Like our immunity system gets stronger against usual viruses and bacterias, can we evolute to grow more immune to radiation during generations? (I know it’s different things and responses, it’s just an example)
If yes, how?
If not, why?
In: Biology
The twins study with Scott Kelly showed his telomeres got longer with exposure to higher background radiation levels of the ISS. Our DNA does react and try and protect itself from radiation by making its ends longer. This is what some call garbage DNA, kinda sacrificial DNA, it gets destroyed from the radiation instead of the good DNA
Single person, no.
Gradually evolve resistance as a species? Possibly, if we were exposed to it enough. We’ve already evolved some resistance to the most common damaging radiation we experience – melanin to protect from sunlight.
The trouble with radiation is that it literally tears molecules apart. One big problem there being when the molecules in question are the DNA in our cells.
Bacteria and viruses can be fought off with molecules/proteins etc. our bodies produce. Radiation would need to be stopped from entering the body, or be absorbed by something that won’t cause us harm if it is destroyed by radiation.
As far as evolution goes, suddenly developing a radiation absorbing slime layer might reduce your chances of having offspring more than skin cancer in your 70s would.
Melanin is very good at blocking radiation.
That is the pigment in your skin, eyes, and hair.
Early humans had very high levels of melanin, due to being exposed to the hot African sun for long periods of time.
As man left Africa, and traveled to colder regions with shorter days, we lost that high level of melanin production because we didn’t need as much protection from UV. This lead to blue/green eyes, white skin, and blonde/red hair.
Humans that stayed in hot equatorial climates retained the dark skin, and humans that left lost the ability. Blue eyes and blonde hair are primarily from European branches of humanity, but melanin loss in the skin can be observed across the world.
On a related note, frogs in the Chernobyl exclusion zone have evolved black skin from generations of being exposed to high levels of radiation. The extra melanin makes them more likely to survive the harsh conditions.
In order to do it ourselves, we would need either advanced gene editing technology to be approved for use on humans, or generations of being exposed to high levels of radiation. Both of which are not really desirable.
TL;DR why would we want to when we can just avoid radiation/wear protective clothing
We are already really good at stopping harmful radiation.
Alpha is blocked by a sheet of paper, and cant even go through our retina. Don’t eat it and you are fine.
Beta is blocked by our skin. Don’t eat it and you are fine.
Gamma is super tiny. Try to stay away from it and you are fine.
If you are exposed to neutron, you are in a nuclear reactor or atomic bomb blast, and are not fine.
You’ll have to first define the kind of radiation. Some forms are less energetic than others. Cell phones and microwaves emit types of “radiation”
The high energy nuclear kind of radiation is more like a tiny bullet. Evolving to resist that kind of radiation seems unlikely, as stopping it requires significant shielding. And if living tissue is exposed to it, irreparable damage will occur.
The low energy kind is mainly hazardous when ingested. And if we are supposedly exposed to this kind of radiation regularly and early in life (in this evolution scenario) we’d have to assume it becomes ingested normally. The main risk associated with this is cancer. I’m not actually sure about evolving to resist that kind of exposure. We’d have to evolve mechanisms to prevent cancer basically. We are not simple organisms, so that kind of evolution might be complicated if not impossible.
https://en.m.wikipedia.org/wiki/Deinococcus_radiodurans#:~:text=Deinococcus%20radiodurans%20is%20a%20bacterium,Guinness%20Book%20Of%20World%20Records.
Here is an example of a species that has extreme resistance to radiation.
All species have to balance the amount of energy they put into repairing DNA and preventing mutations with the energy they put into other things, like growing, hunting, reproducing, and defending territory. The bacterial species described above reproduces incredibly slowly because it puts so much energy (calories) into the processes of repairing its DNA. In any circumstance where DNA damage is rare, it won’t do well compared to other bacteria. The other bacteria will grow faster, reproduce faster, and use up the environment’s resources to make more of themselves. But in an extreme environment like a desert, where there is a lot of solar radiation and other things (like dehydration) that damage DNA, all the regular bacteria will have their chromosomes destroyed beyond their ability to repair, while slow-growing Deinococcus Radiodurans will carefully and methodically repair all the DNA damage so that it can thrive.
All living things evolve to be able to do the right level of DNA repair for the environment they live in.
If the Earth were suddenly bombarded with 10,000x as much radiation, all of us big creatures would die out, and organisms like Deinococcus Radiodurans that possess ultra-high fidelity DNA repair mechanisms would all survive. If the radiation levels stayed high, then over the next billion years, their decendents would take over the world and give rise to new multi-cellular ‘plants’ and ‘animals’ that grow slow and spend a lot of energy on DNA repair.
I think we can live ultra long lives. Like a thousand years or more. We do not know how to do it fuck we are way behind. Our own bodies create cancer by replication and cancer is the killer the longer we live.
If the human species is still around 1000 years from now they will have a much different understanding on life and length of life. We will also understand Radiation differently.
What about the crabs in bikini atoll?
If by “radiation” you mean the ionizing radiation found as a result of radioactivity, it’s entirely possible. It’s actually already happened in Cryptococcus Neoformans, a fungus that’s been found growing in the shattered remains of Chernobyl reactor 4 that seems to be using the radiation there as a food source. (Please note that I don’t mean the remains of the reactor building, I mean it’s growing in the highly radioactive remains of the *reactor itself*.)
https://en.wikipedia.org/wiki/Cryptococcus_neoformans
So resistance to radiation come in a few different forms. One that is common is DNA repair enzymes or biological means to deal with damaged DNA. So at an ELI5 level if radiation damages the DNA it is sometimes possible for these enzymes to fix it, but not always. Some organisms have many more DNA repair enzymes and can be more resistant to radiation to an extent. The other process is a cell can detect something wrong with the DNA and basically kill itself so it doesn’t harm the organism Taking one for the team if you will.
Another thing some microbes do is shield their DNA from the damage of the radiation. In essence using some substance that will absorb the energy of the radiation before it damages the DNA. There is fungus that survives inside Chernobyl in high radiation environment that would be lethal to humans. It uses melanin, a molecule similar to that makes brown skin in humans (not melanin can come in different forms). And in fact melanin works to protect humans from UV radiation too. But the fungus noted above takes it to a much higher level. It is also thought this fungus uses radiation as an energy source for food too.
So we could theoretically evolve to handle more radiation but not be completely resistant though. As radiation levels get higher and higher there is too much damage being caused for a cell or organism to survive even with more of the protections noted above.
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