Cannibalistic tadpoles and matricidal worms dispute evolution

  1. A recent study identifies phenotypic plasticity as the ability of tadpoles to change how they look and act, and how their tissues function, in response to their environment. If the pond also contains fairy shrimp, some tadpoles turn into aggressive carnivores and sometimes, the carnivorous tadpole stage becomes entrenched – without the need for a dietary trigger. This plasticity has also been confirmed in lizards, roundworms, and yeast. When yeast is exposed to the herbicide paraquat, the yeast copes by eliminating some or all of the DNA in their mitochondria, the cells’energy-producing organelles.
  1. Some consider this a classic example of “plasticity-first evolution”. On the surface, the findings vindicate Lamarck. The plasticity those changeable tadpoles display is built into their genetic code. And when an “acquired” trait does become “permanent”, it is because of mutations that “fixed” the plastic trait – a process biologists call genetic assimilation.
  2. Since plasticity is a built-in trait of so many organisms, it has obviously been mistaken for “evolution”. “Permanent” claim is meaningless given all organisms populations are ever-changing. The main questions are “what are the limits of plasticity?” and “what happens over the very long time?” The evidence to date is very clear:
    a. Plasticity is a built-in widespread if not universal characteristic of organisms
    b. It is limited in scope to a few traits like color, behavior, and metabolism
    c. Plasticity is reversible rather than cumulative
    d. It is not divergent as toads, lizards, roundworms, yeast, etc. never turn into not-toads, not-lizards, and so on.
  3. This is a repackaging of the same stories sold as proof of “evolution”. Darwin’s finches, the peppered moth, antibiotic resistant bacteria and, why not, the tanning humans. Too bad all these not only do not diverge into new organisms, but they all have been shown to revert eventually when the stimulus is removed. Finches change back their beaks depending on environment and never turn into non-finches, the black moths reversed to white and never to not-moths, antibiotic resistance disappears from the population when we reduce the use of antibiotics (see NIH recommendation), and neither light-skinned Nordics, nor dark-skinned Mediterraneans turn into not-humans under any circumstance.

https://www.sciencemag.org/news/2018/11/cannibalistic-tadpoles-and-matricidal-worms-point-powerful-new-helper-evolution

http://science.sciencemag.org/content/362/6418/988

https://www.nih.gov/news-events/nih-research-matters/reducing-antibiotic-prescriptions

172 Replies to “Cannibalistic tadpoles and matricidal worms dispute evolution”

  1. Nonlin.org
    Ignored
    says:

    Mung: I’m sure he has some suggested reading for you so that you don’t always come across as a complete novice.

    Do I sense some bitterness? You are doing your own research, but did you seek the mountain top guru? She’ll cure you of bitterness (and other things perhaps) 🙂

  2. Nonlin.org
    Ignored
    says:

    Allan Miller: You specifically stated that variation regresses to the mean.

    This is false. Read about ‘regression to the mean’.

  3. Allan Miller
    Ignored
    says:

    Nonlin.org: This is false. Read about ‘regression to the mean’.

    Reversion then. Variation ‘reverts’ to the mean. Still nonsense.

  4. Corneel Corneel
    Ignored
    says:

    Nonlin.org: So? Why “eye opener”? What has that to do with the question at hand:
    “where is the distinction between plasticity and “evolution”?

    Repeat: Differences due to phenotypic plasticity do not persist in a common environment, so cannot be responsible for species differences (as you suggested) nor for phenotypic variation with a proven genetic basis (such as industrial melanism in peppered moths).

    Nonlin.org: How would you know “(“Europeans”) will not revert to resemble the ancestral population”? Are the South Asians not dark? Are many Native American not darker that their supposedly Caucasian ancestors?

    Do Asians, Native Americans and Africans turn pale-skinned when they move to Europe? No, they don’t, because the difference in skin colour is genetic. In the absence of evolutionary mechanisms genetic variation persists

    Nonlin.org: There’s nothing racist about the “out of Africa” hypothesis.

