Chernobyl Black Frogs Reveal Evolution In Action 63
German Orizaola and Pablo Burraco write via The Conversation: Our work in Chernobyl started in 2016. That year, close to the damaged nuclear reactor, we detected several Eastern tree frogs (Hyla orientalis) with an unusual black tint. The species normally has a bright green dorsal coloration, although occasional darker individuals can be found. Melanin is responsible for the dark color of many organisms. What is less known is that this class of pigments can also reduce the negative effects of ultraviolet radiation. And its protective role can extend to ionizing radiation too, as it has been shown with fungi. Melanin absorbs and dissipates part of the radiation energy. In addition, it can scavenge and neutralize ionized molecules inside the cell, such as reactive oxygen species. These actions make it less likely that individuals exposed to radiation will go on to suffer cell damage and increase their survival chances.
After detecting the first black frogs in 2016, we decided to study the role of melanin colouration in Chernobyl wildlife. Between 2017 and 2019 we examined in detail the colouration of Eastern tree frogs in different areas of northern Ukraine. During those three years we analysed the dorsal skin colouration of more than 200 male frogs captured in 12 different breeding ponds. These localities were distributed along a wide gradient of radioactive contamination. They included some of the most radioactive areas on the planet, but also four sites outside the Chernobyl Exclusion Zone and with background radiation levels used as controls. Our work reveals that Chernobyl tree frogs have a much darker colouration than frogs captured in control areas outside the zone. As we found out in 2016, some are pitch-black. This colouration is not related to the levels of radiation that frogs experience today and that we can measure in all individuals. The dark colouration is typical of frogs from within or near the most contaminated areas at the time of the accident.
The results of our study suggest that Chernobyl frogs could have undergone a process of rapid evolution in response to radiation. In this scenario, those frogs with darker colouration at the time of the accident, which normally represent a minority in their populations, would have been favoured by the protective action of melanin. The dark frogs would have survived the radiation better and reproduced more successfully. More than ten generations of frogs have passed since the accident and a classic, although very fast, process of natural selection may explain why these dark frogs are now the dominant type for the species within the Chernobyl Exclusion Zone.
After detecting the first black frogs in 2016, we decided to study the role of melanin colouration in Chernobyl wildlife. Between 2017 and 2019 we examined in detail the colouration of Eastern tree frogs in different areas of northern Ukraine. During those three years we analysed the dorsal skin colouration of more than 200 male frogs captured in 12 different breeding ponds. These localities were distributed along a wide gradient of radioactive contamination. They included some of the most radioactive areas on the planet, but also four sites outside the Chernobyl Exclusion Zone and with background radiation levels used as controls. Our work reveals that Chernobyl tree frogs have a much darker colouration than frogs captured in control areas outside the zone. As we found out in 2016, some are pitch-black. This colouration is not related to the levels of radiation that frogs experience today and that we can measure in all individuals. The dark colouration is typical of frogs from within or near the most contaminated areas at the time of the accident.
The results of our study suggest that Chernobyl frogs could have undergone a process of rapid evolution in response to radiation. In this scenario, those frogs with darker colouration at the time of the accident, which normally represent a minority in their populations, would have been favoured by the protective action of melanin. The dark frogs would have survived the radiation better and reproduced more successfully. More than ten generations of frogs have passed since the accident and a classic, although very fast, process of natural selection may explain why these dark frogs are now the dominant type for the species within the Chernobyl Exclusion Zone.
Peppered Moth (Score:5, Interesting)
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Just out of curiosity, how do you figure evolution works?
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Rather than repeat myself.
https://science.slashdot.org/comments.pl?sid=22148171&cid=62929707
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Or if you don't like it coming from me. https://pediaa.com/difference-between-natural-selection-and-evolution/
Re:Peppered Moth (Score:5, Informative)
The main difference between natural selection and evolution is that natural selection is the differential survival and/or reproductive success among the individuals within a species whereas evolution is the change in the heritable characteristics of a population over successive generations.
Keep reading until it clicks.
Natural selection happens to individuals. The changes it causes in a population over time is evolution.
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If only you had read your own link.
Keep reading until it clicks.
High 5. Love it when folks post links to material they very obviously don't understand that actually points out that they're wrong.
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He and apparently you are both idiots. Read past the high level summary, the aforementioned moths are literally used as an example of natural selection rather than evolution in that article.
As for the frogs in the story, there was no change across many generations for the general population and there is no new species. This is merely a handful of individuals seeing greater expression of genes seen in the greater (and unchanged) population.
