Back in the late 1980's, I read Molecular Evolutionary Genetics by Masatoshi Nei. He introduced me to the concept that the history of life is driven by mutation and that the old-fashioned view of mutationism needs to be looked at more carefully. A decade later, Arlin Stoltzfus took up the cause and he has published a number of papers on the topic.If you want to read more about mutationism then you can't find a better source than the series of posts by Arlin on Sandwalk from 2010. The last one, The Mutationism Myth VI: Back to the Future, contains links to all of the others. Be warned, it will be hard to resist the idea of mutationism after you read Arlin's explanation. It will hurt your brain.
I just learned that Masatoshi Nei is about to publish a new book called Mutation-Driven Evolution. Here's the description on Amazon ...
Theme
Mutation
The purpose of this book is to present a new mechanistic theory of mutation-driven evolution based on recent advances in genomics and evolutionary developmental biology. The theory asserts, perhaps somewhat controversially, that the driving force behind evolution is mutation, with natural selection being of only secondary importance. The word 'mutation' is used to describe any kind of change in DNA such as nucleotide substitution, gene duplication/deletion, chromosomal change, and genome duplication. A brief history of the principal evolutionary theories (Darwinism, mutationism, neo-Darwinism, and neo-mutationism) that preceded the theory of mutation-driven evolution is also presented in the context of the last 150 years of research. However, the core of the book is concerned with recent studies of genomics and the molecular basis of phenotypic evolution, and their relevance to mutation-driven evolution. In contrast to neo-Darwinism, mutation-driven evolution is capable of explaining real examples of evolution such as the evolution of olfactory receptors, sex-determination in animals, and the general scheme of hybrid sterility. In this sense the theory proposed is more realistic than its predecessors, and gives a more logical explanation of various evolutionary events.I can't wait to get my hands on a copy of this book. Look for a review in a few months.
Mutation-Driven Evolution is suitable for graduate level students as well as professional researchers (both empiricists and theoreticians) in the fields of molecular evolution and population genetics. It assumes that the readers are acquainted with basic knowledge of genetics and molecular biology.
118 comments :
The theory asserts, perhaps somewhat controversially, that the driving force behind evolution is mutation, with natural selection being of only secondary importance.
That sounds right to me.
Why polarizing the field by coining the term Mutationism and saying that NS is only of secondary importance? isn't it enough to acknowledge the better understanding that we now have about the role of mutation in evolution? I are now more aware about the importance of mutation in driving evolution in relation to the other population-genetic forces.
Me too.
What drives Evolution? - Quantum Mechanics:
"on the microscopic level there exists a further source of still more radical uncertainty, embedded in the quantum structure of matter. A mutation is in itself a microscopic event, a quantum event, to which the principle of uncertainty consequently applies. An event which is hence and by its very nature essentially unpredictable."
Jacques Monod - Chance and Necessity (1970)
Why are you equating "a quantum event" (a discrete event, which a genetic mutation surely is) with quantum mechanics?
*We
Larry, Are you removing my posts? If yes. Why?
The uncertainty principle of quantum mechanics does not apply in any way to mutations. To even begin to make such a claim, one would need to state which two quantities related to mutations cannot be known simultaneously. One can only conclude that Monod was not referring to the uncertainty principle of quantum mechanics, or that he misunderstood it.
Well it looks like another book Larry is going to criticize. Why? He thinks he is the ultimate authority among the THEORISTS OF EVOLUTION. I’ m kind of glad actually that Larry is my neighbor-his lawn is shit though. Well, Larry obviously somehow figured out that early mutations of an embryo that disrupt body plan formation are deleterious. Well you gotta "drift now" hihihi
I am just agreeing with Monod. He is referring to an event "to which the principle of uncertainty consequently applies." What he is he is referring to is the quantum mechanical uncertainty which applies at the molecular level. DNA by the way is a molecule if you didn't know. He of course was aware that Schrödinger had already discussed this with regard to demonstrating the molecular level of mutations caused by X-rays in his seminal book "What is Life". A book which inspired Watson and Crick in their work on DNA structure and its genetic implications.
