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Temperature tolerance of organisms

 
 
 
Since we're now talking about horrible ways to treat creatures, there was a passing fad when I was a kid in Scotland, way back in the 1960s. We grew up on the coast, and a perennial nuisance was the hordes of Sea Gulls that shat everywhere, and were aggressive stealers of food. We called then Shite-Hawks.

The (horrible) fad was to take pellets of Calcium Carbide and wrap them in small bits of bread, and throw them to the gulls, who wolfed then down ravenously. However, Calcium Carbide when mixed with acid - like stomach acid - gives rise to very rapid generation of Acetylene gas. The gulls used to literally explode.
This was, of course, appalling, and way before gulls became protected species.
 
steve_bank said:
NASA dud an experiment. They sent bacteria into space exposed to vacuum and ambient radiation. Th bateria formed a hard shell. Returned to Earth came back to life.
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There are lots of sporeforming bacteria, so these bacteria could have been some of them. I'd have to see more details to be sure of that.
 
lpetrich said:
steve_bank said:
NASA dud an experiment. They sent bacteria into space exposed to vacuum and ambient radiation. Th bateria formed a hard shell. Returned to Earth came back to life.
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There are lots of sporeforming bacteria, so these bacteria could have been some of them. I'd have to see more details to be sure of that.
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I saw it on a PS show, I'll see if I can find a reference.
 
 Extremophile lists several extreme conditions that some organisms are known to metabolize, grow, and reproduce in.
  • Temperature
    • High
    • Low
  • Concentration
    • Dryness
    • Acidity
    • Alkalinity
    • Salinity
  • Radiation
    • Ionizing radiation
    • Ultraviolet light
  • Pressure

For the low end of temperature tolerance, some organisms get beyond the -20 C limit for activity by cheating. Polar bears and emperor penguins can stay active in temperatures less than -30 C, but they maintain body temperatures around +37 C for the bears and +38 C for the penguins. They do that with layers of insulation. Their skins have thick fat layers or blubber, and on their skins is hair or feathers.

Tolerance of high levels of ionizing radiation seems like an oddity -- what would make organisms able to survive something that they have experienced only very recently? Deinococcus radiodurans is a bacterium that can survive doses a thousand times greater than doses that will kill us. Yet such doses are very recent and in very restricted environments. This bacterium does that by having very active gene-repair mechanisms, an adaptation to a much older and much more common hazard: dryness.
 
lpetrich said:
 Extremophile lists several extreme conditions that some organisms are known to metabolize, grow, and reproduce in.
  • Temperature
    • High
    • Low
  • Concentration
    • Dryness
    • Acidity
    • Alkalinity
    • Salinity
  • Radiation
    • Ionizing radiation
    • Ultraviolet light
  • Pressure

For the low end of temperature tolerance, some organisms get beyond the -20 C limit for activity by cheating. Polar bears and emperor penguins can stay active in temperatures less than -30 C, but they maintain body temperatures around +37 C for the bears and +38 C for the penguins. They do that with layers of insulation. Their skins have thick fat layers or blubber, and on their skins is hair or feathers.

Tolerance of high levels of ionizing radiation seems like an oddity -- what would make organisms able to survive something that they have experienced only very recently? Deinococcus radiodurans is a bacterium that can survive doses a thousand times greater than doses that will kill us. Yet such doses are very recent and in very restricted environments. This bacterium does that by having very active gene-repair mechanisms, an adaptation to a much older and much more common hazard: dryness.
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Restricted environments, sure. but hardly "very recent".

https://en.m.wikipedia.org/wiki/Natural_nuclear_fission_reactor

There are plenty of naturally very radioactive places on Earth, and in general, radioactivity was greater in the distant past.

