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I'm no expert on this and this isn't a political post although it's been politicized, please don't beat me up. Can someone who is knowledgeable explain to me h
by phreenet 6y ago
I'm no expert on this and this isn't a political post although it's been politicized, please don't beat me up.
Can someone who is knowledgeable explain to me how this virus could have evolved in nature with such sensitivity to UV light? I've heard it explained that the driving belief that this virus was modified in a lab for study of SARS class viruses and escaped (not released, not as a weapon) is because it never had to adapt to sunlight. Is there a way that science could answer or prove this virus is in fact a natural mutation/evolution?
- function_seven 6y agoIf it spread among bats, I could see sunlight not being a selective pressure on the virus. They're nocturnal animals, right?
- eutectic 6y agoI would say it's a case of large surface area to volume ratio, inability to repair damage, and lack of selective pressure (why protect yourself from sunlight when you spend your time inside an animal?). No great mystery.
- gonzo41 6y agoWARNING Repeating a conspiracy theory I read : They think it came from underground Bats. And the whole "escaped" from lab thing was that a few Miners got sick years ago in a mine near Wuhan and the Lab there was the treating facility. At the time know one knew what they were dealing with so they quarantined and ....middle middle middle... Someone pulls out a corona virus for some bench top lab work a few years later and it gets out. END Conspiracy Maybe bats? Please don't beat me up :P
- beervirus 6y agoSunlight doesn't contain any 222 nm light. That's why there's no selection pressure for a virus to be able to survive irradiation at 222 nm.
- zamfi 6y agoThis is the probably the right answer. See e.g., this link https://commons.wikimedia.org/wiki/File:Solar_spectrum_en.svg https://commons.wikimedia.org/wiki/File:Solar_spectrum_en.sv... for what wavelengths of sunlight reach the earth’s surface.
- fluffernutter 6y agoNo. Sunlight contains ranges of UV, INCLUDING 222nm, but it is filtered before it gets to us. "Sunlight" is all light emitted by the sun, not just what gets to the ground. The reason this is important is because of words. The UV region covers the wavelength range 100-400 nm and is divided into three bands: UVA (315-400 nm) UVB (280-315 nm) UVC (100-280 nm). As sunlight passes through the atmosphere, all UVC and approximately 90% of UVB radiation is absorbed by ozone, water vapour, oxygen and carbon dioxide. UVA radiation is less affected by the atmosphere. Therefore, the UV radiation reaching the Earth’s surface is largely composed of UVA with a small UVB component. Also, 222nm isn't listed on the Internet as safe at all for humans given it exists in the "hard" UV range. While it may be that someone discovered that 222nm exactly doesn't penetrate skin, that doesn't mean their assertion is correct or is useful to us in this matter. I own a UVC bulb which makes me an expert on these matters. I can assure you that 222nm or whatever near it creates ozone, and you do not want to inhale that shit.
- beervirus 6y agoPretty clear from context that I'm talking about sunlight at the earth's surface.
- fluffernutter 6y agoTell that to an AI.
- mensetmanusman 6y agoAre you GTP-3?
- flatline 6y agoHow could the virus have spread worldwide with this sensitivity to sunlight? How could we have evolved from single celled organisms?
- Jaepa 6y agoWe know it wasn't lab made. We've know this since March. https://www.nature.com/articles/s41591-020-0820-9 https://www.nature.com/articles/s41591-020-0820-9 https://www.sciencealert.com/here-s-what-scientists-think-of-the-coronavirus-was-made-in-a-lab-rumour https://www.sciencealert.com/here-s-what-scientists-think-of...
- beervirus 6y agoAbsence of evidence is not evidence of absence. Now, realistically, it probably was not made in a lab. But it is not true that we know that.
- sjg007 6y agoThere's plenty of evidence it is not lab made.
- beervirus 6y agoThere's some evidence that is suggestive, but far from what anyone knowledgeable would consider proof.
- Falling3 6y ago> but far from what anyone knowledgeable would consider proof. Which is why the comment said "evidence" and not "proof".
- sjg007 6y agoRead the Nature paper.
- ClumsyPilot 6y agoIf you are going to be pedantic, there is no such thing as 'proof' at all. You can only ever demonstrate that you are 9X% likely to be correct. Maybe the murder caught on camera is a lost identical twin, or victim of a very elaborate frame-up. The standard for conviction is beyong reasonable doubt. What is reasonable? Maybe we have laws of physics wrong, and next tuesday sun will rise in the west, and Jesus rises from the dead. Again. Do yoy trust governments and scientists? They used to claik smoking is a great way to get your essential vitamins. Do you trust your own mind, because research has shown people can be manipulated into remembering things that never happened. Ib radical doubt, the only thing you can proove is 'I think, therefore I am".