Too many biologists don't realize we are all made of quantum stuff and consequently they don't realize there is no classical world but only a quasi-classical world which is emergent from a quantum mechanical foundation. This ignorance has been made worse by QM woo pedlars like Deepak Chopra at one end and distinguished physicists like Penrose producing wild theories about quantum consciousness at the other, which has discouraged biologists from taking quantum biology seriously.
This has been partially remedied by work over the past couple of years on the QM optimization of the photosysnthetic mechanism.
Larry, could you give a short summary of how mutationalism differs from the nearly neutral theory? Does the term represent a world view substantially different from that of Kimura?
The nearly neutral theory has to do with the fixation of neutral or nearly neutral mutations by genetic drift. This relies heavily on effective population sizes. The modern mutation theory, on the other hand, emphasizes the directional pressure that mutation propensities or biases impose on the course of evolution. Mutation biases can heavily influence the outcome of a selection regime on a gene, for example.
Konrad you don't understand QM and the uncertainty principle.
As a starting point for seeing how mutations are quantum mechanical Schrödinger considered X-rays as photons which are subject to the uncertainty principle and cause mutations which we can be demonstrated to be at the molecular level. He writes when discussing genetic inheritance:
"In this case it is supplied by quantum theory. In
the light of present knowledge, the mechanism of
heredity is closely related to, nay, founded on,
the very basis of quantum theory."
Erwin Schrödinger "What is Life" Dublin, 1944
An approach to how molecular quantum superpositions occurring in DNA bases can cause SNP's was proposed by Löwdin back in the sixties (Per-Olov Löwdin. Rev. Mod. Phys. 35, 724, 1963).
There is a recent review of the Lowdin mechanism (Kryachko, E. S. (2002), The origin of spontaneous point mutations in DNA via Löwdin mechanism of proton tunneling in DNA base pairs: Cure with covalent base pairing. Int. J. Quantum Chem., 90: 910–923.)
For a recent accessible video discussing quantum biology try this talk by Jim Al-Khalili at the Royal Institution.
http://www.youtube.com/watch?v=wwgQVZju1ZM
This appears remarkably silly. Of course mutations are the "driving" force in evolution in the most literal sense because without them there would be nothing for selection to work on. Still plant leaves would not be flat and vertebrates would not have bones without selection.
You could just as well say that because engines are the driving force behind your car making its way to Montreal the steering wheel is of secondary importance. Point is, you would drive but you would not arrive at a useful destination.
I'm not deleting your comments, ... yet.
I might reconsider if you continue to insult me like you do in the comment right below this one. This is your first warning.
Analogy: Imagine directing the steering wheel in direction A (i.e., selection), while the engine is somehow directing the car towards B (i.e., mutation). At the end you get to C, a point intermediate between A and B. That is what happens when mutation rates are high and biased, in contrast to its traditional assumed role as merely raw material (it is not usually understood as a driving force at all--a pressure).
Not a different world view at all then. It's not as if Kimura was unaware of mutation biases.
From Jim Al-Kalili's video:
". . . and it is, still, a very speculative area of research."
Couldn't agree more, Jim.
Sergio
I don't understand.
By what mechanism do germ-line mutations acquire an evolutionary "direction"? Is there any means by which mutations alone can arrive at a solution to some environmental challenge, except by pure accident? Which is after all what "random with respect to fitness" actually means.
Sergio,
That sounds as if you think that mutations act as a teleological force. I am reasonably sure that is not the case.
Also, can you perhaps explain into what "direction" the mutations causing haemophilia, von Gierke's disease, Cori's disease or Tay–Sachs disease are "driving" the human population?
Volume of nucleotide ~= 3 x 10**9 m**3
Volume of electron ~= 3 x 10**30 m**3
Difference? 21 orders of magnitude (and even more for more fundamental particles).
Any effects of physical quantum indeterminacy inside nucleotides would be swamped by the ordinary chemical interactions between the nucleotide and its surroundings.