Re: Peppered Moth (Score:2)
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It is also a mechanism incorporated in every competing model because natural selection is an obvious and easily observed phenomenon identified prior to the Theory of Evolution. We don't observe the bat bouncing backward when it hits a baseball and say it 'reveals General Relativity in action." We already had a model prior to GR that explained that behavior and while GR does recreate and explain the behavior GR an example of 'GR in action' is generally reserved for something related to observations GR was in
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It is also a mechanism incorporated in every competing model because natural selection is an obvious and easily observed phenomenon identified prior to the Theory of Evolution. We don't observe the bat bouncing backward when it hits a baseball and say it 'reveals General Relativity in action." We already had a model prior to GR that explained that behavior and while GR does recreate and explain the behavior GR an example of 'GR in action' is generally reserved for something related to observations GR was introduced to explain.
I think you should tell us what competing model you're referring to :)
Further, a bat bouncing backward when it hits a ball has nothing to do with GR. That's purely quantum mechanical.
Finally, because a thing was noticed before a theory was formulated does *not* mean the resulting theory is not demonstrated by that earlier thing. That doesn't even make any fucking sense.
Evolution is a model introduced to explain the formation of new species and large intraspecies changes. Neither is present here and these observations bolster Evolution no more than any other framework. Even ID incorporates natural selection.
No, it is not. You keep misconstruing what evolution is, I suspect, because you are an intelligent design proponent. Of the Young-Earth pe
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"Natural selection cares not if a phenotype spontaneously came into being via a random mutation, or was pre-existing."
This does not refute the assertion you are claiming is false. My point stands, natural selection must work on something that is already there.
"1) You consider evolution to be false.
2) You think God made men (and their lawns) as they are."
"Evolution is not some process that only happens when a speciation event does.
Evolution is the action that leads to speciation, cumulative change to heritab
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This does not refute the assertion you are claiming is false. My point stands, natural selection must work on something that is already there.
It flatly refutes it.
If a random mutation presents as a phenotype that increases reproductive fitness, then you have a brand new phenotype.
If your argument is that since that mutation worked on something that was there, then you *have* no argument. Because that's evolution.
That is all well and good for general references and expressions of faith in the current dominant model but not when looking at research which implies it does or does not support the edge cases that model poorly explains. For that we are looking for observed speciation events and/or (relatively) quick development of large (complex) changes intraspecies. Natural selection isn't the right answer here because natural selection isn't considered part of the PROCESS of Evolution, it is the right answer because it is the more specific answer.
Looking for speciation events is a nonsensical bar. There is no such thing. Speciation events occur over a period of time, generally longer than modern humans have even been around.
What you are trying to do, is call into question any k
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Read it again. Natural selection is the process that allows individuals to survive with advantageous traits. Evolution is when successive generations inherit advantageous traits. Do you know how the successive generations get those traits? Because their parents survived to breed. Their parents survived to breed...which is natural selection. Evolution happens because natural selection allows those parents to survive.
As for the frogs in the story there was change. It was a difference in melanin. Is that a dif
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More useful to talk about how many generations are required, rather than years, given the something like 100-1 (or more) ratio in generation time across all animal species.
A theoretical study [nih.gov] finds the answer to how fast new species can emerge (reproductively isolated due to genetic incompatibility) as little as 1000 generations, and on the order of several thousand more generally. We can see that within the human lineage new species can arise on the scale of a million years, with a 20 year generation time
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"Read it again. Natural selection is the process that allows individuals to survive with advantageous traits. Evolution is when successive generations inherit advantageous traits. Do you know how the successive generations get those traits? Because their parents survived to breed. Their parents survived to breed...which is natural selection. Evolution happens because natural selection allows those parents to survive."
You are using an overly broad definition of Evolution in this context. Natural selection an
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That is a summary, not a definition. There is more to the distinction.
The pepper moths mentioned in the post I replied to here are literally used as an example of natural selection in contrast to evolution in that article.
As for the frogs above, they did not experience a change across their population. Some individuals near the site are now seeing somewhat increased expression of existing genes. This is neither a new species nor a change across a critical mass of a general population which would redefine an
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That is a summary, not a definition. There is more to the distinction.
Nope.
The pepper moths mentioned in the post I replied to here are literally used as an example of natural selection in contrast to evolution in that article.
Wrong again.
They are used as an example of natural selection, for sure. Because they are. However, the distinction you draw is entirely in your own head.
To quote another site [butterfly-...vation.org] on the matter:
Since moths are short-lived, this evolution by natural selection happened quite quickly."
As for the frogs above, they did not experience a change across their population. Some individuals near the site are now seeing somewhat increased expression of existing genes. This is neither a new species nor a change across a critical mass of a general population which would redefine an existing species.
