5 ms·

At last, some recognition that evolution is not just random trial and error.

JPLeRouzic 6y ago
I would read the article as if the transfer was a a random event, : But how the whitefly managed to swipe a plant gene is unclear. One possibility, says Turlings, is that a virus served as an intermediate, shuttling genetic material from a plant into the whitefly genome.
- ironmagma 6y ago
  Right, but there’s a difference between random events causing biological changes vs. random mutations having to happen during reproduction/birth and proved out in the form of natural selection.
  - flobosg 6y ago
    Not sure what you meant with that. This gene transfer event is a mutation and as such is also being subject to natural selection.
  - yes_man 6y ago
    From evolutionary point of view it is semantical why genome changed. Also I’ve never heard of any biology textbook or journal claiming mutations would only happen during reproduction or birth. Mutations happen all the time, that’s one reason we have diseases like cancer. Your reproductive cells can mutate any time throughout your life passing out differences to offspring. There is also genetic recombination bringing out traits that didn’t exist, or suppressing ones that do.
    - andrewflnr 6y ago
      Only mutations in sperm or egg can be passed on, so those are mainly the ones relevant to evolution.
    - ironmagma 6y ago
      It's hardly semantics. Many people over the past few hundred years have found it mind-bogglingly unlikely that organisms can evolve to be so purpose-built to survive in their environments if the only input driving that forward is the circumstances of their birth and the sheer number of organisms being produced. This study suggests that's not the only way these genetic changes happen, which makes the premise of evolution much less unlikely.
      - flobosg 6y ago
        The structural mutation described in the study likely happened as “circumstances of their birth”: a gene insertion in the germline genome. > This study suggests that's not the only way these genetic changes happen The study says nothing about the transfer mechanism, only that it took place.
      - webmaven 6y ago
        > It's hardly semantics. Many people over the past few hundred years have found it mind-bogglingly unlikely that organisms can evolve to be so purpose-built to survive in their environments if the only input driving that forward is the circumstances of their birth and the sheer number of organisms being produced. That's really just a failure of imagination. Also, it ignores that the mechanisms of evolution have themselves evolved. Sure, evolution seems unlikely if you assume discrete genes have to change in lockstep to adjust traits successfully (eg. if you assume that separate changes are needed to adjust bones, muscles, skin, nerves, etc. to lengthen a limb), but that isn't how our bodies wirk (if it was, it would be nearly impossible to heal from an injury), nor is it how genes control that development. Instead, you have genes that control things in less direct ways, such as body to limb ratio, and other genes that direct development of things like muscles in relation to bones and joints don't have to change at the same time for everything to keep working. Even that's an overly simplified model, but you should get the general idea. You might like to read the book "The Plausibility of Life", which goes into more detail.
  - gpvos 6y ago
    The mutation is as random as any other kind, it's just a different mechanism.
    - ironmagma 6y ago
      Hence why I never said it wasn't random, specifically that it's not the random trial and error of genetic mutations at birth.
  - shakow 6y ago
    > there’s a difference between random events causing biological changes vs. random mutations having to happen during reproduction/birth From an evolutionary perspective, there are none. Both are but sources of variation (the actual cause does not matter) in the genome; which, depending on their impact, may or may not get fixated by natural selection.
echelon 6y ago
How is this not random? The viral genes we have in our genome were acquired by chance. This was a fluke that got amplified.
- lolthishuman 6y ago
  Because it’s selected for, at least recursively based on entity specific attractors. In this case bacteria, another case mating preference.
  - echelon 6y ago
    After the first few generations of the gene, sure. But the first organism to get it probably got it somatically and transferred it through gametes. Evolution is hill climbing, but the gene introduction was random. Just as mutations themselves are.
    - lolthishuman 6y ago
      I don’t think it’s purely random like what random actually means. It’s a set (or graph if you wish) with bias. All biology has a bias.
ralusek 6y ago
Not sure why you're being downvoted, I understand you perfectly well. To clarify for others: random gene mutation within an organism is not the same a random gene introduction from external source. Take something like an Orchid Praying Mantis. If it were discovered that the Orchid Praying Mantis got some of its coloring from a gene transfer of orchid plants with which it cohabitated, that would remove an enormous amount of random mutations that needed to have occurred within its own genome to achieve that goal. Nobody is saying that the mantis wouldn't be subject to all of the same forces of natural selection thereafter, or that the particular gene that was transferred wasn't itself a random selection from the orchid. It just makes the arrival at certain gene configurations immeasurably more likely than they would've been within the same time period, given an organism's lineage had only had its own random mutations available.
- tum92 6y ago
  HGT is fascinating & important, but it’s also completely accepted, recognized, and studied. Horizontal gene transfer was actually discovered before we had any consensus that DNA was the biological mechanism of heredity, and the experiments showing evidence of HGT were used as evidence for that claim.
dqpb 6y ago
Even if you look only at random genetic mutations, these are being inserted into an incomprehensibly large dynamical system with its own selective pressures. It’s a distributed computation at such a massive scale, you would never have any hope of fully stimulating or predicting its outcome. So I’m not sure what you mean by “just random trial and error”.
- ironmagma 6y ago
  We don’t really have a good definition of random to start, but we can say things are more or less random than other things. When people say evolution is entirely due to “random mutations,” I would argue that’s misleading, because it’s less random than arbitrary bit flips. If an entire chunk of a gene from an already-evolved organism can enter at any time, that in my opinion is less random than the bit flips hypothesis. And sure, people in this thread can say this is old science, but my point is around the popular understanding of evolution and how it is communicated to students and the general public. It’s less random than total randomness, and many people completely deny it.
tomrod 6y ago
Can't be trial and error. There is no guide. Thus there is no trial. There is simply natural events or circumstance incidentally causing the death of individuals in environments for which they are unsuited before reproduction.
- ironmagma 6y ago
  Trial is defined as "a test of the performance, qualities, or suitability of someone or something." An organism's life is definitely a test of its ability to survive; a flower seed being buried in a shady spot is thus a trial. There is no need for a guide.
  - tomrod 6y ago
    No one is testing, however. Folks commonly use verbiage derived from intellectual design, and we should be conscientious on the subject. There is a system in the randomness, but we need not attribute will to the system.
    - ironmagma 6y ago
      There need not be a tester for a test to exist. The organism tests itself in some sense. The system (universe) tests the organism, the same way things can stand the “test of time.” Whether you personally interpret this as intelligent design is entirely outside of the discussion.