Fascinating video - thanks for linking it. He discusses hypothesized instances of quantum entanglement, quantum superposition and quantum tunneling in biological systems - the last being a potential mechanism for mutations in DNA, proposed by Lowdin. No mention of the uncertainty principle, but I take it Monod was using the term in a broad sense referring essentially to all of QM.
It's still a stretch to claim that quantum mechanics drives mutation - it is plausible that a QM mechanism such as tunneling drives _some_ mutations, but rather less plausible that it is the primary mechanism. The most obvious mechanism causing mutations is replication error, which does not seem to be in need of a non-classical explanation.
I think Sergio is just talking about mutation bias - things like CpG hypermutation. Nothing that one would ordinarily call a driving force.
If I understand this, an example:
Sometime in the Precambrian when arthropods had less differentiated segments a mutation or series of mutations occurred in a population that changed the coordination of the anterior hox genes. This mutation would have had no phenotype at the time but it would have led to that population evolving into chelicerates and spiders with their cephalothorax while an almost indistinguishable population without the mutation would have given rise the crustaceans and insects. This mutation need not have happened, the odds were one in a million, and if it hadn't spiders would have never existed. Many alternate mutations could have happened but didn't - any of which would have led to lineages that don't now exist. But this mutation didn't 'direct' the evolution of spiders, it just changed the context that all subsequent mutations occur making the evolution of something spider-like much more likely. Stoltfuz doenst like the term but I'd say it 'constrained' subsequent evolution. It seems to me obvious that this is part of the picture but I don't know why it has to be at odds with the MS. I think both mechanisms are likely
It seems to me this Correction to how evolution might of worked is because their is a uneasy thought that mutations and selection on them doesn't work. So it must be the glory of mutations doing most of the work without selection being so important.
In short the great changes evolution tries to explain is not seemly true by just selection on happanchance mutation. More mutationism please.
That the glory of biology so needs errors in the biology to bring the glory hints it never happened this way. Its like a grand myth being believed in and trying to overthrow the original idea of God and genesis.
I'll await the book, and I have no other clues about Nei's views on this. Perhaps he's had some recent publications on the subject that I've missed. But is this anything more than the old argument about evolutionary canalization, i.e. that some mutations are more likely than others, or that certain rare mutations can greatly alter the selective landscape?
Thanks for the comments. Tim the electron is a fundamental particle and therefore according to the Standard Model it is a point particle and has no volume.
I agree with Andy Albrecht there is no such thing as classical probabilities.
"In our view the things we call “classical probabilities” can be seen as originating in the quantum probabilities that govern the microscopic world, suitably propagated by physical processes so as to be relevant on classical scales."
Andreas Albrecht and Daniel Phillips, arXiv:1212.0953
On this basis all stochastic processes' origins are quantum mechanical. Which makes even the wobble mechanism quantum mechanical.
Al of the tautomerism based QM models of point mutation from Watson and Crick's though Löwdin's and others onwards produce quantum superpositions following proton quantum tunneling and the question is whether the lifetime of of the superposition before decoherence is greater than the time for a base pair to replicate.
By the way in Chance and Necessity, Monod was referring to the original Watson and Crick tautomerism model (1953 Cold Spring Harbor Symposia on Quantitative Biology 18: 123-131)
By the way an interesting review discussing these topics from the basis of the philosophy of science is David N. Stamos (Quantum Indeterminism and Evolutionary Biology, Philosophy of Science, Vol. 68, No. 2 (Jun., 2001), pp. 164-184)
"Laurence A. MoranSaturday, June 01, 2013 8:20:00 PM
I'm not deleting your comments, ... yet.
I might reconsider if you continue to insult me like you do in the comment right below this one. This is your first warning."
Fair enough Larry. The joke with your lawn was a bluff as You may already know, because you may as well not have a lawn as a lot of people live in high-rise buildings Mississipi. Anyway, thanks for the warning. U R Cool Larry.
PS. Please don't ban me because I insult your beliefs. Okay? If you do, kindly let me know why BEFORE YOU DO THAT. IS THAT FAIR?
I'm used to the fact that anti-evolution is based entirely on ad hominem attacks and quote mines. But "his lawn is shit" is an ad hominem I haven't seen before.
