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So, radiation is a big risk factor in sending astronauts to Mars and around the solar system. What if we could genetically engineer ourselves to use this melan

So, radiation is a big risk factor in sending astronauts to Mars and around the solar system. What if we could genetically engineer ourselves to use this melanin pathway for ourselves? We wouldn't use energy from radiation in the fungi-melanin pathway (although we could), but it could be good to make our bodies recognize that a radiation storm is happening and that could trigger biochemical changes in our bodies. Either to become more radiation proof (hide yo' DNA in chromatin) or take some radiation-resilient actions (heavily increase the reproduction of cells in our gut lining). This isn't a very realistic idea, just a sci-fi thing. We have a hundred years of ethics and technology to accomplish before this would be realistic.

enraged_camel 13y ago
>>So, radiation is a big risk factor in sending astronauts to Mars and around the solar system. >>What if we could genetically engineer ourselves to use this melanin pathway for ourselves? I had a friend in high school who was really good at biology and wanted to pursue a career in genetics. I asked him why and he said he wanted to design humans that have tiger claws. I think his dream is more realistic than what you suggest. :)
- Houshalter 13y ago
  We already have melanin in our skin to block radiation though, don't we?
  - waps 13y ago
    We have melanin in our skin to block radiation from the sun. Now there's a difference. The sun is emitting thermal radiation of about a million degrees celcius. The energy profile of it's radiation is very well studied. It's basically random radiation with every individual photon being in a defined (and quite low) energy interval. Radiation in space is totally random over the entire spectrum. There aren't many events at all (compared to the sun's radiation you could be forgiven for claiming there isn't any radiation in space at all, so few photons), but the events that do happen have a totally random energy distribution. Meaning most of the rays have enough energy to knock 2 or 3 molecules from the front of your finger into your brain. Or (a very tiny) part of the casing of the ship into deep into your body. If you measure space radiation with your sensor pointed down towards this massive rock we're living on, using the entire mass of the planet to block the radiation, the meter does not go down to zero (even when you eliminate the radiation produced by the planet itself). Metals have a bit of an advantage blocking radiation because they have collective electron orbitals. If radiation impacts an electron inside a metal structure, it's going to throw it centimeters, meters away, maybe even kilometers. But here's the difference : that energy can be dissipated all around the structure. In other words, just because an electron gets an energy boost and gets thrown all around the room does not mean it has left it's orbital at all, and so it should remain inside the metal plate. If it does, the radiation is blocked. It's a sort of "structural integrity" field : the energy delivered does not have to beat the magnetic field of a single atom, but the magnetic field of the entire lattice. Unfortunately, on a per-atom basis, metal magnetic fields are on the very low side (mostly). Ideally you'd use compressed plasma clouds to block radiation. But the energy required for maintaining that is rather enormous. But it would block pretty much all radiation (this is the reason the early universe, despite producing more photons in essentially empty space than the fusion reaction in the sun does today, was "completely dark". Those photons couldn't travel, so they'd never hit any sensor) This is the problem with space radiation. Once radiation energy levels go above certain "reasonable" energy levels blocking it becomes a pipe dream.
    - TheEzEzz 13y ago
      "If you measure space radiation with your sensor pointed down towards this massive rock we're living on, using the entire mass of the planet to block the radiation, the meter does not go down to zero (even when you eliminate the radiation produced by the planet itself)." Can you explain this further? Wouldn't it suggest that we're exposed to the same radiation while on Earth?
      - waps 13y ago
