- 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.
- 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.
- 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. - 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.nih.gov/news-events/nih-research-matters/reducing-antibiotic-prescriptions
Not ‘a gene’; that’s a bit simplistic. But how on earth else do you think these things happen, if not through genetics? What’s the root cause of instinctive behaviour in your world?
I can remember when I was in high school wondering this, and just kind of figured, well, we must know the answer to this somehow. I was so surprised to find out we have no clue.
I also was recently talking to a friend of mine who is a very strong looking guy, extremely muscular. I asked him if he was a gymnast before, because he was built just like one. He said, no actually, but its funny you should say that, because he said both his parents AND his grandfather were gymnasts. He had never done any gymnastics before though. Then he showed me a video of his 83 year old grandfather doing the human flag gymnast move.
Not a gene, but what ?
phoodoo,
There’s no question heritable innate behaviours must be in the genome. There’s not much other than DNA in a sperm cell. How and where are still largely unanswered questions.
Lamarck.
Mechanism?
Genetics, like I said. Collections of genes.
You appear to have the odd idea that the only things genetics controls are shape and colour, and that organisms just kind of plop out, then sniff out something on the ether and start … ‘behaving’.
Numerous lines of evidence point to behaviour being significantly under genetic control, even among organisms that do a lot of learning. And there is clearly a potential for a survival advantage. The instinct to suckle, to take just one example.
Can we include plants here? Where is ‘the gene’ that tells roots to grow down and stalks up, or leaves to fall off and dormant buds to set? Is that different? Why?
Quantum physics 😀
For no reason at all, the word “auxin” shot into my head from sixty years absence!
Phenotypic plasticity is yet another genetic trait that evolution can act on. That’s how it helps evolution.
Evolution begins with changes in DNA sequence. Plasticity ends at the same place. You don’t need to change DNA sequences to get plasticity, but you do need to change DNA sequence for evolution to occur.
Really? What about the whites and the blacks and the rest of us? And again, seems you did not read or understand the sciencemag article.
Now you are just being silly. You know what tanning is, I am sure. Tanned parents do not have tanned offspring.
I understand it just fine. I also have the great advantage over you that I understand genetics, and its relevance to evolution, which helps in interpreting and evaluating the various claims made. You seem quite doggedly determined not to understand the subject you presume to critique.
What are you talking about?
From the article:
How do you even separate plasticity from genetics? What does it even mean “genetically uniform lines”? “Uniform” how?
I ask for an example and reply with opinions? What’s wrong with you?
What does “readily” mean? If humans turn European from Africans in time, is it not normal to expect the reverse to take about as long? But here’s one thing they haven’t done and will never do: turn into “mutants” as per Holyweird… although some people make me wonder…
You wish.
1. “Modern synthesis” never was anything other than Darwinism hitchhiking the real science of Genetics out of its well deserved obscurity. But Mendel’s genetics demolished Darwin’s “gradualism” and is the anti-Darwin and true, testable science unlike Darwinism. Therefore, the shotgun marriage between Mendel and Darwin known as “Modern Synthesis” never made any sense. Blending inheritance in which offspring were thought to be the genetic intermediates of their two parents is the gradualism imagined by Darwin, but blending inheritance would result in the rapid end of genetic variation within a population contrary to biologic observations. Once demonstrated false, biologic gradualism should have been dropped altogether and without this pillar, Darwinism would have crumbled like the sandcastle it is.
It’s called inductive reasoning. Of course it’s subject to falsification with one single counterexample. But you don’t have any, do you?
A heritable change ALWAYS occurs in the genome. And in fact you can’t even talk about ‘change’ in sexual reproduction – go read about it.
You’re not making any sense again, but you do make up stories.
Did I say you’re not making any sense? Read the sciencemag article again and see how it doesn’t fit anything you claim.
I bet you think that hair growth is an example of phenotypic plasticity.
And where exactly do you draw the line between tanning and race? Presumably the Amerindians descend from Asians rather than Africans, yet many are being born “tanned”. Go see for yourself.
