7 ms·

Chernobyl black frogs reveal evolution in action

154 points by gwbas1c 4y ago

robocat 4y ago
The article doesn’t say whether they are just black on the skin, or black throughout the body. Melanin throughout the body could perhaps help protect a little against some ingested radioactive substances (given the mechanisms listed). However I am guessing the the existing genetic variation was for skin colour, so only the skin colour was likely to be selected for (given the small number of generations).
- gus_massa 4y ago
  Almost sure it's only the skin. [But I can't find a good source.]
aaron695 4y ago
phtrivier 4y ago
I guess they'll get a couple of new ecosystems soon ? (Probably worth the downvotes. Should we still care ?)
_tom_ 4y ago
I dislike sites, like phys.org, that don't have a proper "opt out" from tracking. I encourage people to not visit them.
- daniel-cussen 4y ago
  Yeah directly against this site's guidelines I can't click on links anymore because they are so rapey. They want me to consent to anything in exchange for reading for 30 seconds? Do they have any idea what that word means? Like going to do pagerank with consent cookies, filter anything with a consent cookie, and anything that links to anything with a consent cookie, see what's left.
- bin_bash 4y ago
  You might consider the fanboy annoyance list which blocks the cookie dialog: https://fanboy.co.nz/ https://fanboy.co.nz/ Practically I'm not really sure what this does in terms of actual tracking but personally it's the dialog that annoys me more.
- ASalazarMX 4y ago
  I just right-click and open them in a private window, and accept all cookies. They can sell a new visitor, and I get to read the content.
  - AshamedCaptain 4y ago
    Note that you are not just accepting cookies, but _tracking_ overall.
    - ASalazarMX 4y ago
      I'm aware of that. I used to dedicate a Firefox container to these sites so they can track between themselves, but that's basically private browsing with extra steps. Private browsing, an ad blocker, and a cookie manager for when I want to scrub a site/container is the best compromise I can find right now. I care for my privacy, but the pressure of spyware is everywhere, at multiple levels, and the effort required to counter it completely is excessively asymmetrical.
yayitswei 4y ago
Tldr for those opting out of tracking: melanin protects from cell damage due to radiation, frogs found inside the contamination zone were darker than those outside.
- an1sotropy 4y ago
  and it happened in about 10 generations, which is zippy for evolution
  - deleted 4y ago
    [deleted]
  - MonkeyMalarky 4y ago
    Well it's not relying on evolution coming up with an entirely new chemical or protein, in this case it is increased expression of one the frogs already have. Still super fascinating to think we have innate, multipurpose radiation protection.
    - an1sotropy 4y ago
      right, and the fun only really starts when the black frogs stop mating with the green ones; I don’t think that (speciation) was mentioned in the article
  - josefresco 4y ago
    > which is zippy for evolution I feel like I hear this a lot - I wonder if our hypotheses about the "natural" speed of evolution are wrong.
    - akiselev 4y ago
      > our hypotheses about the "natural" speed of evolution are wrong There's so much to unpack in that sentence! :) In general, a layman's understanding of a complex scientific topic is going to be wrong but if we restrict "our hypotheses" to evolutionary biologists, then no. Between the (very popular) equilibrium hypothesis that a sibling linked to, microbiology, and the textbook cases of evolution during the industrial revolution [1], biologists have known for a long time that natural selection can be fast or slow. Regarding "natural" and tying back into the equilibrium hypothesis: non-cyclical rapid changes to the environment used to be much rarer before humans began building civilization, so pre-historic evolution might have looked significantly different. Nowadays, all it takes is a single ship to accidentally transport an invasive species that will wipe out an ecosystem and leave only the ones best adapted to the new reality. Last but not least, the "speed" of evolution is actually a combination of two orthogonal factors: the mutation rate and selection pressure. Natural selection can only select from the species that exist (i.e. the ones already surviving) so mutation rate is really what most people mean when they say "speed of evolution". Chernobyl is a very special case where the radioactive fallout increases the mutation rate, reduces lifespans by an average of 30% (IIRC) putting more pressure on survival to sexual maturity, and removes much of human interference from the picture. I wouldn't draw many conclusions on evolutionary biology from Chernobyl unless we plan on turning the entire planet into a fallout zone. [1] https://en.wikipedia.org/wiki/Peppered_moth_evolution https://en.wikipedia.org/wiki/Peppered_moth_evolution
baron816 4y ago
Still just two eyes though.
- layer8 4y ago
  I guess some Simpsons episodes will have to be revised.
