that would essentially be
>> humans that had been genetically engineered to better survive the rigors
>> of space travel and long term habitation.
>> I named them for their resistance to radiation but I have imagined other
>> adaptations as well. For example, they would be small by terrestrial
>> standards perhaps 4 feet tall or so. Size is not an asset for people who
>> live in cans. I also envision them being able to enter cryptobiotic
>> suspension for long journeys and such.
>> Homo radiodurans would owe its radiation resistance to being engineeered
>> with specific genes from several known examples of extremophiles that can
>> withstand several orders of magnitude more radiation than would be lethal
>> for a human.
>> You already know about the black melanin producing radiotrophic fungi that
>> photosynthesize using x-rays and gamma rays and we might be be able to get
>> away with simply over-expressing our own melanin genes. But you are right
>> that such would be no defense for cosmic rays of the particulate variety.
>> Therefore I have turned to other extremophiles such as tardigrades or
>> "water bears" and the bacterium Deinococcus radiodurans, which inspired
>> the name of these engineered humans, for solutions. Tardigrades are
>> notable for having survived being directly exposed to the hard vacuum and
>> radiation of space for several hours, so they would be the gold standard
>> for what we could accomplish given the will to engineer our germline.
>> Particulate radiation like high energy protons damage DNA by causing
>> double stranded breaks and knocking electrons about generating reactive
>> free radicals.
>> Organisms that are highly resistant to radiation generally utilize a
>> strategy of gene redundancy and extremely efficient DNA repair and free
>> radical quenching. In other words, they have multiple copies of their
>> chromosomes and several copies of every gene that encodes for DNA repair
>> enzymes and antioxidant enzymes.
>> Humans have DNA repair enzymes as well, but they are not as efficient or
>> numerous as those of tardigrades. For example, humans have about 10
>> varieties of superoxide dismutase (SOD) and enzyme that deactivates oxygen
>> free radicals while tardigrades have 16.
>> Tardigrades also have some unique DNA repair enzymes as well. One of which
>> was actually already introduced into human cell lines a couple of years
>> ago as reported in nature.
>> The upshot of the experiment is that the transfected gene protected the
>> human cells from radiation that killed off the control cells. This is
>> proof of principle that Homo radiodurans is at least theoretically
>> Other strategies would involve conditioning astronauts with gradually
>> increasing dosages of radiation prior to sending them into space. There is
>> some evidence that people can adapt to radiation in this fashion. The
>> phenomenon is called radiation hormesis.
>> However all these biological adaptations and strategies need to be used in
>> conjunction with hardware like adequate shielding of spacecraft and
>> habitations. At the end of the day, no matter what genes you have, a
>> proton with the kinetic energy of major league fastball pitch is going to
>> do some damage to your cells.
>> Space is the most hostile environment we have ever faced. For that reason
>> alone we must conquer it if for no other reason than to test ourselves
>> against eternity.
>> Stuart LaForge
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