See the replies to Corneel above:
a) There is not connection in either direction from genetics to “evolution”
b) That passage show you do not understand “just fine”
One thing I can highly recommend when dealing with press releases or opinion articles is to always go back to the primary source: the original publication. Here is one of the parts showing that there is preciously little fieldwork involved:
Apparently, this is an eye-opener for you, but this is the way this kind of experiment needs to be set up: by raising tadpoles under controlled conditions in a common environment. You can see that two distinct treatments were being used to test for plasticity. The effect of genetic variation was controlled by using established laboratory stocks. If the model species can tolerate it (for example many plants) the stocks are often inbred or clonally derived for even higher uniformity. That is how one separates plasticity from genetics.
No, caucasian people (“Europeans”) will not revert to resemble the ancestral population of African origin* for many reasons. But in the context of this discussion it is important to stress that caucasians have, at many genetic loci, only a subset of alleles that Africans have. That is, caucasians have lost a lot of genetic variation that they can’t get back.
*I need to warn you that your suggestion that Africans are sporting the primitive condition may be taken to be borderline racist by some. Best to avoid these statements in the future.
Yes, I distinctly remember that was in the same year that Liechtenstein sent out its army of robot soldiers and achieved world domination.
Meanwhile in the real world: Quantitative Genetics and its treatment of polygenic continuous traits is the thing you should read up on.
Sure. How does that address the point though?
Of course you can. Sexual reproduction is indeed a bit of a specialism of mine.
A heritable change occurs in the genome, but you can’t talk about such change in sexual species? That is all manner of confused.
So you think it impossible that any allele could be lost from any population, because you have some populations that alleles have not been lost from? You think there is not a single example of a lost allele in the entirety of biological history? Even in species whose population is reduced in a bottleneck to a handful? That’s hilarious. Where do they keep them all?
There is a distinction between the tanning that occurs as a result of solar exposure and that due to natural melanin levels. If you don’t even know this, I don’t you why you think you are fit to discuss genetics.
Saying it’s so don’t make it so. If evolution has no connection to inheritance, I am mystified as to what you think either phenomenon is.
This is proving quite the exercise in watching someone exhibit cocksure cluelessness. Yes, I know you think it’s me.
I realise now I misread the reference to tanning – more like the rather condescending way people of my father’s generation (though not my father***) would refer to ‘our brown friends’, and not a Lamarckian reference to inheritance of actual tanning at all.
*** in an incident that’s stuck with me, my dad took a visiting African fire chief to our local pub. “Your friend’s got a suntan” said one wag. My dad was furious.
🙂
I’m sure he has some suggested reading for you so that you don’t always come across as a complete novice.
So? Why “eye opener”? What has that to do with the question at hand:
“where is the distinction between plasticity and “evolution”?
Are you saying sciencemag is wrong? That “evolutionary biologists” have no idea what they do? Stop being so slippery and admit plasticity is damning evidence against “evolution”.
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?
* Stop being a pussy. There’s nothing racist about the “out of Africa” hypothesis.
So you agree “Darwin has nothing to do with Mendel”? That was easy 🙂
Real simple. The descendant’s DNA is always different than the parent’s (change) in asexual reproduction. You can’t talk about “change” when you have a ‘mix’ in sexual reproduction.
Your:
“Evolution begins when a heritable change occurs in the genome. You know what a genome is, I presume.”
makes no sense in asexual reproduction (trivial) or sexual reproduction (mix, not “change”)
You are just wrong. Mendel’s work was on peas, a sexual species. The vast majority of genetic work has been on sexual species, because that is what interests us most. – us, our food, our pets, many of our pests, all sexual.
The idea that sexual species cannot change at the genetic level is unadulterated bullshit.
Nonlin.org,
How can something simultaneously make no sense and be trivial?
Mendel did away with blending inheritance. Alleles remain discrete, ‘particulate’. You have much to learn, grasshopper.
I was looking for a counterexample. Still waiting… No? Then induction stands.
And of course, this is not about one particular “allele” (be careful: “allele”, “gene” are going obsolete). It is about “reversion to the mean” (TRUE) versus “divergence of character” (FALSE). But you knew this, only you’re reluctant to admit.