KasianFranks 4y ago
"In addition, it opens the doors to promising applications in fields as diverse as nuclear waste management and space exploration."
OrvalWintermute 4y ago
There are at least three errors in the article: (1) This is adaptation, not evolution, but it may be merely selection of a pre-existing color variant that already widely found in nature. We have the same exact variation of melanistic toads & frogs found in the US. (2) They really don't know how many generations this occurred over, they have a measurement, and a measurement. (3) The baseline wasn't built before the Cherynobyl event. As a person that has caught a great number of frogs and toads, their coloration in normal areas varies greatly based on the local Flora and sun conditions. The very dark / black frogs which are already found in nature, may have just reproduced better, instead of coloring adaptation being introduced. Frogs that live near asphalt and post-wildfire conditions would be expected to have better survival characteristics due to decreased visibility.
- UncleOxidant 4y ago
  So it would seem this gene for melanin already existed in the gene pool of these frogs - it's not like the radiation caused a mutation that led to this. So that's what makes it adaptation vs evolution? (where the latter would be an entirely new gene that arises that wasn't in the population before?)
  - pazimzadeh 4y ago
    They are not claiming that the radiation led to evolution of an entirely new gene..that would be unprecedented. You don't get "brand new genes" in that kind of evolutionary time frame. Also, there is not single gene for melanin. Several genes are required for the ultimate effect that you observe as dark skin. A mutation in any of these genes, or in any of the transcription factors which control expression of these genes, could lead to observed differences in frog skin color. FYI, "new genes" are usually the result of duplication of an existing gene (https://en.wikipedia.org/wiki/Gene_duplication#Mechanisms_of_duplication https://en.wikipedia.org/wiki/Gene_duplication#Mechanisms_of...). Duplicating a gene can be useful in and of itself by providing functional redundancy. However, the new copy is then also subject to its own mutations without affecting the original copy, and over time the two genes may diverge in function.
swayvil 4y ago
It seems to be a good argument for Lamarckism. Some kind of "genetic intelligence". I wonder how the probability weighs out.
- deleted 4y ago
  [deleted]
- zasdffaa 4y ago
  Maybe. What mechanism though. Compare with evolution whose mechanism is mostly known and well understood. Why pick the former when the latter works.
  - pazimzadeh 4y ago
    Epigenetics - the ability to switch certain genes on and off without changing the genetic information (like commenting out certain lines of code) based on environmental cues.
    - zasdffaa 4y ago
      I'm aware of epigenetics via methylation
      - pazimzadeh 4y ago
        Well there's your mechanism. I don't understand "Why pick the former when the latter works." No one is picking anything, it's all happening simultaneously. An epigenetic solution would reduce selective pressure for a genetic solution, theoretically.
        zasdffaa 4y ago
        Because the former mechanism, for lamarkism, wasn't given, and Some kind of "genetic intelligence" is just a vacuous proposition, so why raise it. Your mention of epigenetics was a sensible suggestion in that at least it's known to happen (although whether it can control skin colouring is another matter)
calibas 4y ago
If melanin protects against ionizing radiation, does that apply to humans as well? And does that mean darker-skinned human beings are better suited for space travel?
- BurningFrog 4y ago
  Yes, people have melanin in the skin to protect from damaging sunlight. Whiter skin evolved when humans migrated from Africa to regions with less sun, in order to get more vitamin D.
  - tw20212021 4y ago
    So we all started black?
    - BurningFrog 4y ago
      I don't think we have any skin samples from back then, but yes, that is almost certainly the case.
    - saiya-jin 4y ago
      Not sure if you are joking, but that's by far the most probable option. Just look at civilizations living for millenia near equator, be it Africa, isolated islands in Indian ocean (ie Nicobar) or native Australians. Planet was colder, and around equator you actually have quite habitable places even now, deserts are further from equator. But you get tons of light whole year in very stable pattern.
    - samatman 4y ago
      What's started? We had fur at one point, and our still-furred cousins have pink skin, so our ancestors probably did as well. It's generally believed to be the case that dark skin evolved with hairlessness, and was lost by some branches of the tree during the glacial period.
      - sdflhasjd 4y ago
forgotmypw17 4y ago
https://archive.ph/JRvlJ https://archive.ph/JRvlJ
- adolph 4y ago
  Also https://onlinelibrary.wiley.com/doi/10.1111/eva.13476 https://onlinelibrary.wiley.com/doi/10.1111/eva.13476 No genetics were done. Measurements of a sample of 189 only.

