Radiotrophy

I was thinking more about radiotrophy, I think it’s a really interesting idea. Here’s an idea for mechanics for it, would love to know what everyone thinks.

  1. While planetary O2 is low and there is little Ozone layer it can work like a chloroplast, on surface patches there is some “cosmic radiation” amount and you can harvest it to make glucose.

  2. There can be radioactive rocks you find as you swim around. I think it would be cool to use the geiger counter sounds for it as they are so immediately communicative

Each rock has a max_intensity value. Each tick each rock generates a pulse of random intensity between 0 and it’s max_intensity value.

Each cell has a low radiation threshold and a high radiation threshold. The low is fixed and the high is the low + a constant multiplied by the number of melonin organelles you have. So if you have no melonin they are equal, if you have a lot then they are far apart.

The radiation dose you receive is the intensity of the pulse the rock sends out divided by your distance to it. If that received dose is less than your low threshold nothing happens, if it’s between your low and high you gain some glucose, if it’s above the high you take a little damage.

I hope that’s not too confusing. I think what this would mean is you would get this rattling geiger counter type pattern when near the rock. The player could then feel out the right distance to be based on how much glucose they were making vs how much damage they were taking.

For AI we could work out the right distance for each rock and each cell so that it could sit at just at the point where it would never take damage but would collect glucose. That is distance = max_intensity / high threshold.

Hopefully that would feel quite “radioactivey” and also be quite intuitive to figure out. All feedback welcome, not sure if this is a good idea.

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Oooh i like how this mechanic sounds, it’s very unique.
However, how will the player know that they’ll be damaged if they get too close but then they will get glucose if they are a bit further? What if the player gets near the rock without noticing it and then interprets that what harms them is staying too long and not too near? Specially if a geiger counter is playing. As someone who’s played Fallout that sound only means “get the heck away form here”.
Overall it looks very promising and i think these questions could be answered once we can use this mechanic in game.

I imagine all players would look at the tool tip before putting melonin on which might help them understand how to use it. I guess for any cell which doesn’t have melonin then the sound would mean get away.

Maybe the sound could change depending on if your cell sports melonin or not? The sound could be less hostile when your cell has melonins and isn‘t too near to the source of radioactivity.

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Hello sorry for disappearing for a week, this sounds great.

I made these two concepts for the mechanic, I’m not a fan of the “radioactive things glow” trope but since cells don’t have an actual vision and they detect chemicals i thought we could have some artistic licenses, think of the glow as some short of radiation vision.
Now, I have some questions about melanin. While it’s true that it’s used by some fungi to metabolize radiation we, who also use melanin, can’t do that. For realism sake, I thought about making two versions of melanin, one that only protects you against radiation (but gives you high resistance) and another that protects you and also gives you glucose. The problem is that this is too redundant and a version that gives you glucose has a higher incentive than just buying normal melanin.
I think it’s neat that we have a hazard and something to protect you against it, but i’m not sure about this protection also giving you a bonus.
Do you have any thoughts about this?

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I’ve had a bit of a look and I think that the melanin radiotrophs use is the same as that which other animals have, though I may well be wrong. Its says on wikipedia

“Some types of fungi, called radiotrophic fungi, appear to be able to use melanin as a photosynthetic pigment that enables them to capture gamma rays and harness this energy for growth.”

And it links to this paper which I think is just talking about regular melanin.

So I’m not so sure that it is a different thing, though maybe it is being used differently, I’m not sure how well understood radiotrophy is.

Talking of large animals with melanin though I think it’s a great example of something we could use for animals to be able to alter themselves on a cellular level meaningfully later in the game, which is great. I think stuff that ties cell edits to macro animal physiology is great and we need as many examples as we can get.

The difference between our melanin and the radiotrophic fungi is likely the same as the difference between chlorophyll and chloroplasts. Melanin is simply a pigment protein, and cannot actually generate any energy on its own. All it does is absorb a certain range of wavelengths of light. As a result of being built to absorb light, melanin provides colour to an organism.

Chlorophyll is the exact same, its simply a protein that absorbs light. If you want to actually harvest that light, you need to have additional proteins attached to the chlorophylls to create an overall light-harvesting machine. That’s what a chloroplast is.

