Can We Biologically Adapt to Outer Space (and Mars, Moon, etc)?

[sanman]

There is the idea that any harmful stressor, when experienced in lower, tolerable doses, can provoke living things into adapting to it and developing higher tolerance for it. Studies show this to be true not only for chemical toxins, but also for temperature and even radiation.

https://en.wikipedia.org/wiki/Hormesis

https://en.wikipedia.org/wiki/Radiation_hormesis

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2477686/

Certainly outer space offers various extreme conditions which can easily sterilize most forms of life familiar to us. So why see any small protection that hormesis can provide as being anything but a mere drop in the bucket? Perhaps because every bit helps, and because it might make the difference between barely surviving something vs overcoming it handily.


Are there currently, or should there be attempts to anticipatively expose prospective astronauts to increased low-level doses of stressors like radiation, to induce greater tolerance within them for space environments?

Possible stressors:

- Radiation

- Chemical toxins (eg. perchlorates in the non-bioremediated Martian environment)

- Lunar dust (microscopic shard-like properties)

Any others?

Could human populations settled off-world then over time develope adaptations to their larger environments?

Likewise, if future animals/livestock are bred on the Moon or Mars, would it be conceivable to adapt them to lunar or martian environments? (I dunno if at some point, after enough multi-generational breeding, they get classified as a different species or whatever- but I guess that's evolutionary adaptation rather than hormetic adaptation)

NOTE: I'm not talking about the raw ambient environments there, I'm just talking about living indoors but under the natural gravity conditions, elevated radiation, etc which we can't fully shield against

What are the beliefs on this?

[maryalice]

Yes, good luck on your thread. Personally I don't feel we will know until we attempt the first birth in space.
Mars could very well be the location. En route to or from Mars,,, off world......this will be the first start.

Who will be the next Eve?

[RDoc]

Of course we could adapt. Just give it either:

a) A few million years and billions of premature deaths
b) Serious genetic engineering (what could go wrong?)

[sanman]

Well, millions of years is a long time. What about within the lifespan of a single organism, like a human being?

Can we better adapt people on Earth to living in space, in advance of sending them there?
For instance, could we expose future astronauts to higher levels of radiation, to acclimatize them to a higher radiation tolerance?

Could we regularly give youngsters G-training, to help them develop tolerance to G-forces through repeated exposure? ("space camp")

Could we expose future colonists to perchlorates and other toxins, or lunar-type shard-like dust, in low doses to develop tolerance to those environments?

What are the optimal approaches to take for these things? Should it be done at a younger age, as close to the age of consent as possible? Should it be done round-the-clock in the months preceding launch?

To what extend could repeated cyclical exposure work?

[jbenton]

What are the beliefs on this?

I don't believe in evolution, so I can't help you there.


Just kidding.

Likewise, if future animals/livestock are bred on the Moon or Mars, would it be conceivable to adapt them to lunar or martian environments? (I dunno if at some point, after enough multi-generational breeding, they get classified as a different species or whatever- but I guess that's evolutionary adaptation rather than hormetic adaptation)

I would have to think a little more about humans adapting, but at least in the case of livestock, I would be surprised if any sort of natural adaption happens large-scale. Between selective breeding and genetic modifying, I think that - if there are any was to produce livestock better adapted to a lunar or martian colony environment - we'd force those changes on their offspring before we launch them.

[TripleSeven]

If humans are born, live and die in a less than 1 g world the body will respond to that...eventually given a long enough period of time, adaption will probably become genetic.  But every life will be affected by the change in G loads from conception to death.  How and if it is good or bad is the 54000 dollar question.

[Asteroza]

Lunar vacuum chickens strike me as not very suitable for BBQing. Probably...

Now lunar indoor goliath chicken blobs are another matter however...

[IRobot]

For instance, could we expose future astronauts to higher levels of radiation, to acclimatize them to a higher radiation tolerance?

Sure, read here:
https://en.wikipedia.org/wiki/Ramsar,_Mazandaran#Radioactivity

Regarding radiation and cancer, as someone unfortunately familiar with it, I'm seeing that the advances in the past 5 years were increadible and the ongoing research is extremely promising, to the point where cancer will become a simple disease to cure in 10-15 years, at least for the most common ones.