    I was warning you that some people might read your comment as saying that modern Africans are primitive. Suit yourself, though.

    Nonlin.org: So you agree “Darwin has nothing to do with Mendel”?

    Did you read how Allan and T_aquaticus defined evolution? How can a genetic/heritable change NOT have anything to do with Mendel?

  5. Corneel Corneel
    Ignored
    says:

    Nonlin.org,

    To make this discussion somewhat more productive, would you mind answering a couple of questions? You have been talking about Mendelian inheritance and reversion (regression?) to the mean, and I wondered how you squared those concepts with your ideas.

    1) Mendel set up his experiments using stocks of pea plants that were true breeding for certain distinct traits (like wrinkled peas). How was he able to prevent these plants from “reverting to the mean”?

    2) You keep on saying that there is a reversion to the mean. The interesting thing is, if there is differential survival among the offspring related to a trait (say skin color), then you will have a NEW mean. Will the population revert to the new or the old mean? If the latter, what preserves this memory of the old mean?

  6. Nonlin.org
    Ignored
    says:

    Corneel: Repeat: Differences due to phenotypic plasticity do not persist in a common environment, so cannot be responsible for species differences (as you suggested) nor for phenotypic variation with a proven genetic basis (such as industrial melanism in peppered moths).

    That’s not at all clear. It’s like a bad translation from who knows what language.

    Do Asians, Native Americans and Africans turn pale-skinned when they move to Europe? No, they don’t, because the difference in skin colour is genetic. In the absence of evolutionary mechanisms genetic variation persists

    Are you serious? Are you saying that white Europeans are not descendants of black Africans? Maybe it takes more generations, but are we humans of all different colors and nuances not all members of the same family? Why make childish claims? What “evolutionary mechanisms”? It’s mere plasticity as sciencemag shows. Look at the examples given including lizards changing color.

    Did you read how Allan and T_aquaticus defined evolution? How can a genetic/heritable change NOT have anything to do with Mendel?

    Now everyone defines as they please? You got it exactly backwards: not Mendel but Darwin has nothing to do with “genetic/heritable change”. Look at Mendel’s laws / Punnett squares / Hardy-Weinberg equilibrium – there’s no room for Darwin’s nonsense.

  7. Nonlin.org
    Ignored
    says:

    Allan Miller: Reversion then. Variation ‘reverts’ to the mean.

    So you don’t understand anything you read? That’s embarrassing. For me too for carrying on with you.

  8. Nonlin.org
    Ignored
    says:

    Corneel: To make this discussion somewhat more productive, would you mind answering a couple of questions? You have been talking about Mendelian inheritance and reversion (regression?) to the mean, and I wondered how you squared those concepts with your ideas.

    1) Mendel set up his experiments using stocks of pea plants that were true breeding for certain distinct traits (like wrinkled peas). How was he able to prevent these plants from “reverting to the mean”?

    2) You keep on saying that there is a reversion to the mean. The interesting thing is, if there is differential survival among the offspring related to a trait (say skin color), then you will have a NEW mean. Will the population revert to the new or the old mean? If the latter, what preserves this memory of the old mean?

    This is where you go wrong big time: mean is not uniformity. The variability never dies as we see in the distinct traits (including wrinkled peas). But they’re all peas and we’re all humans. And unlike the Eugenists, we can’t say that the white man has evolved more than the African. And that’s exactly what this story of plasticity shows you: variability comes, persists and may or may not go, yet these variants do not represent “evolution”.

    If there were “differential survival” as in Darwin’s claim, we would not have all these variants, coexisting, right? The mean is more inclusive than superficial features like skin color, height, weight, etc. Think of humans – we’re all different, yet none of these traits make us less humans.

    And now try to mentally “evolve” an organism: a peacock with a bigger tail or a larger lion. Will they do well or will they have a harder time just like the peacock with a smaller tail and the smaller than normal lion? And if they manage to reproduce, would their progeny go even more extreme or would they be more like your average peacock or lion? You’re in luck because there is experimental evidence as to what happens.