- tyingq 6y agoUse of UV lamps as a germicidal goes back to the 1930's, so killing organisms with UV isn't new. Either the intensity, duration, or wavelength of the light could be different from sunlight.
- deleted 6y ago[deleted]
- giarc 6y agoAlmost all microorganisms as suspectible to UV light. The damage happens at the DNA level (UV light causes a thymine dimer when two thymine nuclobases are found together in DNA... thymine being the T in the AGCT of DNA code). This dimer can result in frameshift mutations which can result in a bunch of different damage depending on where the TT bases are (some mutations result in no change, some result in cells inability to replicate etc). So that's the background on how the UV light acts and disrupts a cells ability to survive. Now, about your question on how could a virus evolve if UV light kills it. Easy... the virus doesn't spend a ton of time outside of your body. Most transmission is person-to-person, there isn't a ton of person-to-surface-to-person spread therefore it's not like the virus is sitting on a handrail in the sun for days. Also, as I mentioned above, some mutations don't result in any change. There is a lot of redundancy in the DNA code (see DNA codon table 1). Not every combination produces a unique aminoacid. 1 - https://en.wikipedia.org/wiki/DNA_codon_table https://en.wikipedia.org/wiki/DNA_codon_table My microbiology background is a bit dated, so my facts might be a bit off here and there.
- zeta0134 6y agoAlso it's really important to conceptualize the sheer scale at which a virus operates. One single virus isn't a problem, but when it enters the host's body and replicates, you're talking about millions of the little things. Some of them will die off to all sorts of natural causes and that's (from the virus's point of view) not a problem so long as enough of them survive to continue replicating, in their host, in some adjacent host, etc.
- supernova87a 6y agoI guess this is the science behind the statement "sunlight is the best disinfectant" through the ages.
- giarc 6y agoCorrect. Since UV light acts at the molecular level and at the very core of what makes the cell work (DNA or RNA) it's hard for organisms to overcome. There are mechanisms of fixing these dimers, but cells need to produce them (which uses resources). Therefore there is a trade off, create too many fixes and something else has to give, create too little and a little UV light kills you.
- deleted 6y ago[deleted]
- achenatx 6y agoall viruses are susceptible to UV light. Ultimately it spread in bats so it is pretty obviously able to spread in caves. It also spread in people indoors. There is virtually no way for scientists to look at DNA and say "oh yeah this was manmade" (or not manmade). Possibly if there is some really obvious splicing marker used or something. the entire sequence can be put into a computer and custom generated.
- groby_b 6y agoThere are, however, strong indications. I don't have my cites handy, but IIRC for COVID, they were twofold. One, it relied on a mechanism that pre-COVID was considered ineffective/borderline for spread, and that actually doesn't work well in simulations - so it's unlikely humans would've picked that. Two, it's closer to typical bat viruses than typical coronaviruses - again, an unlikely choice for humans to make. Ah, here we go: https://www.livescience.com/coronavirus-not-human-made-in-lab.html https://www.livescience.com/coronavirus-not-human-made-in-la... No, that doesn't rule out manmade 100%, but it makes it quite unlikely. It's essentially saying "hey, I built a virus in a structure that doesn't rely match a well-working virus class. Also, it completely fails to do what we want to do in simulations. We should invest a lot of money to build that". Occam's barbershop would like to point out the very high number of unlikely events required to go down that path ;)
- belltaco 6y ago>with such sensitivity to UV light I don't think the sensitivity is specific to COVID-19. I believe it extends to all coronaviruses, if not all flu viruses.
- scotty79 6y agoYou could ask how humans evolved in a world that is mostly water and humans drown so easily. They are also present in regions surrounded by water? How did they get there? They developed in places that are not water and moved to other places through water by occupying small spots of non-water while in transit. Same with the virus. It developed in places that UV doesn't reach, like insides of larger living things, and travel to other habitable places by exposing themselves to UV only very briefly while being somewhat shielded by water in breathed out droplets.
- m463 6y agoYou just described bats that live in caves, like vampires and only come out at night.
- loudmax 6y agoMy understanding is that this coronavirus originally evolved to infect bats. Presumably, bat to bat transmission would be mostly at night, so not much evolutionary pressure for the virus to last long in sunlight.
- djsumdog 6y agoI thought the bat thing ended up being untrue?
- peter303 6y agoIt hypothesized that cellular life evolved in deep, dark, warm places in the ocean. Geoboiologist Robert Hazen experimentally found that most stages of basic metabolic citric cycle and RNA reactions do not require enzyme catalysts to proceed there. Then as life expanded to cold, low pressure bright sunlight areas they developed enzymes to assist metabolism and protein synthesis there. Most viruses dont contain the mechanisms to resist damaging solar radiation