WHAT WOULD YOU DO IF YOU WERE THE CREATIONIST?
LET'S JUST THINK FOR A MOMENT. WOULD RESURRECTING OF THE DEAD MEAN ANYTHING TO THE OBSERVERS? FOR SOME REASON, I DON'T THINK SO.......
If there was proof for the REAL MACRO-EVOLUTION-I mean properly defined and proven, would we be having this discussion today?
If there was proof for the REAL MACRO-EVOLUTION-I mean properly defined and proven, would we be having this discussion today?
Since there is abundant evidence for macroevolution as properly defined by biologists, and we are having this discussion today, I would say the answer to your question is "Yes".
Really? Abundant evidence according to whom or what? Your beliefs? Well, I don't mind blind faith if it is faith and not science that claims to be based on evidence and I mean not evolutionary manipulation but the real deal. Dream on asshole. You have no evidence because there is no such one. If there were,it would be in our face. So, you have to spit, and lie and call names all those that don't buy your shitty evidence so that you can feel comfortable in your shitty beliefs that in the end have to account for one thing-the origin. Dream on you shitty, stupid fuck.
That supposes two things: (1) that this specific mutation was very unlikely to happen, and (2) that there is precisely one mutation that can make any important evolutionary innovation possible.
I'd doubt both of these assumptions. AFAIK, gene duplications happen all the time. Sometimes they set the stage for subsequent diversification in function, often the copies are merely turned off and become pseudogenes. The point is, it is highly likely that if it had not happened in the one population you are envisioning (or if that population had been killed off by a random event) the same thing would have happened in another related population 500,000 years later.
And for many other adaptations there are different ways of achieving the same outcome. That is the lesson of convergent evolution, after all. If somethings is very useful it will evolve, given enough time. Just look at all the apparently independently evolved eyes.
Bob Cherkavsky,
Seriously, look at what you just wrote. You charge Nullifidian with "name calling" and "spitting" after he calmly answered your question without any name-calling whatsoever, and in the same breath you throw out a string of very offensive insults yourself. That is not the behaviour of a civilized, mature and self-aware individual.
And yes, of course the evidence is staring us in the face. As a writer once joked, "Chuck Norris - does not believe in evolution, despite access to mirrors."
In my opinion, misplacing your shift key ought to be sufficient cause for banning. Posting incoherent nonsense is another. Both at once? Priceless.
To put it as simply as possible, the main evidence for macroevolution is the same as the evidence for common descent. If two species that are clearly related by descent have very different characteristics, and if the gain of very different characteristics is what you mean by macroevolution, then macroevolution must have happened.
So what's the evidence for common descent? Literally, billions of pieces: bases and other characters in the genomes of the species involved. There's other evidence too, but that's the bulk of it, and that's enough for now.
The ratio of migration rate to mutation rate controls the degree of differentiation between demes at equilibrium in island models, contrary to the beliefs of many geneticists. I guess that could be considered an example of mutation-driven evolution?
Lou Jost
1 and 2 just add complications ( and I'm aware of them) I just posed this to see if I understand 'mutationism' correctly.
Consider a species that has stabilizing selection on body size x. So x is the ideal body size taking into consideration metabolism, mate competition, defense from predators, attractiveness to predators, effectiveness at getting prey etc etc. If by luck several 'large alleles' appear in the population that would create a selective advantage for doing 1 of 2 things: either get smaller to size x or get much larger to a new size that maximizes all of the above. This would be determined by the relative selection coefficients, the number of mutations that could achieve either, vs the likelihood of each. The same could occur for 'small alleles' .............So...whether a particular population evolves into a much larger species over time (eohippus to horses?) or a much smaller species is completely due to luck- whether small alleles or big alleles appear in the population ( vs likelihood etc etc of course)
I'm asking..is this mutationism?? If so I cant really picture what a competing theory such as MS would claim. ( its all environment?? )
RodW
Nobel laureate Muller already in the 1930s proved experimentally that mutations can be caused by cosmic rays, and that a single quantum event was sufficient to cause a mutation. (He showed this by doing the kind of intensity/event rate analysis that Einstein did for the photoelectric effect, which established the quantum nature of light.) If you do the calculations to figure out the quantum uncertainty in direction and time-of-arrival of cosmic rays, you find that the distance between nucleotide bases is comparable to the uncertainty in the cosmic ray's trajectory. So yes, at least some mutations are non-deterministic quantum events.