154 points by gwbas1c 4y ago

The article doesn’t say whether they are just black on the skin, or black throughout the body. Melanin throughout the body could perhaps help protect a little against some ingested radioactive substances (given the mechanisms listed). However I am guessing the the existing genetic variation was for skin colour, so only the skin colour was likely to be selected for (given the small number of generations).

gus_massa 4y ago
Almost sure it's only the skin. [But I can't find a good source.]

aaron695 4y ago

phtrivier 4y ago

I guess they'll get a couple of new ecosystems soon ? (Probably worth the downvotes. Should we still care ?)

_tom_ 4y ago

I dislike sites, like phys.org, that don't have a proper "opt out" from tracking. I encourage people to not visit them.

daniel-cussen 4y ago
Yeah directly against this site's guidelines I can't click on links anymore because they are so rapey. They want me to consent to anything in exchange for reading for 30 seconds? Do they have any idea what that word means? Like going to do pagerank with consent cookies, filter anything with a consent cookie, and anything that links to anything with a consent cookie, see what's left.
bin_bash 4y ago
You might consider the fanboy annoyance list which blocks the cookie dialog: https://fanboy.co.nz/ https://fanboy.co.nz/ Practically I'm not really sure what this does in terms of actual tracking but personally it's the dialog that annoys me more.
ASalazarMX 4y ago
I just right-click and open them in a private window, and accept all cookies. They can sell a new visitor, and I get to read the content.
- AshamedCaptain 4y ago
  Note that you are not just accepting cookies, but _tracking_ overall.
  - ASalazarMX 4y ago
    I'm aware of that. I used to dedicate a Firefox container to these sites so they can track between themselves, but that's basically private browsing with extra steps. Private browsing, an ad blocker, and a cookie manager for when I want to scrub a site/container is the best compromise I can find right now. I care for my privacy, but the pressure of spyware is everywhere, at multiple levels, and the effort required to counter it completely is excessively asymmetrical.

yayitswei 4y ago

Tldr for those opting out of tracking: melanin protects from cell damage due to radiation, frogs found inside the contamination zone were darker than those outside.

an1sotropy 4y ago
and it happened in about 10 generations, which is zippy for evolution
- deleted 4y ago
  [deleted]
- MonkeyMalarky 4y ago
  Well it's not relying on evolution coming up with an entirely new chemical or protein, in this case it is increased expression of one the frogs already have. Still super fascinating to think we have innate, multipurpose radiation protection.
  - an1sotropy 4y ago
    right, and the fun only really starts when the black frogs stop mating with the green ones; I don’t think that (speciation) was mentioned in the article
- josefresco 4y ago
  > which is zippy for evolution I feel like I hear this a lot - I wonder if our hypotheses about the "natural" speed of evolution are wrong.
  - akiselev 4y ago
    > our hypotheses about the "natural" speed of evolution are wrong There's so much to unpack in that sentence! :) In general, a layman's understanding of a complex scientific topic is going to be wrong but if we restrict "our hypotheses" to evolutionary biologists, then no. Between the (very popular) equilibrium hypothesis that a sibling linked to, microbiology, and the textbook cases of evolution during the industrial revolution [1], biologists have known for a long time that natural selection can be fast or slow. Regarding "natural" and tying back into the equilibrium hypothesis: non-cyclical rapid changes to the environment used to be much rarer before humans began building civilization, so pre-historic evolution might have looked significantly different. Nowadays, all it takes is a single ship to accidentally transport an invasive species that will wipe out an ecosystem and leave only the ones best adapted to the new reality. Last but not least, the "speed" of evolution is actually a combination of two orthogonal factors: the mutation rate and selection pressure. Natural selection can only select from the species that exist (i.e. the ones already surviving) so mutation rate is really what most people mean when they say "speed of evolution". Chernobyl is a very special case where the radioactive fallout increases the mutation rate, reduces lifespans by an average of 30% (IIRC) putting more pressure on survival to sexual maturity, and removes much of human interference from the picture. I wouldn't draw many conclusions on evolutionary biology from Chernobyl unless we plan on turning the entire planet into a fallout zone. [1] https://en.wikipedia.org/wiki/Peppered_moth_evolution https://en.wikipedia.org/wiki/Peppered_moth_evolution

baron816 4y ago

Still just two eyes though.

layer8 4y ago
I guess some Simpsons episodes will have to be revised.