  9. DNA_Jock
    Ignored
    says:

    Nonlin,
    You are not making any sense at all, I am sorry to say.
    You appear to be claiming that the differences in skin color between races are NOT genetic. I am embarrassed for you.
    You completely missed Corneel’s point re “true breeding” strains: when geneticists such as Mendel use that phrase, what do they mean by it, and why is it key to our conversation? Try to explain.

  10. Corneel Corneel
    Ignored
    says:

    Nonlin.org: Corneel: Repeat: Differences due to phenotypic plasticity do not persist in a common environment, […].

    That’s not at all clear.

    What isn’t clear about it? I am happy to explain.

    Nonlin.org: What “evolutionary mechanisms”? It’s mere plasticity as sciencemag shows. Look at the examples given including lizards changing color.

    Yes, let’s look at the lizards, shall we?

    In the 1980s, Claudia Luke, then a graduate student at UC Berkeley and now at Sonoma State University in Rohnert Park, California, switched dark and tan lizards between sandy and lava surfaces in the lab and found both varieties can adjust their colors to match their new surroundings in just a few weeks. But she also found the lizards from a sandy environment did not get as dark on lava as the regular lava dwellers, suggesting a genetic difference in the lizards’ ability to change color.

    So not mere plasiticity but also a genetic difference, agree? How did she find out? She observed persisting differences in a transplant experiment. See?

    Nonlin.org: Now everyone defines as they please?

    Hang on. My irony meter just exploded.

    Nonlin.org: You got it exactly backwards: not Mendel but Darwin has nothing to do with “genetic/heritable change”. Look at Mendel’s laws / Punnett squares / Hardy-Weinberg equilibrium – there’s no room for Darwin’s nonsense.

    Let’s consult the good ol’ wikipedia oracle about this:

    The seven assumptions underlying Hardy–Weinberg equilibrium are as follows:

    -organisms are diploid
    -only sexual reproduction occurs
    -generations are nonoverlapping
    -mating is random
    population size is infinitely large
    -allele frequencies are equal in the sexes
    -there is no migration, gene flow, admixture, mutation or selection

    [emphasis mine]

    Genetic drift, migration, mutation and selection are the four known evolutionary mechanisms. You are wrong.

  11. Corneel Corneel
    Ignored
    says:

    Nonlin.org: This is where you go wrong big time: mean is not uniformity. The variability never dies as we see in the distinct traits

    Thanks. This comment interests me. I am wondering how individuals in a population continuously revert to the mean whereas the variability never dies.

    Will you please explain this? I would like to hear more about this “mean”, because I do not understand what it is. Is it like an archetype or a blueprint? What does the “mean” pea plant look like? What does the “mean” human look like?

    You seem to be happy to accept variation in a species, but in your peacock/ lion example you argue that when some individuals move too far out they are pulled back to resemble the “average” peacock or the “average” lion. What are those boundaries? What is that average? Why do they exist?

    ETA: I am also curious about the “experimental evidence”, as it may help us find out what you are talking about. Can you present it?

  12. Nonlin.org
    Ignored
    says:

    DNA_Jock: You appear to be claiming that the differences in skin color between races are NOT genetic.

    That’s not my claim. You misread.

    You completely missed Corneel’s point re “true breeding” strains: when geneticists such as Mendel use that phrase, what do they mean by it, and why is it key to our conversation? Try to explain.

    Looked back and didn’t find the quote you mention. Care to go over that point again?

  13. Nonlin.org
    Ignored
    says:

    Corneel: Nonlin.org: Corneel: Repeat: Differences due to phenotypic plasticity do not persist in a common environment, […].

    1. That’s not at all clear.

    What isn’t clear about it? I am happy to explain.

    2. Nonlin.org: What “evolutionary mechanisms”? It’s mere plasticity as sciencemag shows. Look at the examples given including lizards changing color.

    Yes, let’s look at the lizards, shall we?

