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I broadly agree that this is disastrous in the same sense that any invasive species is. But I take exception to this silly paragraph: > He worries, for example

I broadly agree that this is disastrous in the same sense that any invasive species is. But I take exception to this silly paragraph: > He worries, for example, that the fluorescence-endowing genes from the escapees could end up being introduced in native fish with detrimental effects, perhaps making them more visible to predators. “It’s like a shot in the dark,” he says. This is no more likely than for other fish to get the same gene from the original jellyfish humans found it in. Unless there are close relatives of zebrafish in those streams which can cross-breed with the zebrafish, there is no chance of gene transfer. On the other hand, if they can interbreed, then its likely their offspring will inherit glowing gene. But that would be merely a symptom of a problem: that of an invasive species genetics diluting those of a native species.

dylan604 5y ago
I love when people try to sound smarter than they are when talking to reporters. This is about the only thing that makes local news interesting when people think they'll be famous for being on TV of a local newscast.
blacksmith_tb 5y ago
In fact it seems backwards, if the glowing gene makes fish with it more visible to predators, shouldn't that select against it and make it less likely to gain a foothold in the environment? I would think local, camouflaged fish would benefit if their usual predators switched to the easier meal.
- freemint 5y ago
  Except glowing fishes might have mating advantage and it it probably also a dominant gene. We don't know and that should give us room for pause.
  - hadlock 5y ago
    But before that, they need to survive until sexual maturity, which is well north of one year for most fish. They're not like mice which can reproduce inside of a month or three.
    - _Microft 5y ago
      Wikipedia says that zebrafish have a generation time of 3 month and the article says that the glowing ones reproduce even earlier. https://en.wikipedia.org/wiki/Zebrafish#Reproduction https://en.wikipedia.org/wiki/Zebrafish#Reproduction
  - NicoJuicy 5y ago
    You can't mate or produce offspring if you're eaten.
    - freemint 5y ago
      The fact that we found them says they are probably not gonna be eaten to extinction
- jagger27 5y ago
  > Unlike Florida, the Brazilian creeks don’t have any local predators for zebrafish, and Magalhães believes they are now thriving.
_0ffh 5y ago
Right, also if glowing is in fact detrimental to the fitness of these native fish it will not spread in the population, even if it gets introduced. That would be diametrically opposed to how evolution works.
- heavyset_go 5y ago
  I can imagine a scenario where a glowing trait results in higher rates of reproduction because of sexual selection, resulting in large populations with the trait, even if the trait might increase mortality rates. Especially so if selection against the trait stems from something like learned behavior of predators. Evolution doesn't mean that "bad" genes can't spread.
  - MengerSponge 5y ago
    https://www.pnas.org/content/102/21/7618 https://www.pnas.org/content/102/21/7618 Thank you for reminding me of my favorite evo bio article of all time. In this particular species, females preferentially mate with the largest penis they can find, which applies strong selective pressure to hang dong. Unfortunately they're fish, so it's harder to swim if they're packing heat, making them more likely to get eaten by predators.
inphusorian 5y ago
You forgot horizontal gene transfer.
- tiagod 5y ago
  I think there's only one documented instance of horizontal gene transfer in fish and it increased fitness dramatically - https://www.quantamagazine.org/dna-jumps-between-animal-species-no-one-knows-how-often-20210609/ https://www.quantamagazine.org/dna-jumps-between-animal-spec...
- ch4s3 5y ago
  This is very rare in eucaryotes, and especially in larger and more complex animals. Eucaryotes work really hard to keep foreign DNA out and their own DNA in the nucleus. Here’s a good article about the only known case in fish and why it’s so unlikely[1]. [1] https://www.cell.com/trends/genetics/fulltext/S0168-9525(21)00051-2 https://www.cell.com/trends/genetics/fulltext/S0168-9525(21)...
cultofmetatron 5y ago
how tragic. if only there was some sort of natural selection mechanism to prevent maladaptive phenotypes from spreading in a population.
hinkley 5y ago
So it's successful enough for the gene to spread to the whole population, but the whole population dies because the gene makes them easier to eat? Yeah I don't buy it either. That can be a problem with endangered species and loss vigor, for instance by allowing garden flowers to cross with their wild neighbors, leading to increased numbers in the short term, but a population crash during the next drought, flood, or killing frost, because the garden variety is used to being coddled. But something that makes them glow? That's going to be selected for or against every single day.
gwbas1c 5y ago
> On the other hand, if they can interbreed, then its likely their offspring will inherit glowing gene Many domesticated species will revert back to their wild genes, or revert very closely. For example, when goldfish go ferrel they end up looking mostly like wild carp, except for some minor differences. But goldfish aren't genetically engineered. They are deliberately inbred to to preserve recessive colors and patterns. I think the big question is, what happens when glowing fish go ferrel? Are the glowing genes dominant? Are there non-glowing genes in the population?