Lou Jost
I guess it is important to re-emphasize that mutations are the basis of evolution because in the wake of ENCODE re-defining the meaning of function some researchers claim a mutation free form of evolution solely based on transcriptome differences between individuals:
"Our data set reveals the extent of transcript isoform diversity in the yeast genome at unprecedented resolution. Since most yeast genes have fewer than one mRNA molecule per cell, the sheer number of isoforms detected here, even within a single environmental condition, indicates that every cell in a clonal population has a unique transcriptome in terms of RNA abundance, sequence and thus regulatory potential. Such cell-to-cell heterogeneity may confer evolutionary advantages, enabling more rapid adaptation of the species to unforeseen environmental challenges." (Pelechano V, Wei W, Steinmetz LM. (2013): Extensive transcriptional heterogeneity revealed by isoform profiling. Nature. 2013 Apr 24. doi: 10.1038/nature12121
They actually worked with a yeast strain. Thus, if their assumptions were true how trustworthy would any published data gained with yeast strains, bacteria clones or mammalian cell line be?
Dream on asshole.
So, you have to spit, and lie and call names all those that don't buy your shitty evidence so that you can feel comfortable in your shitty beliefs that in the end have to account for one thing-the origin.
Dream on you shitty, stupid fuck.
This is performance art, right?
29+ Evidences for Macroevolution
I'm obviously missing something. Doesn't all evolutionary progression begin with a source of variation (mutational or recombinational), even in the MS?
While mutations are not all equiprobable, they are still random with respect to outcome (except in Shapiro's vision of self-moulding genomes, which I have also seen dubbed 'mutationism').
Not to mention criminal use of ellipsis ...
And furthermore
... - --- .--. / -... . .. -. --. / ... ..- -.-. .... / .- -. / .. -.. .. --- -
Thanks Lou that is such a good example better than Schrödinger's X-rays. Cosmic rays can be described by a wavefunction unlike the X-ray photons in Schrödinger's argument whose interactions with fermions requires QED to explain. However the X-rays could be considered as equivalent to Gamma-ray photons from radioactive decay which also cause mutations.
Schrödinger had used radioactivity as a stochastic quantum mechanical source for establishing a quantum superposition in his famous cat thought experiment. So the equivalence was most likely self evidently trivial to him.
Talking about the cat, I think that
C0|base keto> + C1|base enol>
would last a lot longer before decoherence than
1/2|cat alive> + 1/2|cat dead>
:)
3/16 of one inch is how far Bob would have had to extend his left pinky in order to not sound like a blithering idiot on cocaine.
Also "mutationism" sounds stupidly religious.
Hyperfunctionalism at its best.
or worst.
But is this anything more than the old argument about evolutionary canalization ...
It seems likely, don't you think? Can you imagine writing a whole book when all you have to say is that evolution is contingent? Did you read Arlin's articles?
There are several papers on mutationism. Google is your friend.
"The theory asserts, perhaps somewhat controversially, that the driving force behind evolution is mutation, with natural selection being of only secondary importance."
I can't quite make sense of this sentence. Isn't if the mutation is beneficial, that's natural selection in action? What's the contrasting view mutationism is going up against?
Allan Miller: “I'm obviously missing something.”
I don’t think you are missing anything. Indeed, “all evolutionary progression begins with a source of variation”.
Kel: “I can't quite make sense of this sentence”
I don’t see the rationale behind it either.
Be a mensch, Larry. Cite at least one of them, unless they're all Arlin's. Google is not as much my friend as one might suppose.
No evidence in the world would convince the one brainblocker. I don't care about them..not...really I care about the beat-up, abused, unfortunate people. I'm one of them....