    In the 1980s, Claudia Luke, then a graduate student at UC Berkeley and now at Sonoma State University in Rohnert Park, California, switched dark and tan lizards between sandy and lava surfaces in the lab and found both varieties can adjust their colors to match their new surroundings in just a few weeks. But she also found the lizards from a sandy environment did not get as dark on lava as the regular lava dwellers, suggesting a genetic difference in the lizards’ ability to change color.

    So not mere plasiticity but also a genetic difference, agree? How did she find out? She observed persisting differences in a transplant experiment. See?

    3. Nonlin.org: Now everyone defines as they please?

    Hang on. My irony meter just exploded.

    4. Nonlin.org: You got it exactly backwards: not Mendel but Darwin has nothing to do with “genetic/heritable change”. Look at Mendel’s laws / Punnett squares / Hardy-Weinberg equilibrium – there’s no room for Darwin’s nonsense.

    Let’s consult the good ol’ wikipedia oracle about this:

    The seven assumptions underlying Hardy–Weinberg equilibrium are as follows:

    -organisms are diploid
    -only sexual reproduction occurs
    -generations are nonoverlapping
    -mating is random
    –population size is infinitely large
    -allele frequencies are equal in the sexes
    -there is no migration, gene flow, admixture, mutation or selection

    [emphasis mine]

    Genetic drift, migration, mutation and selection are the four known evolutionary mechanisms. You are wrong.

    1. Start with: What “differences”? What “common environment”? Better yet, rephrase the whole thing.
    2. Plasticity is not distinct from “genetic difference” – I already provided that quote from the article. To your quote: so what? Of course there’s “a genetic difference in the lizards’ ability to change color”. Same as in humans. Had they observed the lizzards long enough (many generations), they would have seen regression to the mean.
    3. ?
    4. Would we be having this argument if there was ONE confirmed “known evolutionary mechanism”? NO. So not “known”, but “fantasized”. Also, that particular research excludes “evolution” and that was the point, remember?

  14. Nonlin.org
    Ignored
    says:

    Corneel:
    1. Will you please explain this? I would like to hear more about this “mean”, because I do not understand what it is. Is it like an archetype or a blueprint? What does the “mean” pea plant look like? What does the “mean” human look like?

    2. You seem to be happy to accept variation in a species, but in your peacock/ lion example you argue that when some individuals move too far out they are pulled back to resemble the “average” peacock or the “average” lion. What are those boundaries? What is that average? Why do they exist?

    3. ETA: I am also curious about the “experimental evidence”, as it may help us find out what you are talking about. Can you present it?

    1. I am not reinventing the wheel here. Are you disputing ‘regression to the mean’ in biology? Ever heard of the normal distribution for whatever biological measure? Pea plant is farmed (to extremes), so not a good example. But there are all kind of stats for the average human. Is this news to you?!? Here’s a quick find study for you: https://www.sciencemag.org/news/2015/03/how-big-average-penis

    2. No hard boundaries. It’s like a spring – the more you stretch, the harder the pull back (or it just snaps). You can see that in domesticated plants and animals. Mutts are resilient while pure breeds have all kind of problems. Again: is any of this news to you? You seem to agree with my two examples. Then why the push back?

    3. It’s all around you. Have you ever heard that “2 tall parents will have shorter children”? Apparently Galton studied that first in 1886.

  15. Nonlin.org
    Ignored
    says:

    General comment: I notice the typical Darwinist reply to my:
    “the sky is blue” argument IS EITHER “are you really telling me the sky is blue? …prove it” OR “how can you claim the sky is brown? …you’re so wrong”. And let’s not forget the BEST: “Ha, ha, you said the sky is blue!”

  16. DNA_Jock
    Ignored
    says:

    Nonlin.org: Looked back and didn’t find the quote you mention. Care to go over that point again?

    Here..

    You are incoherent, and you keep repeatedly asserting things that are obviously wrong. I encourage you to take a course in biology.

