[HN Gopher] Chernobyl black frogs reveal evolution in action
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Chernobyl black frogs reveal evolution in action
Author : gwbas1c
Score : 114 points
Date : 2022-09-30 15:15 UTC (7 hours ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| phtrivier wrote:
| I guess they'll get a couple of new ecosystems soon ? (Probably
| worth the downvotes. Should we still care ?)
| baron816 wrote:
| Still just two eyes though.
| layer8 wrote:
| I guess some Simpsons episodes will have to be revised.
| robocat wrote:
| 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 wrote:
| Almost sure it's only the skin. [But I can't find a good
| source.]
| _tom_ wrote:
| I dislike sites, like phys.org, that don't have a proper "opt
| out" from tracking.
|
| I encourage people to not visit them.
| bin_bash wrote:
| You might consider the fanboy annoyance list which blocks the
| cookie dialog: 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 wrote:
| 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 wrote:
| Note that you are not just accepting cookies, but _tracking_
| overall.
| ASalazarMX wrote:
| 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.
| daniel-cussen wrote:
| 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.
| KasianFranks wrote:
| "In addition, it opens the doors to promising applications in
| fields as diverse as nuclear waste management and space
| exploration."
| forgotmypw17 wrote:
| https://archive.ph/JRvlJ
| adolph wrote:
| Also
|
| https://onlinelibrary.wiley.com/doi/10.1111/eva.13476
|
| No genetics were done. Measurements of a sample of 189 only.
| aaron695 wrote:
| calibas wrote:
| 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 wrote:
| 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 wrote:
| So we all started black?
| saiya-jin wrote:
| 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.
| BurningFrog wrote:
| I don't think we have any skin samples from back then, but
| yes, that is almost certainly the case.
| samatman wrote:
| 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.
| vilhelm_s wrote:
| I think apes are generally black or brown under the fur,
| not pink. See e.g. https://www.reddit.com/r/pics/comments
| /bacdh/here_is_a_pic_o... https://twitter.com/gorillasdai
| ly/status/1417126388281266185...
| BurningFrog wrote:
| Googling "shaved chimpanzee" (did something new today!)
| gives photos in the pink/gray range.
|
| https://www.google.com/search?q=shaved+chimpanzee
| samatman wrote:
| And are our closest cousins, yes.
|
| Here's a popular-press citation for the consensus that
| our furred common ancestor was pink skinned:
| https://www.discovermagazine.com/planet-earth/why-did-
| darker...
| sitkack wrote:
| Space Is the Place!
| bell-cot wrote:
| The serious radiation hazards for astronauts are mostly from
| "harder" radiation, which penetrates deep into the human body.
|
| Vs.
|
| Human "color" is, at most, skin deep.
| skykooler wrote:
| Any radiation penetrating enough to get through an airtight
| wall or a spacesuit will be too penetrating to be appreciably
| blocked by melanin; it's mainly of use against lower-energy
| radiation.
| kragen wrote:
| Presumably it also applies to humans, but only a and b rays,
| not g-rays or cosmic rays. If a space suit or a spacecraft skin
| can't stop it, your skin isn't going to stop it either.
| OrvalWintermute wrote:
| 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.
| pazimzadeh wrote:
| No..
|
| It is a population that evolves, not an individual.
|
| Selection of a pre-existing feature that already occurs in the
| gene pool is exactly how evolution works. There are only two
| things needed for evolution: 1) generation of diversity between
| individuals (see sexual recombination, V(D)J recombination,
| etc) 2) selection of traits
|
| The fact that black frogs already existed at some frequency
| does not mean that the population did not evolve in response to
| radiation.
|
| But you are right that radiation is not the only thing that
| might select for dark frogs.
| roywiggins wrote:
| > it may be merely selection of a pre-existing color variant
| that already widely found in nature... very dark / black frogs
| which are already found in nature, may have just reproduced
| better
|
| If this variant is being selected for preferentially, that's
| evolution: "Typically, we think of biological evolution as
| changes in gene frequency within a population over time - if,
| say, birds with genes that produce wide beaks went from being
| rare to being common over multiple generations."
|
| https://evolution.berkeley.edu/evolution-101/mechanisms-the-...
| Osmium wrote:
| What is the distinction between adaptation and evolution here?
| melagonster wrote:
| If following text book, this is evolution, and adaptation is
| used when scientists finding some character actually is
| functional and evolved in past.
| UncleOxidant wrote:
| 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 wrote:
| 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...). 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 wrote:
| It seems to be a good argument for Lamarckism. Some kind of
| "genetic intelligence". I wonder how the probability weighs out.
| evtothedev wrote:
| This is exactly wrong. Lamarck believed in the inheritance of
| acquired traits (e.g. if you cut off a mouse's tail, then its
| babies would be born with shorter tails).
|
| Darwinism, conversely, is about selection from within a range
| of traits already present (i.e. beak size).
|
| These frogs come in a variety of colors. Dark colors have a
| better fitness for the highly radioactive environment. Those
| are the ones that reproduce. This is textbook Darwinian
| evolution.
| [deleted]
| [deleted]
| [deleted]
| zasdffaa wrote:
| Maybe. What mechanism though. Compare with evolution whose
| mechanism is mostly known and well understood. Why pick the
| former when the latter works.
| pazimzadeh wrote:
| 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 wrote:
| I'm aware of epigenetics via methylation
| pazimzadeh wrote:
| 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 wrote:
| 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)
| pazimzadeh wrote:
| I would think so.
| https://en.wikipedia.org/wiki/Epigenetics_and_melanoma
|
| Maybe the black frogs are at higher risk of melanoma.
| Nothing is ever free..
| zasdffaa wrote:
| Jaysus! Is there anything wikipedia doesn't have a
| detailed article on.
|
| (checks page history, nope it's been around a while, I
| guess you didn't just write it to win this one)
|
| Good catch anyway!
| yayitswei wrote:
| 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 wrote:
| and it happened in about 10 generations, which is zippy for
| evolution
| [deleted]
| josefresco wrote:
| > 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.
| Nzen wrote:
| Our perception may reflect the lack of surveillance and
| tracking of our entire environment. Marlene Zuk tracked [0]
| a trait's velocity in cricket populations of Hawaii that
| made them less able to attract mates, but also less likely
| to attract mites. That took 20 generations.
|
| [0] https://www.nature.com/articles/nature.2014.15323
| biomcgary wrote:
| Punctuated equilibrium
| (https://en.wikipedia.org/wiki/Punctuated_equilibrium) is
| an evolutionary hypothesis that evolution is very slow,
| except when selection pressures change. If true, the
| average speed of evolution (in this case, of phenotype) is
| slow, but highly bimodal (i.e., breakneck or near zero).
| 725686 wrote:
| Yes it generally is. Look at this fragment where Nick Lanes
| (British Biochemist) talks a little about this. If you
| don't know Nick Lane, his books are fantastic. I highly
| recommend Power, Sex and Suicide.
|
| https://youtu.be/tOtdJcco3YM?t=9927
| akiselev wrote:
| _> 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
| MonkeyMalarky wrote:
| 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 wrote:
| 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
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