You're caught up in the speciation thing again. You're a YEC, aren't you?
Evolution does not need to define a new species to happen, that's a flatly false assertion.
What you're doing is begging the question. It's logically fallacious, and it makes it very difficult to take you seriously.
As for the frogs above, t
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"You're a YEC, aren't you?"
No idea what your undefined and unpopular acronym is supposed to refer to. I can only assume it is you, once again, injecting a logically impotent personal attack to compensate for your impotent member and weak position.
"Evolution is implicit in natural selection."
Talk about begging the question. Evolution is a larger framework which includes natural selection but it is not the ONLY framework which does or could include natural selection nor is the source of natural selection as b
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No idea what your undefined and unpopular acronym is supposed to refer to. I can only assume it is you, once again, injecting a logically impotent personal attack to compensate for your impotent member and weak position.
Let's google.
Result 1: Young Entrepreneur Council. Nope, probably not that.
Result 2: Young Entrepreneur Council.
Result 3: Young Entrepreneur Council.
Result 4: Young Earth Creationism... Aha.
Talk about begging the question. Evolution is a larger framework which includes natural selection but it is not the ONLY framework which does or could include natural selection nor is the source of natural selection as biological concept. Natural selection predates Darwin's work and influenced his work, not the other way around. Saying Evolution is implicit to natural selection is like saying gravity is implicit to string theory. It is only true in the sense that natural selection is an obvious and easily observed phenomenon that will be present or explained in EVERY framework which comes after.
Wow, you're not very bright.
It need not be the only framework that includes natural selection- that it does, and that it is accepted as the existing scientific theory for organism development over time, the statement "evolution is implicit in natural selection", is therefore a scientifically sound claim.
Whether or
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The model is that natural selection is the mechanism that causes evolution.
However, logically speaking, providing empirical evidence of natural selection at work only supports part of the model. It demonstrates changes of flexible attributes within a species, but not change across species. These frogs are darker in color, but clearly they are still frogs. Until they sprout wings and become a new species of flying-frog (or what-have-you), the evolution model itself has not been demonstrated.
This is someth
Re:Peppered Moth (Score:4, Informative)
These frogs are darker in color, but clearly they are still frogs. Until they sprout wings and become a new species of flying-frog (or what-have-you), the evolution model itself has not been demonstrated.
Flatly incorrect.
That is called speciation, which is of course one of the many paths evolution can take.
However, sticking with pure logic, the absence of empirical evidence that natural selection powers change-across-species is not, in and of itself, disproof.
There is no such lack of evidence. You have, in fact, just been presented with exactly such evidence.
The phenotype of the frogs (and moths in the upper example) changed to fit their environment. They evolved.
They evolved because natural selection made pairings of the new phenotype more successful.
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These frogs are darker in color, but clearly they are still frogs.
You really appear to not understand evolution. Are you under the impression that a green frog suddenly just POOF evolves into a black flying squirrel like some kind of Pokemon? Evolution occurs via natural selection over the course of many small changes over, typically, very long periods of time. First the frog turns black, for example, then it grows fur, then it grows wings, then it becomes warm blooded, then it grows different teeth, etc...until one day you have a black flying squirrel. But every little s
Pokemon evolution (Score:3)
These frogs are darker in color, but clearly they are still frogs.
You really appear to not understand evolution. Are you under the impression that a green frog suddenly just POOF evolves into a black flying squirrel like some kind of Pokemon?
Sadly, Pokemon evolution is probably the most popular theory of evolution. Pokemon evolution is really no more than the modernized version of long-standing myths about shapeshifting creatures.
Such myths might have been the reverse inspiration for evolutionary biologists to propose their gene centered theory of evolution [wikipedia.org], made popular by Richard Dawkins as the "selfish gene" theory. The focus on genes shifts evolution away from its association with werewolves and other magical beasts into the bland statisti
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You really appear to not understand my post.
No, I was never under the impression that evolution happens quickly, hence my mentioning of the fossil record as evidence of evolution. I think you were a bit quick in reading what you wanted to read, rather than what was there.
If one wants to demonstrate that natural selection produces (eventually) birds from fish (or what-have you), then one has taken on a significant burden. That isn't an easy thing TO demonstrate, since the process is so slow. Demonstrating
Re:Peppered Moth (Score:5, Informative)
I know where you're going to go with this. I've heard it before.
Natural selection is the process by which evolution occurs. I.e., evolution is an inevitable consequence of natural selection.
The moths/frogs, via natural selection, changed their heritable attributes (evolved).