    It is clear from nonlin’s most recent post that he IS talking about good old-fashioned statistical reversion to the mean.
    And he is correct that Darwin thought this was a problem, because he was unaware of Mendel’s work. Mendel’s observations on the particulate nature of inheritance solved Darwin’s apparent problem with regression.

    High School Biology. Yawn.

  17. DNA_Jock
    Ignored
    says:

    In repsonse to

    Do Asians, Native Americans and Africans turn pale-skinned when they move to Europe? No, they don’t, because the difference in skin colour is genetic.

    You wrote this:

    Nonlin.org: Are you serious? Are you saying that white Europeans are not descendants of black Africans? Maybe it takes more generations, but are we humans of all different colors and nuances not all members of the same family? Why make childish claims? What “evolutionary mechanisms”? It’s mere plasticity as sciencemag shows. Look at the examples given including lizards changing color.

    To me, that appears to be you claiming that the differences in skin color between races are NOT genetic, but rather “mere plasticity”.
    Please explain very carefully what you actually meant.

  18. Nonlin.org
    Ignored
    says:

    DNA_Jock: t is clear from nonlin’s most recent post that he IS talking about good old-fashioned statistical reversion to the mean.
    And he is correct that Darwin thought this was a problem, because he was unaware of Mendel’s work. Mendel’s observations on the particulate nature of inheritance solved Darwin’s apparent problem with regression.

    I already replied to Corneel’s: “You have been talking about Mendelian inheritance and reversion (regression?) to the mean, and I wondered how you squared those concepts with your ideas.”

    with

    “This is where you go wrong big time: mean is not uniformity. The variability never dies as we see in the distinct traits (including wrinkled peas). ”

    No, Mendel didn’t solve none of Darwin’s problems. Instead, he killed “gradualism” and showed inheritance stasis – see Hardy–Weinberg equilibrium.

    And of course, ‘statistical reversion to the mean’ as you prefer to call it is alive and well (at least you’re not disputing), and not something Mendel researched.

  19. Corneel Corneel
    Ignored
    says:

    Nonlin.org: Start with: What “differences”? What “common environment”? Better yet, rephrase the whole thing.

    With “differences” I mean phenotypic variation. For a continuous trait like height this can be expressed by the variance, a statistical measure of variation. Some of the phenotypic variance is caused by genetic differences (e.g. one of the traits investigated by Mendel was dwarf growth) and some of it by environmental factors (say, the amount of light a plant receives).

    A “common environment” is a location (like a garden or a lab) where variation in environmental influences (light, diet, etc) are minimized. Hence the phenotypic variation that persists between inbred / clonal stocks must be due to genetic factors. This is the insight we owe to Wilhelm Johannsen who made the phenotype-genotype distinction in the beginning of the previous century (yes, you are THAT far behind).

    Nonlin.org: No hard boundaries. It’s like a spring – the more you stretch, the harder the pull back (or it just snaps).

    Analogies are tricky business for this audience but here goes:
    What if I pull the spring on one side only? Won’t it just slide along? What tethers the metaphorical spring it to its place? I say nothing.

    Nonlin.org: It’s all around you. Have you ever heard that “2 tall parents will have shorter children”? Apparently Galton studied that first in 1886.

    Yes, sir Francis Galton, thought so. Let me inform you that some stuff has happended since. It was Galton’s student, Karl Pearson, who saw that this would not be an impediment to evolution. As I argued before, once the population mean changes, the values of the NEW offspring will regress to the NEW mean. The mean is not a solid mooring point, but merely a description of the population’s central tendency at this point in time.

  20. Corneel Corneel
    Ignored
    says:

    DNA_Jock: It is clear from nonlin’s most recent post that he IS talking about good old-fashioned statistical reversion to the mean.

    Galtons “regression to mediocrity” wielded as an argument against evolutionary theory in 2019. Gotta love this place.

  21. Alan Fox Alan Fox
    Ignored
    says:

    Corneel,

    Wikipedia on blending inheritance

  22. Mung Mung
    Ignored
    says:

    I aspire to regress to mediocrity.

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