        It's not that the atmosphere does not protect us. Just not 100%, which shows just how much energy (a tiny fraction of) these particles have. So yes, you get a few atoms in your body blown off by a cosmic ray once every few months or so. In space you can expect that to increase to several times per second (as compared to solar rays, which of course constantly hit). This was a statement meant to illustrate that so far we haven't really found an upper bound for the energy levels of these particles. Give a particle enough energy and it'll fly right through the planet. http://en.wikipedia.org/wiki/Cosmic_ray http://en.wikipedia.org/wiki/Cosmic_ray The interesting thing is that we don't actually know where most of these rays come from (about 1 in 100 million comes from a supernova/black hole/other known powerful event). So something is pretty much everywhere in space, shoots out particles like a particle accelerator, except much more powerful than the ones we can build. Yet whatever is doing this manages to avoid detection by any other means.
jlgreco 13y ago
From what I understand of this, the fungus basically "eats" radiation in the sense that plants eat sunlight, but that only prevents the radiation from damaging the fungus to the extent that the radiation hits the melanin instead of hitting the DNA or whatever. So if you made a human that did this, you would have a human that could refrain from eating much food for energy and instead choose to hang out in a nuclear reactor (they would still need to eat to take in nutrients, but would need fewer calories I guess?) ...but they'd also still get radiation poisoning / cancer / etc. Also, it isn't clear to me how these could be used to "clean up" messes anymore than sunbathers could clean up the sun. It seems they just absorb gamma rays, but nothing about them doing that should make that material decay faster... Maybe the idea is that they intake the radioactive particles and consolidate them so that cleanup then entails finding the fungus (which is presumably easier to visually locate) and scooping it all up? Maybe you could engineer the fungus to also bioluminescence strongly to aid in this.
- fragsworth 13y ago
  Likelihood of cancer may be related to the general chance of reproductive mutation, and the chance of reproductive mutation is also likely to be something that changes through evolution. If you have a species in a high-radiation environment, is it not possible that it evolves to have fewer reproductive mutations in general - and therefore lower chance of cancer?
  - jlgreco 13y ago
    Yes, I think it makes sense that certain arrangements of DNA would be less susceptible to going cancerous than others. In one strand you might have a possible '1 bit flip' (I'm not a biologist in the slightest) change that would turn the routine into "while(1) {fork();}", but perhaps in another functionally equivalent strand you would need to flip 2 or 3 bits to get the same effect. So basically you want to select for DNA that has a large (DNA equivalent of) Levenshtein distance to cancerous DNA. Perhaps that is something that you could even deliberately engineer (though I don't think a general solution is possible since determining if DNA is cancerous might be the halting problem?) Maybe it would be easier to construct a strand of DNA that has the same effect as another strand of DNA, but with more error-checking. Throw in a bunch of asserts or something to send cells with DNA that fails the error checking into suicide mode...
hcarvalhoalves 13y ago
> What if we could genetically engineer ourselves to use this melanin pathway for ourselves? I can see this being totally feasible, more than the other approach, which would be to engineer ourselves to fix our own DNA: http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/6607 http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/dis...
hammock 13y ago
You might be surprised. Genetic engineering of our bodies is not necessary to take advantage of melanin's UV absorbent, antioxidant and radical scavenging properties. There have been a couple of "melanin" pills developed to that end. Of course they don't create energy for the body, though. They have also found it difficult to achieve final regulatory approval. http://en.wikipedia.org/wiki/Afamelanotide http://en.wikipedia.org/wiki/Afamelanotide http://en.wikipedia.org/wiki/Melanotan_II http://en.wikipedia.org/wiki/Melanotan_II