- ImaCake 5y ago
  I think it's incorrect to say they "revert to their wild genes". It's more a change in their outer appearance and traits while their genetics remains largely untouched (at least over only a few generations). Revert also implies the scaling back of features, but evolution is blind and there is no such thing as "better", merely things that do better in the environment as it is right now. The glowing gene will be GFP which is a gene from jellyfish which has been introduced into these fish. So if any mutation suppresses or "turns off" the GFP gene, and GFP is maladative, then those fish will quickly outbreed their glowing siblings. The weird thing here, is the GFP gene will probably still be in their genome, it will just have a couple of errors that completely break it. I haven't heard of the goldfish example so I can't comment much on that. Except to say that I wonder if the "reversion" is because goldfish are inter-breeding with wild carp? Maybe not, and it is a mix of strong selection pressure and epigenetics causing the phenotypic change.
  - NicoJuicy 5y ago
    I think he's correct. We had a small showcase of this behavior in the pawn of my parents. The goldfish color disappeared within 2 generations, probably some breeding with others too => partially red fish within 1 generation
murphyslab 5y ago
> This is no more likely than for other fish to get the same gene from the original jellyfish humans found it in. Unless there are close relatives of zebrafish in those streams which can cross-breed with the zebrafish, there is no chance of gene transfer. I'm not sure that we know that yet. The science on horizontal gene transfer is in its nascent stages. Only last year did scientists first supply solid evidence of animal-to-animal horizontal gene transfer: > [...] herrings and smelts, two groups of fish that commonly roam the northernmost reaches of the Atlantic and Pacific Oceans, both make [antifreezing proteins]. But it is very surprising, even weird, that both fish do so with the same AFP gene — particularly since their ancestors diverged more than 250 million years ago and the gene is absent from all the other fish species related to them. > A March paper in Trends in Genetics holds the unorthodox explanation: The gene became part of the smelt genome through a direct horizontal transfer from a herring. It wasn’t through hybridization, because herring and smelt can’t crossbreed, as many failed attempts have shown. The herring gene made its way into the smelt genome outside the normal sexual channels. [0] https://www.quantamagazine.org/dna-jumps-between-animal-species-no-one-knows-how-often-20210609/ https://www.quantamagazine.org/dna-jumps-between-animal-spec... The original article notes that the leading mechanistic hypothesis for this crossover involves genetic material hitching a ride during spawning: > The remarkable gain of this advantageous gene was postulated to have occurred via HGT from foreign DNA attaching to sperm during spawning [2.], in a manner analogous to the technique of sperm-mediated gene transfer employed in laboratories to transfer genes to organisms, including fish [9.]. [1] https://doi.org/10.1016/j.tig.2021.02.006 https://doi.org/10.1016/j.tig.2021.02.006 One might fairly extrapolate that the conditions necessary for such an unusual genetic exchange may be far more feasible for species in close proximity, rather than from a species of jellyfish limited to the west coast of North America. [2] https://www.inaturalist.org/taxa/325995-Aequorea-victoria https://www.inaturalist.org/taxa/325995-Aequorea-victoria It still seems extremely unlikely, however we lack a good sense of not only the frequency of such events (presumably quite low), but also the total number which have occurred over evolutionary history.
- ImaCake 5y ago
  So I agree with you in broad strokes but I want to nit-pick some meanings here. >It still seems extremely unlikely, however we lack a good sense of not only the frequency of such events (presumably quite low), but also the total number which have occurred over evolutionary history. I think we have plentiful evidence for horizontal gene transfer, especially in bacteria (see "F-plasmids"). More relevant is all the endogenous retroviral sequences buried in our own DNA, all of which are effectively horizontal gene transfer between viruses and our ancestors. We know quite a bit about these random chunks of DNA so I am hesitant to call HGT either nascent or unlikely. Between seeing all the viral DNA and knowing roughly how fast mutations erase it, we can probably get a good estimate of how frequently it occurs. But, I totally agree that this is all very unlikely. At least, HGT events are rare on human timescales. But they do seem to be somewhat common on evolutionary timescales! Sometimes I wish I could see our biosphere in 1000 years time. It would be a radically weird place.
neurocat123 5y ago
This seems silly for another reason: these fish are genetically engineered to be fluorescent, which means that if you shine light on them at one frequency (typically UV-A light), they emit light at another frequency (red, green or blue). They are not luminescent, which is the spontaneous emission of light, like in fireflies. Lacking any UV light in the wild of nature, surely, they would hardly look any different from any ordinary fish.