Speciation is another part of evolution, but steps in between are still evolution.
Evolution is what you call the macroscale work of natural selection.
I.e., if natural selection selects for "darker frogs", evolution is what you call the population being replaced with darker frogs.
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Well, natural selection is the chief driver of evolution, sometimes simple random changes, with no benefit, drive speciation.
Consider song birds, colour and song are important in breeding. Two populations become separated, their songs and/or colours slowly change through random changes and eventually you have two populations that won't breed with each other. While the colour change might give an advantage such as better camouflage, slight changes in the song, likely no advantage and over generations those s
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Well, natural selection is the chief driver of evolution, sometimes simple random changes, with no benefit, drive speciation.
Completely fair- I didn't mean to imply otherwise.
Re: Peppered Moth (Score:1)
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Youâ(TM)re right of course, regardless of how many people on here disagree.
The real question is ⦠if you take the selected population out of their specialized environment and put them back into their original environment, are they more or less likely to survive? If they are less likely to survive in environments other than the specific one they were selected for, itâ(TM)s not evolution. Itâ(TM)s simply a loss of genetic diversity due to natural selection.
Where the heck do you get that idea? "If they are less likely to survive in environments other than the specific one they were selected for, it's not evolution." This is ridiculous...most creatures that evolved to survive new and unique environments would absolutely die if placed back in the environment where their ancestors originally came from. Panthers and lions have a common ancestor and at some point, likely when South America split from Africa, some prehistoric cats were left in Africa and others in S
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No matter how you try to constrain the definition of evolution to, what I suspect, is hide your creationist beliefs, you cannot change the real definition.
Evolution is change in the heritable characteristics of biological populations over successive generations [archive.org]
A loss of genetic diversity due to natural selection that results in a change of the population's phenotypes is evolution.
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This sounds very similar to the example of the Peppered Moth,...
This has some similarity, but some important differences. With the Peppered Moth the change in phenotype equilibrium was due to protection from existing predation driving the change. With the end of soot pollution the equilibrium shifted back and so did the more common light color form.
With these black frogs the change is a change that appears to have provided direct protection from a new environment hazard, acutely dangerous radiation levels, at the time of the accident. This created a persistence or perma
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I'll demonstrate.
With these black frogs the change is a change that appears to have provided direct protection from a new environment hazard
Becomes
With these black moths the change is a change that appears to have provided direct protection from a new environment hazard
That new environmental hazard is being eaten due to an inability to hide from predators.
All changes that lose their benefit are doomed to one day fall out of your genotype. When the radiation is gone, these frogs will lose their melanin as well.
How quickly that happens is a matter of generation length. With moths, it happens very, very quickly temporally speaking, because they have very short generation length.
Frogs, less so.
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As always, the best kind of correct is technically correct.
Re:Not Evolution (Score:4, Insightful)
Evolution would require the black frogs to be unable to breed with the lighter variety and produce viable offspring.
By whose arbitrary definition? If we went by that definition, lions and tigers .. which evolved apart for 3 or 4 million years aren't the product of evolution?
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And you're a sock puppet pretending to be rsilvergun. What is your point, exactly?
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The offspring of Lions and Tigers are sterile not viable. A result like that in Chernobyl frogs would be exactly the sort of thing I'm talking about.
Philosophical charity demands I point out there are better examples you could have chosen to make your point such as wolves and dogs. It is generally true that hybrids are not viable but there are exceptions and debates on how to resolve them.
Natural selection predates the Theory of Evolution, yes Evolution incorporates it but so do the notions of Darwin's cont
Re:Not Evolution (Score:4, Informative)
Evolution would require the black frogs to be unable to breed with the lighter variety and produce viable offspring.
Incorrect. You're referencing the Biological Species Concept which while often true, is not always true. Not all hybrids are sterile despite being the result of an inter-species breeding. Biology is complicated...so here's a kid's article on the topic:
https://kids.frontiersin.org/a... [frontiersin.org]
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Incorrect is far too strong a word indicating black and white that in this case masks 'generally true with a few exceptions.'
In any case, these frogs are not a new species at all. These are the same frogs with some localized individuals showing greater expression of a set of genes which are already common in the general population.
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Because 40 years of development and expression of a single new trait isn't enough to warrant a new species YET. No one said it was a new species, we said it was evolution. Y'all are the ones saying that just because it's not a completely new species that it can't be evolution in action and who are claiming that evolution can't have happened unless the frogs can't interbreed.
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And eventually. that may happen, especially if the white frogs have a hard time seeing black frogs to breed with them. Or maybe the population of white frogs some miles away slowly change their croak in a different way then the population of black frogs so they stop breeding, Then the populations continue to evolve in different directions until you have two species.
