3 ms·

It's a meaningful distinction because adaptation has the potential to introduce novel mechanisms while plasticity doesn't. So if you mistook one for the other,

It's a meaningful distinction because adaptation has the potential to introduce novel mechanisms while plasticity doesn't. So if you mistook one for the other, you might assume that a given crop will continue to adapt to a warming climate when what's actually happening is that it's approaching the bounds of its plasticity and yet another degree of warming will cause it to fail. You could also make bad assumptions related to rates. One might assume that adaptation will occur within some time window when actually they're extrapolating based on plasticity. Sure, plasticity and its limits are themselves the result of natural selection, but there are still experiments you can do to distinguish the two (e.g. does the change show up in the genome versus the transcriptome or the proteome?). I guess I'm just uncertain about how useful it is to split hairs beyond a certain point. Like, you could say that everything is caused by the big bang, case closed, but that's not going to affect any subsequent decisions that people might make.

taeric 9mo ago
Fair that I think it is valuable to know some things are stronger adaptations than others. I just don't see the point in claiming it is not, itself, an adaptation. Feels very "not actually evolution" in claim. It is, but there are obvious limits to what it can achieve. As an easy example, to your point, would you say that adaptation and evolution lead to land creatures? There are obvious limits to how quickly and how well that could have possibly worked. But it also feels safe to say that some organisms almost certainly had a level of plasticity that made it more likely for them to survive the process?
- __MatrixMan__ 9mo ago
  Re: your questions, yes and yes. If its both plasticity and adaptation at play in all cases then there's not much sense drawing a line, such as the evolution of land creatures. And its also probably silly to worry about adaptation without plasticity. But it does make sense in the plasticity without adaptation case. For instance there are people born in Tibet with adaptations for altitude, and people born in the Andes with adaptations for lead tolerance. And if those of us without those adaptations were to try to tolerate such heights, and such concentrations of lead, we wouldn't do as well because we lack the genes for that particular adaptation. Even though we are partially adapted to those things in general. The "X is not a result of adaptation" predicate makes sense in relation to other things that are more directly a result of adaptation.
  - taeric 9mo ago
    But doesn't this just go to my point that you would more expect further adaptations from those that already have the plasticity? Fair that you could get them in either, but the point of evolution/adaptation is that often the mechanism is not a first class one. To the peppered moth example, it isn't like there was a specific mutation that caused them to change color. Both colors always existed. The prevalence at the population level was essentially the result of external drivers to the species. So, in plants, it is fair to say that those with more plasticity are able to change when they flower in response to environmental changes. Why is it not fair to expect that those most able of doing that are the ones you are likely to see further adaptations on to keep adjusting? Yes, we can see individual mechanisms and we can focus on them. Such that we don't have to hope for random mutations that further advantage things. But, adaptation and evolution are not defined as only random mutations. (Or have they been somewhat redefined into that?) I think more cleanly stated for my point, I am not arguing against the idea of plasticity. I am arguing that adaptation is not defined as only random mutations introducing novel characteristics. Specifically because the fundamental example for evolution that used to be taught was definitively not a novel characteristic of the species.
    - __MatrixMan__ 9mo ago
      I was also taught that evolution is primarily driven by changes in allele frequently within a population far more often than by the emergence of new alleles via mutation. > Why is it not fair to expect that those most able of doing that are the ones you are likely to see further adaptations on to keep adjusting Its a reasonable hypothesis, what kind of experiment would confirm it? Would you be comparing between species or between offspring of distinct individuals? I think you'd need to focus on sexual reproduction for both your experimental and control variables, since you're looking to reason about the rate of adaptation. I'm going to read the guy's paper and report back, but from the title I'm thinking that he's finding that asexually propagated plants show just as much flowering-time change in the presence of temperature changes as those whose parents were pollinated and concluding that this code is quite flexible, but that any rewrites among the sexually propagated set are not related to flowering time change. That would be my approach anyway. So my point is just that those are different results. It would be interesting (though perhaps a bit Lamarckian) if evolution favored the more plastic when granting adaptations towards still greater plasticity. But that's a totally separate conclusion from one that studies a phenomenon which changes even when genes do not.

taeric 9mo ago

Fair that I think it is valuable to know some things are stronger adaptations than others. I just don't see the point in claiming it is not, itself, an adaptation. Feels very "not actually evolution" in claim. It is, but there are obvious limits to what it can achieve. As an easy example, to your point, would you say that adaptation and evolution lead to land creatures? There are obvious limits to how quickly and how well that could have possibly worked. But it also feels safe to say that some organisms almost certainly had a level of plasticity that made it more likely for them to survive the process?

__MatrixMan__ 9mo ago
Re: your questions, yes and yes. If its both plasticity and adaptation at play in all cases then there's not much sense drawing a line, such as the evolution of land creatures. And its also probably silly to worry about adaptation without plasticity. But it does make sense in the plasticity without adaptation case. For instance there are people born in Tibet with adaptations for altitude, and people born in the Andes with adaptations for lead tolerance. And if those of us without those adaptations were to try to tolerate such heights, and such concentrations of lead, we wouldn't do as well because we lack the genes for that particular adaptation. Even though we are partially adapted to those things in general. The "X is not a result of adaptation" predicate makes sense in relation to other things that are more directly a result of adaptation.
- taeric 9mo ago
  But doesn't this just go to my point that you would more expect further adaptations from those that already have the plasticity? Fair that you could get them in either, but the point of evolution/adaptation is that often the mechanism is not a first class one. To the peppered moth example, it isn't like there was a specific mutation that caused them to change color. Both colors always existed. The prevalence at the population level was essentially the result of external drivers to the species. So, in plants, it is fair to say that those with more plasticity are able to change when they flower in response to environmental changes. Why is it not fair to expect that those most able of doing that are the ones you are likely to see further adaptations on to keep adjusting? Yes, we can see individual mechanisms and we can focus on them. Such that we don't have to hope for random mutations that further advantage things. But, adaptation and evolution are not defined as only random mutations. (Or have they been somewhat redefined into that?) I think more cleanly stated for my point, I am not arguing against the idea of plasticity. I am arguing that adaptation is not defined as only random mutations introducing novel characteristics. Specifically because the fundamental example for evolution that used to be taught was definitively not a novel characteristic of the species.
  - __MatrixMan__ 9mo ago
    I was also taught that evolution is primarily driven by changes in allele frequently within a population far more often than by the emergence of new alleles via mutation. > Why is it not fair to expect that those most able of doing that are the ones you are likely to see further adaptations on to keep adjusting Its a reasonable hypothesis, what kind of experiment would confirm it? Would you be comparing between species or between offspring of distinct individuals? I think you'd need to focus on sexual reproduction for both your experimental and control variables, since you're looking to reason about the rate of adaptation. I'm going to read the guy's paper and report back, but from the title I'm thinking that he's finding that asexually propagated plants show just as much flowering-time change in the presence of temperature changes as those whose parents were pollinated and concluding that this code is quite flexible, but that any rewrites among the sexually propagated set are not related to flowering time change. That would be my approach anyway. So my point is just that those are different results. It would be interesting (though perhaps a bit Lamarckian) if evolution favored the more plastic when granting adaptations towards still greater plasticity. But that's a totally separate conclusion from one that studies a phenomenon which changes even when genes do not.