So along the same lines, I think a good distinction to make would be to have Pigment Proteins or Melanin as one organelle, and what it does is protect an organism from harmful UV radiation. Then there’s a separate “Radioplast” organelle which specifically harnesses radioactive energy. Pigment Proteins and Radioplasts could cross-grade between each other, meaning an organism that already has pigment proteins could evolve one of them into a radioplast for cheaper than an organism evolving a radioplast from scratch.

In terms of the gameplay implications of radioplasts, how will we balance it with the other organelles? The main reason I wonder this is because before the Great Oxygenation Event (GOE) creates an ozone for the planet, the surface of the ocean is inhospitable to life because of the intense solar radiation. Even melanin is not enough to survive pre-GOE radiation levels on the surface. It’s only after the GOE leads to the formation of the ozone (as far as we know) that life evolved pigment proteins and migrated to the ocean surface. With radioplasts though, wouldn’t that take away the threat of solar radiation? Would it make it a no-brainer for an organism to evolve radioplasts?

Also, on the topic of sound effects, I’m unsure as to whether it would be good to have the geiger counter sound playing. It’s a very man-made sound to hear during the Microbe Stage.

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I think that is a very reasonable intuition. However the only evidence I can find is that it’s not a special type of organelle it’s just normal melanin. The wikipedia page links to this patent which is quite long but here’s some relevant sections:

The present invention provides a method of enhancing the
growth of an organism comprising increasing melanin con
tent in the organism to generate a melanized organism and
exposing the melanized organism to radiation to thereby
enhance the growth of the organism. The organism can be, for
example, a microorganism, a silk worm or a plant.

As used herein, a "melanized’ organism means an organ
ism in which the melanin content has been increased. The
organism can constitutively synthesize melanin, or be an
organism that does not constitutively synthesize melanin
where melanization is induced, for example, by providing one
or more genes required for melanin synthesis and/or the pre cursors for melanization.
The organism can be, for example, a microorganism, a silk
worm or a plant. The microorganism can be, e.g., a bacterium,
a plant, a protista, an algae or preferably a fungus. Suitable
fungi include, but are not limited to, Cryptococcus neofor
mans and Histoplasma capsulatum.

So I think it’s relatively clear they’re not talking about constructing some kind of special new organelle, it’s just using regular melanin.

I’m not sure I understand this because the GOE was caused by photosynthesizers right? But in order to do photosynthesis don’t they need to be bombarded by sunlight? How can they get enough light without getting too much cosmic radiation?

From the patent, which may be totally crazy,

It is possible that “radiosynthesis’ played an important role
during the early stages of life on Earth and that melanized
fungi were able to function as autotrophs—organisms
capable of making their own food. Given that terrestrial life
can capture visible electromagnetic radiation by photosyn
thesis, infrared radiation from geothermal ocean vents
and chemical energy from minerals, it is not Surprising that
Some organisms can also harness high energy photons by capturing them with melanin-type pigments. Radiosynthesis
provides the possibility of utilizing ionizing radiation as an
energy source for the Sustenance of life.

yeah this is a good point, I guess it depends if we can find a better sound which communicates well without being artificial. We could process a geiger counter type sound for example to be a spoosh and not a click or something.

My guess is that they are referring to melanin because it is the protein in the proposed “radioplast” that is doing the radiation absorption. Plus it sounds like the scientists don’t have the full details for what larger organelle or apparatus the melanin is a part of, so it’s easier to just refer to the melanin. Chemically though, melanin is the same whatever cell its found in, and its chemical function is limited only to absorbing light.

From what I recall, the photosynthesizers live right on the border of where the sunlight is enough to power their chloroplasts but not too much that the radiation damages them. Then, as the oxygen levels in the atmosphere increase and an ozone is formed, they are gradually able to live closer and closer to the ocean surface as the intensity of the damaging radiation reduces. Eventually it reduces to the point that they can live right on the surface and even in tidepools, estuaries, and rivers.

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In reference to the sound effect, we could use bubbling/boiling water. It would convey radioactive heating of the surrounding fluid, getting louder or with faster sizzle noises as the player approaches the rock. It would be a more natural counterpart to a Geiger sound

One issue with this though is that a player might associate the sound with a vent instead of a radioactive rock.

Also, I like the Geiger sound more than a boiling sound even if it does seem more man-made. Just my personal preference.

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Yeah nice. I think it’s a tricky one as the Geiger counter is not so thematic but also communicates extremely effectively.

Hello everyone,
I found an interesting article on representation of radioactive rocks. I share it with you.
http://www.geologyin.com/2015/02/top-radioactive-minerals-occurrence.html

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