Remember that while natural selection is the main driver of evolution, there is also simple randomness, like slightly different croaks that rand
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Evolution would require the black frogs to be unable to breed with the lighter variety and produce viable offspring.
You're thinking of speciation.
No, Both are Pretty Well Known (Score:5, Informative)
Melanin is responsible for the dark color of many organisms. What is less known is that this class of pigments can also reduce the negative effects of ultraviolet radiation.
IME those two facts go pretty much hand-in-hand whenever and wherever they are taught (along with a note about Vitamin D).
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Came here to say this. Am leaving satisfied.
Radiation around Chernobyl (Score:2)
If the Russian soldiers putting themselves in the hospital from digging trenches didn't make people understand Chernobyl was still a nasty place this should.
Remember how natural selection works, the frogs turned black because the radiation was so bad that even the 'not quite pitch black' frogs were dying/failing to reproduce at a rate fast enough to knock them out of the gene pool.
Re:Radiation around Chernobyl (Score:5, Informative)
More likely, the frogs selected for black because they weren't so obvious to whatever hunts frogs there against the sooty ground (from the fires). Which we've seen in other places not involving "EVIIIL radiation".
I'm not quite sure if you're being serious or not.
You really think the ground has been covered with soot for 30 years??
Note that assuming the radiation turned the frogs black implies a level of radiation that would make Chernobyl worse than ground-zero at Hiroshima and Nagasaki...
Thanks for pointing me to an interesting question I hadn't actually thought about, turns out there's a simple answer: [gizmodo.com]
Little Boy had around 140 pounds of uranium, Fat Man contained about 14 pounds of plutonium and reactor number four had about 180 tons of nuclear fuel.
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If the Russian soldiers putting themselves in the hospital from digging trenches didn't make people understand Chernobyl was still a nasty place this should.
This finding is about how nasty it used to be, not how nasty it still is today.
"This colouration is not related to the levels of radiation that frogs experience today and that we can measure in all individuals. The dark colouration is typical of frogs from within or near the most contaminated areas at the time of the accident.
The results of our study suggest that Chernobyl frogs could have undergone a process of rapid evolution in response to radiation. In this scenario, those frogs with darker colouration
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If the Russian soldiers putting themselves in the hospital from digging trenches didn't make people understand Chernobyl was still a nasty place this should.
This finding is about how nasty it used to be, not how nasty it still is today.
"This colouration is not related to the levels of radiation that frogs experience today and that we can measure in all individuals. The dark colouration is typical of frogs from within or near the most contaminated areas at the time of the accident.
The results of our study suggest that Chernobyl frogs could have undergone a process of rapid evolution in response to radiation. In this scenario, those frogs with darker colouration at the time of the accident, which normally represent a minority in their populations, would have been favoured by the protective action of melanin. The dark frogs would have survived the radiation better and reproduced more successfully."
Or did you mean something else by "still"?
An interesting point.
I interpreted that to mean that the environment in the initially most contaminated areas was still most contaminated today.
But it may be that active selection largely stopped years ago.
Jurassic Pork (Score:1)
This recipe has been in my family since before the last glacial maximum:
Invite the shaman over for dinner, so he can purge the cave of evil influences while you cook. In a large stone pot, grind two fossilized dinosaur jarbils to a fine powder. Add two fresh pterosaur eggs and two piglets of bacon. Season to taste. Heat until the stench drives all the children out of the cave to huddle in the blizzard so they won't have to smell it. Then remove two sticks from the fire and cook slowly until people start coming back into the cave. Pass the time by trading lies with the shaman, maybe chewing on some sun-dried worms to keep the hunger pangs away.
Oh, and keep two stout spears and a heavy club within reach, because you're going to need them when dinner crawls out of the pot.
Seen This Effect (Score:2)
Starts with a radioactive spider bite, the next thing you know: Froggie - No Way Home!
Way more interesting question (Score:3)
Does this mean that people with a very dark skin color (not even just black but darker shades like many India nationals have) have an inherently greater resistance to radiation generally, not just UV?
I had never heard that before but the summary made it seem like this was widely known.
I really wonder what degree of protection this affords, if it would make much difference at all for serious amounts of radiation.
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Does this mean that people with a very dark skin color have an inherently greater resistance to radiation generally, not just UV?
Of course. External radiation, at least. But I'm not sure what use we can or should put this information to. Probably not nuclear cleanup crew recruitment.
17% larger than they were before (Score:1)
Here we go again⦠(Score:1)
â¦confusing evolution with natural selection.