[Vahe231991]

A group of scientists in 2020 synthesized a new material, selenomelanin, that could potentially enable astronauts overcome any harmful radiation when traveling to Mars:
https://news.northwestern.edu/stories/2020/07/new-biomaterial-could-shield-against-harmful-radiation-selenomelanin/

[chopsticks]

Example of ChatGPT here? ^^

[Robotbeat]

A group of scientists in 2020 synthesized a new material, selenomelanin, that could potentially enable astronauts overcome any harmful radiation when traveling to Mars:
https://news.northwestern.edu/stories/2020/07/new-biomaterial-could-shield-against-harmful-radiation-selenomelanin/

after looking at this, I’m pretty sure this would have negative utility for space travel. It is specifically for x-ray shielding, so it is maximizing the amount of high atomic mass elements. This is literally the opposite of what you want for Galactic cosmic rays. I thought this was about improving biological repair of radiation damage, but I was wrong. It’s about blocking x-rays. This would be worse than nothing because the high atomic mass isotopes in it would cause high amounts of secondary radiation.

[Lampyridae]

A group of scientists in 2020 synthesized a new material, selenomelanin, that could potentially enable astronauts overcome any harmful radiation when traveling to Mars:
https://news.northwestern.edu/stories/2020/07/new-biomaterial-could-shield-against-harmful-radiation-selenomelanin/

after looking at this, I’m pretty sure this would have negative utility for space travel. It is specifically for x-ray shielding, so it is maximizing the amount of high atomic mass elements. This is literally the opposite of what you want for Galactic cosmic rays. I thought this was about improving biological repair of radiation damage, but I was wrong. It’s about blocking x-rays. This would be worse than nothing because the high atomic mass isotopes in it would cause high amounts of secondary radiation.

You could engineer for cosmic radiation shielding using body tissue for self-shielding, but that of course would leave your colonists looking like Baron von Harkonnen.

[sevenperforce]

Can we better adapt people on Earth to living in space, in advance of sending them there?

For some things, yes; for other things, no.

For instance, could we expose future astronauts to higher levels of radiation, to acclimatize them to a higher radiation tolerance?

To some degree, yes. Most biological radioresistance found in nature is a function of body plan and evolutionary bequest; species with slow or intermittent cellular reproduction rates (like arthropods, which undergo cellular reproduction and regeneration in accelerated spurts during molting) tend to do better than species with more rapid or otherwise constant cellular reproduction rates (like us). That's just an accident of body plan. We are not going to be able to "adapt" to do something that evolution has not bequeathed to us.

However, some radioresistance can be induced by successive exposures to small doses of ionizing radiation. Individuals working in the nuclear industries who have been subjected to small industrial doses of radiation over time have been shown to be more resistant to large, accidental doses. This is most likely due to an inherent selection mechanism: all cells have some self-repair capabilities, and the cells with more self-repair capabilities end up surviving mild doses of radiation, which ultimately results in their dominance. Of course this also means that cancers in such individuals will probably also be more resistant to radiation therapy, which is bad news.

Maximizing this effect would probably require successive doses to start early, during childhood, raising some thorny ethical questions.

And such induced radioresistance would not be heritable.

Could we regularly give youngsters G-training, to help them develop tolerance to G-forces through repeated exposure? ("space camp")

Yes, certainly.

Could we expose future colonists to perchlorates and other toxins, or lunar-type shard-like dust, in low doses to develop tolerance to those environments?

For some things with biological mechanisms of action, yes. The tetanus shot, for example, isn't a vaccination against the bacteria Clostridium tetani, but against the neurotoxin it produces. The body cannot adapt quickly enough to develop any natural resistance to C. tetani's neurotoxin, but exposure to an inactivated tetanus toxoid creates antibodies that will protect the body if a C. tetani infection takes place.

So it's possible that exposure therapy (or, more likely, vaccines) can be used to protect against some stuff. Against hazards with a physical rather than biological mechanism of action, not so much. Lunar dust toxicity is a result of dust shards physically penetrating lung cells; there's probably nothing the body can do to protect itself against that, any more than exposure to low doses of PFAS or asbestos protects the body from future larger doses.

[JohnFornaro]

Any others?

Um, gravity? 

Some of the several rotating AG space station threads feature designs where there are varying gravity levels for simulating Earth and Mars gravity.

I don't feel we will know until we attempt the first birth in space.

Under zero gee, the blastocyst doesn't develop properly.  My contention has been that we [mankind] will have to experiment empirically with both Earth and Mars AG to see if those births would be "normal".  It would be a new ethical challenge. 

There is not yet a body of biological knowledge which confirms that life under rotational AG is the same as life under the influence of an earthly massive body.

So yeah.  Who wants to be Eve?