I would read the article as if the transfer was a a random event, : But how the whitefly managed to swipe a plant gene is unclear. One possibility, says Turlings, is that a virus served as an intermediate, shuttling genetic material from a plant into the whitefly genome.

ironmagma 6y ago
Right, but there’s a difference between random events causing biological changes vs. random mutations having to happen during reproduction/birth and proved out in the form of natural selection.
- flobosg 6y ago
  Not sure what you meant with that. This gene transfer event is a mutation and as such is also being subject to natural selection.
- yes_man 6y ago
  From evolutionary point of view it is semantical why genome changed. Also I’ve never heard of any biology textbook or journal claiming mutations would only happen during reproduction or birth. Mutations happen all the time, that’s one reason we have diseases like cancer. Your reproductive cells can mutate any time throughout your life passing out differences to offspring. There is also genetic recombination bringing out traits that didn’t exist, or suppressing ones that do.
  - andrewflnr 6y ago
    Only mutations in sperm or egg can be passed on, so those are mainly the ones relevant to evolution.
  - ironmagma 6y ago
    It's hardly semantics. Many people over the past few hundred years have found it mind-bogglingly unlikely that organisms can evolve to be so purpose-built to survive in their environments if the only input driving that forward is the circumstances of their birth and the sheer number of organisms being produced. This study suggests that's not the only way these genetic changes happen, which makes the premise of evolution much less unlikely.
    - flobosg 6y ago
      The structural mutation described in the study likely happened as “circumstances of their birth”: a gene insertion in the germline genome. > This study suggests that's not the only way these genetic changes happen The study says nothing about the transfer mechanism, only that it took place.
    - webmaven 6y ago
      > It's hardly semantics. Many people over the past few hundred years have found it mind-bogglingly unlikely that organisms can evolve to be so purpose-built to survive in their environments if the only input driving that forward is the circumstances of their birth and the sheer number of organisms being produced. That's really just a failure of imagination. Also, it ignores that the mechanisms of evolution have themselves evolved. Sure, evolution seems unlikely if you assume discrete genes have to change in lockstep to adjust traits successfully (eg. if you assume that separate changes are needed to adjust bones, muscles, skin, nerves, etc. to lengthen a limb), but that isn't how our bodies wirk (if it was, it would be nearly impossible to heal from an injury), nor is it how genes control that development. Instead, you have genes that control things in less direct ways, such as body to limb ratio, and other genes that direct development of things like muscles in relation to bones and joints don't have to change at the same time for everything to keep working. Even that's an overly simplified model, but you should get the general idea. You might like to read the book "The Plausibility of Life", which goes into more detail.
- gpvos 6y ago
  The mutation is as random as any other kind, it's just a different mechanism.
  - ironmagma 6y ago
    Hence why I never said it wasn't random, specifically that it's not the random trial and error of genetic mutations at birth.
- shakow 6y ago
  > there’s a difference between random events causing biological changes vs. random mutations having to happen during reproduction/birth From an evolutionary perspective, there are none. Both are but sources of variation (the actual cause does not matter) in the genome; which, depending on their impact, may or may not get fixated by natural selection.