It makes a lot of sense for organisms to evolve to take advantage of such niches. After all, most extreme environments have their specialised inhabitants.
 
lpetrich:
Warm-bloodedness itself likely evolved for resistance to disease organisms, something that likely also explains fevers. So being warm-blooded (homeothermic, endothermic) is sort of like having a permanent fever.
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Such speculations are difficult, but I very much doubt that this was the driving force behind the evolution of 'warm-bloodedness' (technically homeothermy, or perhaps endothermy, depending on what aspect of temperature regulation is being emphasized). Note that 'cold-blooded' animals may sometimes have rather warm body temperatures. The most obvious advantages to being a homeotherm are maintaining activity levels in low temperatures, and optimizing metabolism for a narrow range of temperatures. The most obvious disadvantages are increased energy requirements, and lowered tolerance to changes in body temperature.

Peez
 
bilby said:
lpetrich said:
Tolerance of high levels of ionizing radiation seems like an oddity -- what would make organisms able to survive something that they have experienced only very recently? Deinococcus radiodurans is a bacterium that can survive doses a thousand times greater than doses that will kill us. Yet such doses are very recent and in very restricted environments. This bacterium does that by having very active gene-repair mechanisms, an adaptation to a much older and much more common hazard: dryness.
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Restricted environments, sure. but hardly "very recent".

https://en.m.wikipedia.org/wiki/Natural_nuclear_fission_reactor
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Titled link with "wiki" tag:  Natural nuclear fission reactor -- there is only one example known, in Oklo, Gabon. It has some 16 sites where nuclear reactions ran for a few hundred thousand years some 1.7 billion years ago. Its energy-release rate was likely around 100 kilowatts over the whole time.

From that article, that natural nuclear reactor consumed about 5 tons of U-235. This was about 0.1 - 0.3% of the total uranium content of the rocks, meaning 1,500 - 5,000 tons of uranium total. So there was at least 1000 cubic meters of uranium ore. 100 kilowatts means about 0.1 joules / cubic meter / second or 0.1 gray / second if it is all delivered as ionizing radiation. If only 1% is, likely from most of the fission energy going into the kinetic energy of the separating fission-product nuclei, then the radiation dose would be 0.001 gray / second. That's closely related to 0.001 sievert / second. Deinococcus radiodurans could easily survive this dose.

But there is the problem of what might sustain the resistance to such large radiation doses over the last 1.7 billion years. Checking on  Sievert and  Orders of magnitude (radiation), the typical background-radiation dose is about 10^(-7) sievert / second. The most radioactive inhabited places, Guarapari, Brazil, and Ramsar, Iran, get to a bit less than 10^(-5) sievert / second. That's much less than Oklo-scale radioactivity, let alone levels of radioactivity that would kill almost everything but D.r.

There are plenty of naturally very radioactive places on Earth, and in general, radioactivity was greater in the distant past.
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They aren't very radioactive, as I've discovered.
 
That's teeny tiny compared to what D.r. can survive.

The weakness of this and other environmental ionizing-radiation sources means that this organism's extreme radiation tolerance must have been a side effect of adaptation to something else. It's not just D.r., there's a recently-discovered organism with even more radiation tolerance: Thermococcus gammatolerans.

Wikipedia:  Deinococcus radiodurans,  Thermococcus gammatolerans
MicrobeWiki: Deinococcus radiodurans - microbewiki, Thermococcus gammatolerans - microbewiki
 
I started a three on a fungus found inside rhea Chernobyl reactor that lives on radiation, a variant of photosynthesis. On mutation all's it takes is one particle corrupting DNA/genes.

https://study.com/academy/lesson/what-is-photosynthetic-fungi.html

High energy X and Gamma EM radiation is iodizing and mutagenic. I have heard it prosed that a Gamma Ray Burst could have affected evolution.
.
https://en.wikipedia.org/wiki/Gamma_ray
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1203310/

I read about a radiation experiment with dragonflys that can induce an extra set of wings.
 
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Well you would expect an organism that can repair molecular damage from heat, free radicals, or both, to also be able to repair damage from ionizing radiation - there's nothing fundamentally different about a DNA strand that was broken by oxidization from free radicals, and one broken by being clobbered with an alpha particle, after all.
 
Elixir said:
Nobody mentioned Tardigrades (Water Bears)? ...
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But tardigrades can do cryptobiosis or suspended animation, and I'm sure that its higher resistance numbers are for being in that state. That's the case for other organisms also. So be careful.
 
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