KasianFranks 4y ago

"In addition, it opens the doors to promising applications in fields as diverse as nuclear waste management and space exploration."

OrvalWintermute 4y ago

There are at least three errors in the article: (1) This is adaptation, not evolution, but it may be merely selection of a pre-existing color variant that already widely found in nature. We have the same exact variation of melanistic toads & frogs found in the US. (2) They really don't know how many generations this occurred over, they have a measurement, and a measurement. (3) The baseline wasn't built before the Cherynobyl event. As a person that has caught a great number of frogs and toads, their coloration in normal areas varies greatly based on the local Flora and sun conditions. The very dark / black frogs which are already found in nature, may have just reproduced better, instead of coloring adaptation being introduced. Frogs that live near asphalt and post-wildfire conditions would be expected to have better survival characteristics due to decreased visibility.

UncleOxidant 4y ago
So it would seem this gene for melanin already existed in the gene pool of these frogs - it's not like the radiation caused a mutation that led to this. So that's what makes it adaptation vs evolution? (where the latter would be an entirely new gene that arises that wasn't in the population before?)
- pazimzadeh 4y ago
  They are not claiming that the radiation led to evolution of an entirely new gene..that would be unprecedented. You don't get "brand new genes" in that kind of evolutionary time frame. Also, there is not single gene for melanin. Several genes are required for the ultimate effect that you observe as dark skin. A mutation in any of these genes, or in any of the transcription factors which control expression of these genes, could lead to observed differences in frog skin color. FYI, "new genes" are usually the result of duplication of an existing gene (https://en.wikipedia.org/wiki/Gene_duplication#Mechanisms_of_duplication https://en.wikipedia.org/wiki/Gene_duplication#Mechanisms_of...). Duplicating a gene can be useful in and of itself by providing functional redundancy. However, the new copy is then also subject to its own mutations without affecting the original copy, and over time the two genes may diverge in function.

swayvil 4y ago

It seems to be a good argument for Lamarckism. Some kind of "genetic intelligence". I wonder how the probability weighs out.

deleted 4y ago
[deleted]
zasdffaa 4y ago
Maybe. What mechanism though. Compare with evolution whose mechanism is mostly known and well understood. Why pick the former when the latter works.
- pazimzadeh 4y ago
  Epigenetics - the ability to switch certain genes on and off without changing the genetic information (like commenting out certain lines of code) based on environmental cues.
  - zasdffaa 4y ago
    I'm aware of epigenetics via methylation
    - pazimzadeh 4y ago
      Well there's your mechanism. I don't understand "Why pick the former when the latter works." No one is picking anything, it's all happening simultaneously. An epigenetic solution would reduce selective pressure for a genetic solution, theoretically.
      - zasdffaa 4y ago
        Because the former mechanism, for lamarkism, wasn't given, and Some kind of "genetic intelligence" is just a vacuous proposition, so why raise it. Your mention of epigenetics was a sensible suggestion in that at least it's known to happen (although whether it can control skin colouring is another matter)

calibas 4y ago

If melanin protects against ionizing radiation, does that apply to humans as well? And does that mean darker-skinned human beings are better suited for space travel?

BurningFrog 4y ago
Yes, people have melanin in the skin to protect from damaging sunlight. Whiter skin evolved when humans migrated from Africa to regions with less sun, in order to get more vitamin D.
- tw20212021 4y ago
  So we all started black?
  - BurningFrog 4y ago
    I don't think we have any skin samples from back then, but yes, that is almost certainly the case.
  - saiya-jin 4y ago
    Not sure if you are joking, but that's by far the most probable option. Just look at civilizations living for millenia near equator, be it Africa, isolated islands in Indian ocean (ie Nicobar) or native Australians. Planet was colder, and around equator you actually have quite habitable places even now, deserts are further from equator. But you get tons of light whole year in very stable pattern.
  - samatman 4y ago
    What's started? We had fur at one point, and our still-furred cousins have pink skin, so our ancestors probably did as well. It's generally believed to be the case that dark skin evolved with hairlessness, and was lost by some branches of the tree during the glacial period.
    - sdflhasjd 4y ago

forgotmypw17 4y ago

https://archive.ph/JRvlJ https://archive.ph/JRvlJ

adolph 4y ago
Also https://onlinelibrary.wiley.com/doi/10.1111/eva.13476 https://onlinelibrary.wiley.com/doi/10.1111/eva.13476 No genetics were done. Measurements of a sample of 189 only.