Nah. Even as a simple thought experiment: if all but two of a species were killed, then that species has lost almost all its prior variation. There are only 4 instances of each locus. Therefore alleles – thousands of ’em – must have been lost, from the ancestrally larger population. (Will no-one think of the alleles?).
Your inductive assumption that no alleles have been lost, ever, would be contradicted by the fact that species have gone extinct. At some point prior to going extinct, there must have been just two of them. At that point, almost all variants in the ancestral population have shuffled off this mortal coil. They are ex-alleles. So it would be ludicrous to demand direct proof when simple logic suffices in this case.
Therefore your ‘induction’, to remain standing, requires that no species ever recovered from a drop in population size – from getting small enough to lose alleles, they must go on to extinction. May I offer you an inductive counterargument to that supposition…?
I’ll admit that you are talking shite, if that helps.
An artificial distinction. First exposure (tanning), then (and concurrent) genetic changes. Sciencemag has pictures if it helps you. Look for: “The (adjustable) color of lizards”
That’s exactly the difference (chasm) between Darwin’s fantasy and Mendel’s scientific findings. Look at the Mendelian Inheritance Tables – they specifically tell you “probabilistic traits conservation”, meaning “NO EVOLUTION!”
Of course, one can demonstrate that this is false directly. If you pick members of a variant collection at random, copy them and put them back, you dont get ‘regression to the mean’, you get loss of variants, one by one, till only one variant remains. Happens every time; a well-known phenomenon of random sampling. I don’t know what would protect biological populations from this rule. Loss of variation is a massive problem in domesticated lines, and threatened species.
But never happens, according to Nonlin.
Not artificial at all. Tanning is a triggered response, directly caused by solar radiation. Skin colour at birth is not (hint: we aren’t lzards).
They tell me goobledegook meaning ALL CAPS? Your ability to formulate a coherent argument appears to be waning. From a low start point.
Who cares about alleles?
Your erroneous assumption is that organisms are just a sum of alleles, and that once lost, these alleles cannot be recovered. I already provided links to prove the DNA is overrated, hence also the genes and alleles.
Can you point out where I promised you “no extinction”? Totally ridiculous.
So you are not prepared to accept the truth:
“reversion to the mean” (true) versus “divergence of character” (false).
That’s totally fine. You will one day!
What do you mean “copy them and put them back”? Are you talking about a controlled experiment where you, the Designer decide what happens by controlling the environment? That’s simply farming/agriculture. But even that won’t allow you to turn dogs into cat-bears-unicorns.
In the context of this discussion: both of us. That is, you insisted that they are never lost. Now, you don’t care. Hey ho.
However overrated they may be, they are still lost, contrary to your earlier notions. There is very little likelihood that they will come back in exactly the same state they were, bit for bit. And try taking the DNA out of an organism and see how overrated it is.
You insist that, unless I demonstrate directly a loss of alleles, then they ‘regress to the mean’. Which I can only interpret as an assertion that alleles never go extinct.
Nope. I’m too far gone in the ways of truth to swallow unsubstantiated horseshit I’m afraid. It is a raw fact that alleles must be lost, because each generation is a sample of the one before. Your ‘mean’ is a fantasy.
I see you’re going in circles. There’s no point explaining you for the n-th time.
I’m talking about any situation where replication is random. That doesn’t have to be farming – any population will do. Which is why it’s a problem for conservation. This thing that doesn’t happen.
Please yourself, but you are simply denying genetic facts. You can declare that the colour of Africans is exactly the same as me turning lobster red then brown, but it really isn’t the same genes. You’re just asserting they are the same in ignorance.
Go back and read. You latched on to “alleles” which is not something I even brought up. And now you falsely attribute to me claims never made. This “discussion” is not going anywhere.
Go calm down and, IF you have something intelligent to add, we can continue at that point.
You specifically stated that variation regresses to the mean. The fact that you chose not to use the term ‘allele’ does not change the fact that it is indeed ‘alleles’ of which you speak.
What is it then that you think ‘regresses to the mean’ and is never lost?
Nonlin.org,
Haha! It would help enormously if you had a clue about genetics.