dylan604 5y ago

I love when people try to sound smarter than they are when talking to reporters. This is about the only thing that makes local news interesting when people think they'll be famous for being on TV of a local newscast.

blacksmith_tb 5y ago

In fact it seems backwards, if the glowing gene makes fish with it more visible to predators, shouldn't that select against it and make it less likely to gain a foothold in the environment? I would think local, camouflaged fish would benefit if their usual predators switched to the easier meal.

freemint 5y ago
Except glowing fishes might have mating advantage and it it probably also a dominant gene. We don't know and that should give us room for pause.
- hadlock 5y ago
  But before that, they need to survive until sexual maturity, which is well north of one year for most fish. They're not like mice which can reproduce inside of a month or three.
  - _Microft 5y ago
    Wikipedia says that zebrafish have a generation time of 3 month and the article says that the glowing ones reproduce even earlier. https://en.wikipedia.org/wiki/Zebrafish#Reproduction https://en.wikipedia.org/wiki/Zebrafish#Reproduction
- NicoJuicy 5y ago
  You can't mate or produce offspring if you're eaten.
  - freemint 5y ago
    The fact that we found them says they are probably not gonna be eaten to extinction
jagger27 5y ago
> Unlike Florida, the Brazilian creeks don’t have any local predators for zebrafish, and Magalhães believes they are now thriving.

_0ffh 5y ago

Right, also if glowing is in fact detrimental to the fitness of these native fish it will not spread in the population, even if it gets introduced. That would be diametrically opposed to how evolution works.

heavyset_go 5y ago
I can imagine a scenario where a glowing trait results in higher rates of reproduction because of sexual selection, resulting in large populations with the trait, even if the trait might increase mortality rates. Especially so if selection against the trait stems from something like learned behavior of predators. Evolution doesn't mean that "bad" genes can't spread.
- MengerSponge 5y ago
  https://www.pnas.org/content/102/21/7618 https://www.pnas.org/content/102/21/7618 Thank you for reminding me of my favorite evo bio article of all time. In this particular species, females preferentially mate with the largest penis they can find, which applies strong selective pressure to hang dong. Unfortunately they're fish, so it's harder to swim if they're packing heat, making them more likely to get eaten by predators.

inphusorian 5y ago

You forgot horizontal gene transfer.

tiagod 5y ago
I think there's only one documented instance of horizontal gene transfer in fish and it increased fitness dramatically - https://www.quantamagazine.org/dna-jumps-between-animal-species-no-one-knows-how-often-20210609/ https://www.quantamagazine.org/dna-jumps-between-animal-spec...
ch4s3 5y ago
This is very rare in eucaryotes, and especially in larger and more complex animals. Eucaryotes work really hard to keep foreign DNA out and their own DNA in the nucleus. Here’s a good article about the only known case in fish and why it’s so unlikely[1]. [1] https://www.cell.com/trends/genetics/fulltext/S0168-9525(21)00051-2 https://www.cell.com/trends/genetics/fulltext/S0168-9525(21)...

cultofmetatron 5y ago

how tragic. if only there was some sort of natural selection mechanism to prevent maladaptive phenotypes from spreading in a population.

hinkley 5y ago

So it's successful enough for the gene to spread to the whole population, but the whole population dies because the gene makes them easier to eat? Yeah I don't buy it either. That can be a problem with endangered species and loss vigor, for instance by allowing garden flowers to cross with their wild neighbors, leading to increased numbers in the short term, but a population crash during the next drought, flood, or killing frost, because the garden variety is used to being coddled. But something that makes them glow? That's going to be selected for or against every single day.

gwbas1c 5y ago

> On the other hand, if they can interbreed, then its likely their offspring will inherit glowing gene Many domesticated species will revert back to their wild genes, or revert very closely. For example, when goldfish go ferrel they end up looking mostly like wild carp, except for some minor differences. But goldfish aren't genetically engineered. They are deliberately inbred to to preserve recessive colors and patterns. I think the big question is, what happens when glowing fish go ferrel? Are the glowing genes dominant? Are there non-glowing genes in the population?