echelon 6y ago

How is this not random? The viral genes we have in our genome were acquired by chance. This was a fluke that got amplified.

lolthishuman 6y ago
Because it’s selected for, at least recursively based on entity specific attractors. In this case bacteria, another case mating preference.
- echelon 6y ago
  After the first few generations of the gene, sure. But the first organism to get it probably got it somatically and transferred it through gametes. Evolution is hill climbing, but the gene introduction was random. Just as mutations themselves are.
  - lolthishuman 6y ago
    I don’t think it’s purely random like what random actually means. It’s a set (or graph if you wish) with bias. All biology has a bias.

ralusek 6y ago

Not sure why you're being downvoted, I understand you perfectly well. To clarify for others: random gene mutation within an organism is not the same a random gene introduction from external source. Take something like an Orchid Praying Mantis. If it were discovered that the Orchid Praying Mantis got some of its coloring from a gene transfer of orchid plants with which it cohabitated, that would remove an enormous amount of random mutations that needed to have occurred within its own genome to achieve that goal. Nobody is saying that the mantis wouldn't be subject to all of the same forces of natural selection thereafter, or that the particular gene that was transferred wasn't itself a random selection from the orchid. It just makes the arrival at certain gene configurations immeasurably more likely than they would've been within the same time period, given an organism's lineage had only had its own random mutations available.

tum92 6y ago
HGT is fascinating & important, but it’s also completely accepted, recognized, and studied. Horizontal gene transfer was actually discovered before we had any consensus that DNA was the biological mechanism of heredity, and the experiments showing evidence of HGT were used as evidence for that claim.

dqpb 6y ago

Even if you look only at random genetic mutations, these are being inserted into an incomprehensibly large dynamical system with its own selective pressures. It’s a distributed computation at such a massive scale, you would never have any hope of fully stimulating or predicting its outcome. So I’m not sure what you mean by “just random trial and error”.

ironmagma 6y ago
We don’t really have a good definition of random to start, but we can say things are more or less random than other things. When people say evolution is entirely due to “random mutations,” I would argue that’s misleading, because it’s less random than arbitrary bit flips. If an entire chunk of a gene from an already-evolved organism can enter at any time, that in my opinion is less random than the bit flips hypothesis. And sure, people in this thread can say this is old science, but my point is around the popular understanding of evolution and how it is communicated to students and the general public. It’s less random than total randomness, and many people completely deny it.

tomrod 6y ago

Can't be trial and error. There is no guide. Thus there is no trial. There is simply natural events or circumstance incidentally causing the death of individuals in environments for which they are unsuited before reproduction.

ironmagma 6y ago
Trial is defined as "a test of the performance, qualities, or suitability of someone or something." An organism's life is definitely a test of its ability to survive; a flower seed being buried in a shady spot is thus a trial. There is no need for a guide.
- tomrod 6y ago
  No one is testing, however. Folks commonly use verbiage derived from intellectual design, and we should be conscientious on the subject. There is a system in the randomness, but we need not attribute will to the system.
  - ironmagma 6y ago
    There need not be a tester for a test to exist. The organism tests itself in some sense. The system (universe) tests the organism, the same way things can stand the “test of time.” Whether you personally interpret this as intelligent design is entirely outside of the discussion.