enraged_camel 13y ago

>>So, radiation is a big risk factor in sending astronauts to Mars and around the solar system. >>What if we could genetically engineer ourselves to use this melanin pathway for ourselves? I had a friend in high school who was really good at biology and wanted to pursue a career in genetics. I asked him why and he said he wanted to design humans that have tiger claws. I think his dream is more realistic than what you suggest. :)

Houshalter 13y ago
We already have melanin in our skin to block radiation though, don't we?
- waps 13y ago
  We have melanin in our skin to block radiation from the sun. Now there's a difference. The sun is emitting thermal radiation of about a million degrees celcius. The energy profile of it's radiation is very well studied. It's basically random radiation with every individual photon being in a defined (and quite low) energy interval. Radiation in space is totally random over the entire spectrum. There aren't many events at all (compared to the sun's radiation you could be forgiven for claiming there isn't any radiation in space at all, so few photons), but the events that do happen have a totally random energy distribution. Meaning most of the rays have enough energy to knock 2 or 3 molecules from the front of your finger into your brain. Or (a very tiny) part of the casing of the ship into deep into your body. If you measure space radiation with your sensor pointed down towards this massive rock we're living on, using the entire mass of the planet to block the radiation, the meter does not go down to zero (even when you eliminate the radiation produced by the planet itself). Metals have a bit of an advantage blocking radiation because they have collective electron orbitals. If radiation impacts an electron inside a metal structure, it's going to throw it centimeters, meters away, maybe even kilometers. But here's the difference : that energy can be dissipated all around the structure. In other words, just because an electron gets an energy boost and gets thrown all around the room does not mean it has left it's orbital at all, and so it should remain inside the metal plate. If it does, the radiation is blocked. It's a sort of "structural integrity" field : the energy delivered does not have to beat the magnetic field of a single atom, but the magnetic field of the entire lattice. Unfortunately, on a per-atom basis, metal magnetic fields are on the very low side (mostly). Ideally you'd use compressed plasma clouds to block radiation. But the energy required for maintaining that is rather enormous. But it would block pretty much all radiation (this is the reason the early universe, despite producing more photons in essentially empty space than the fusion reaction in the sun does today, was "completely dark". Those photons couldn't travel, so they'd never hit any sensor) This is the problem with space radiation. Once radiation energy levels go above certain "reasonable" energy levels blocking it becomes a pipe dream.
  - TheEzEzz 13y ago
    "If you measure space radiation with your sensor pointed down towards this massive rock we're living on, using the entire mass of the planet to block the radiation, the meter does not go down to zero (even when you eliminate the radiation produced by the planet itself)." Can you explain this further? Wouldn't it suggest that we're exposed to the same radiation while on Earth?
    - waps 13y ago
      It's not that the atmosphere does not protect us. Just not 100%, which shows just how much energy (a tiny fraction of) these particles have. So yes, you get a few atoms in your body blown off by a cosmic ray once every few months or so. In space you can expect that to increase to several times per second (as compared to solar rays, which of course constantly hit). This was a statement meant to illustrate that so far we haven't really found an upper bound for the energy levels of these particles. Give a particle enough energy and it'll fly right through the planet. http://en.wikipedia.org/wiki/Cosmic_ray http://en.wikipedia.org/wiki/Cosmic_ray The interesting thing is that we don't actually know where most of these rays come from (about 1 in 100 million comes from a supernova/black hole/other known powerful event). So something is pretty much everywhere in space, shoots out particles like a particle accelerator, except much more powerful than the ones we can build. Yet whatever is doing this manages to avoid detection by any other means.

jlgreco 13y ago

From what I understand of this, the fungus basically "eats" radiation in the sense that plants eat sunlight, but that only prevents the radiation from damaging the fungus to the extent that the radiation hits the melanin instead of hitting the DNA or whatever. So if you made a human that did this, you would have a human that could refrain from eating much food for energy and instead choose to hang out in a nuclear reactor (they would still need to eat to take in nutrients, but would need fewer calories I guess?) ...but they'd also still get radiation poisoning / cancer / etc. Also, it isn't clear to me how these could be used to "clean up" messes anymore than sunbathers could clean up the sun. It seems they just absorb gamma rays, but nothing about them doing that should make that material decay faster... Maybe the idea is that they intake the radioactive particles and consolidate them so that cleanup then entails finding the fungus (which is presumably easier to visually locate) and scooping it all up? Maybe you could engineer the fungus to also bioluminescence strongly to aid in this.

fragsworth 13y ago
Likelihood of cancer may be related to the general chance of reproductive mutation, and the chance of reproductive mutation is also likely to be something that changes through evolution. If you have a species in a high-radiation environment, is it not possible that it evolves to have fewer reproductive mutations in general - and therefore lower chance of cancer?
- jlgreco 13y ago
  Yes, I think it makes sense that certain arrangements of DNA would be less susceptible to going cancerous than others. In one strand you might have a possible '1 bit flip' (I'm not a biologist in the slightest) change that would turn the routine into "while(1) {fork();}", but perhaps in another functionally equivalent strand you would need to flip 2 or 3 bits to get the same effect. So basically you want to select for DNA that has a large (DNA equivalent of) Levenshtein distance to cancerous DNA. Perhaps that is something that you could even deliberately engineer (though I don't think a general solution is possible since determining if DNA is cancerous might be the halting problem?) Maybe it would be easier to construct a strand of DNA that has the same effect as another strand of DNA, but with more error-checking. Throw in a bunch of asserts or something to send cells with DNA that fails the error checking into suicide mode...

hcarvalhoalves 13y ago

> What if we could genetically engineer ourselves to use this melanin pathway for ourselves? I can see this being totally feasible, more than the other approach, which would be to engineer ourselves to fix our own DNA: http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/6607 http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/dis...

hammock 13y ago

You might be surprised. Genetic engineering of our bodies is not necessary to take advantage of melanin's UV absorbent, antioxidant and radical scavenging properties. There have been a couple of "melanin" pills developed to that end. Of course they don't create energy for the body, though. They have also found it difficult to achieve final regulatory approval. http://en.wikipedia.org/wiki/Afamelanotide http://en.wikipedia.org/wiki/Afamelanotide http://en.wikipedia.org/wiki/Melanotan_II http://en.wikipedia.org/wiki/Melanotan_II