ImaCake 5y ago
I think it's incorrect to say they "revert to their wild genes". It's more a change in their outer appearance and traits while their genetics remains largely untouched (at least over only a few generations). Revert also implies the scaling back of features, but evolution is blind and there is no such thing as "better", merely things that do better in the environment as it is right now. The glowing gene will be GFP which is a gene from jellyfish which has been introduced into these fish. So if any mutation suppresses or "turns off" the GFP gene, and GFP is maladative, then those fish will quickly outbreed their glowing siblings. The weird thing here, is the GFP gene will probably still be in their genome, it will just have a couple of errors that completely break it. I haven't heard of the goldfish example so I can't comment much on that. Except to say that I wonder if the "reversion" is because goldfish are inter-breeding with wild carp? Maybe not, and it is a mix of strong selection pressure and epigenetics causing the phenotypic change.
- NicoJuicy 5y ago
  I think he's correct. We had a small showcase of this behavior in the pawn of my parents. The goldfish color disappeared within 2 generations, probably some breeding with others too => partially red fish within 1 generation

murphyslab 5y ago

> This is no more likely than for other fish to get the same gene from the original jellyfish humans found it in. Unless there are close relatives of zebrafish in those streams which can cross-breed with the zebrafish, there is no chance of gene transfer. I'm not sure that we know that yet. The science on horizontal gene transfer is in its nascent stages. Only last year did scientists first supply solid evidence of animal-to-animal horizontal gene transfer: > [...] herrings and smelts, two groups of fish that commonly roam the northernmost reaches of the Atlantic and Pacific Oceans, both make [antifreezing proteins]. But it is very surprising, even weird, that both fish do so with the same AFP gene — particularly since their ancestors diverged more than 250 million years ago and the gene is absent from all the other fish species related to them. > A March paper in Trends in Genetics holds the unorthodox explanation: The gene became part of the smelt genome through a direct horizontal transfer from a herring. It wasn’t through hybridization, because herring and smelt can’t crossbreed, as many failed attempts have shown. The herring gene made its way into the smelt genome outside the normal sexual channels. [0] https://www.quantamagazine.org/dna-jumps-between-animal-species-no-one-knows-how-often-20210609/ https://www.quantamagazine.org/dna-jumps-between-animal-spec... The original article notes that the leading mechanistic hypothesis for this crossover involves genetic material hitching a ride during spawning: > The remarkable gain of this advantageous gene was postulated to have occurred via HGT from foreign DNA attaching to sperm during spawning [2.], in a manner analogous to the technique of sperm-mediated gene transfer employed in laboratories to transfer genes to organisms, including fish [9.]. [1] https://doi.org/10.1016/j.tig.2021.02.006 https://doi.org/10.1016/j.tig.2021.02.006 One might fairly extrapolate that the conditions necessary for such an unusual genetic exchange may be far more feasible for species in close proximity, rather than from a species of jellyfish limited to the west coast of North America. [2] https://www.inaturalist.org/taxa/325995-Aequorea-victoria https://www.inaturalist.org/taxa/325995-Aequorea-victoria It still seems extremely unlikely, however we lack a good sense of not only the frequency of such events (presumably quite low), but also the total number which have occurred over evolutionary history.

ImaCake 5y ago
So I agree with you in broad strokes but I want to nit-pick some meanings here. >It still seems extremely unlikely, however we lack a good sense of not only the frequency of such events (presumably quite low), but also the total number which have occurred over evolutionary history. I think we have plentiful evidence for horizontal gene transfer, especially in bacteria (see "F-plasmids"). More relevant is all the endogenous retroviral sequences buried in our own DNA, all of which are effectively horizontal gene transfer between viruses and our ancestors. We know quite a bit about these random chunks of DNA so I am hesitant to call HGT either nascent or unlikely. Between seeing all the viral DNA and knowing roughly how fast mutations erase it, we can probably get a good estimate of how frequently it occurs. But, I totally agree that this is all very unlikely. At least, HGT events are rare on human timescales. But they do seem to be somewhat common on evolutionary timescales! Sometimes I wish I could see our biosphere in 1000 years time. It would be a radically weird place.

neurocat123 5y ago

This seems silly for another reason: these fish are genetically engineered to be fluorescent, which means that if you shine light on them at one frequency (typically UV-A light), they emit light at another frequency (red, green or blue). They are not luminescent, which is the spontaneous emission of light, like in fireflies. Lacking any UV light in the wild of nature, surely, they would hardly look any different from any ordinary fish.