In his upcoming book, Masatoshi Nei outlines Mutation-Driven Evolution as follows:
“…many evolutionists including Motoo Kimura and Jack King believed that phenotypic evolution (in contrast to molecular evolution) is caused primarily by natural selection. By contrast, Nei (1975, 1987, 2007) proposed that since phenotypic evolution is ultimately controlled by DNA and RNA molecules, both molecular and phenotypic evolution must be primarily caused by mutation. Nei’s view has been based on the new findings in the study of molecular evolution and developmental biology. He considered all kinds of DNA changes (nucleotide substitution, gene duplication, polyploidization, epigenetics, etc.) as mutations and tried to explain all phenotypic evolution by mutation. Previously I called this view neomutationism (Nei 1983, 1984), neoclassic theory (Nei 1987), and the new mutation theory (Nei 2007), but in this book I have decided to call it the theory of mutation-driven evolution or neomutationism depending on convenience” (first parenthesis mine).
100 Years of Fruit Fly Tests Show No Evolution
Posted on April 11, 2013 by adonizedek
100 Years of Fruit Fly Tests Show No Evolution
by Brian Thomas, M.S. *
July 22, 2010, marked the 100th anniversary of genetic investigations using fruit flies. The first such study appeared in Science in 1910 and described the unexpected appearance of a male fruit fly with white eyes after generations of flies with pigmented eyes.1 This began a century of focused studies on fruit fly mutations, but what has really been learned by all this tinkering?
For most of the past century–and especially since the discovery of DNA as a physical molecule carrying heritable information–the prevailing concept of neo-Darwinian evolution has held mutations to be the central generator of new and useful information. Thus, mutations have been given ample opportunity to prove themselves, if they are naturally selected, as having “the power to drive the evolution of all living things in the direction of positive improvement.”2
Fruit flies, with their short generation times and only four pairs of chromosomes, presented prime testing ground for evolution. In laboratories worldwide, they have been subjected to all manner of mutation-inducing phenomena, including hosts of chemicals and radiation treatments, to try and accelerate evolution-mimicking mutations. After all this, fruit flies should have certainly exemplified evolution by now.2But they haven’t.
So, having achieved no evolutionary progression in fruit flies by these random means, researchers made them the focus of countless purposeful gene manipulation studies. The most popular, from an evolutionary perspective, were experiments with what are called HOX genes.
HOX, an abbreviation of “homeobox,” are genes used by the organism during embryonic development. Many reasoned that it would be simpler for evolution to operate by mutating these genes, since a small alteration could produce a large effect in the fly’s body. However, this was before recent studies showed that embyronic development is more heavily influenced by regulatory DNA, not genes. And mutating (through substituting, deleting, or duplicating) developmental genes like HOX has only ever yielded a dead fly, a normal fly (if the mutation happened to have no noticeable effect), or a tiny monster. None of these results match the “positive improvement” expected of Darwinian evolution.
Extra body segments, an extra set of wings, or legs in the place of antennae characterized the weird forms that were generated. Three generations of specifically designed DNA alterations were required to produce fruit flies with four wings–but they couldn’t fly. The extra wings had no muscles and were dead weight. One recent exploration of neo-Darwinism remarked:
http://releasingthetruth.wordpress.com/2013/04/11/100-years-of-fruit-fly-tests/
Evolution must be right or left but never true-John Weatengry
"Faith has amazing ability. It can make "intelligent men" believe that belief is science and even find proof for their desires.
I have found 0.00000000000000000000 papers proving the origin of life. It must be true just no one whats to publish cause' nobody wants the heat that comes from being the Creator...hihihi
"We gotta change the THEORY OF BIG FART-BANG!!!-Shitsceintist. Why? Because the big fart-bang points the First Cause, which we cannot handle because we are so perverted and proud we cannot accept reason as an option" hihihi
John Harsh-manure
What should be the reward for misplacing one's logic or brain?
I will give you an example, that Larry can understand. So, I would like to build a doghouse. I already have all the materials and tools to speed-up the self-shiting process. I have the power and all the materials. How long would it take for evolution=accidents to build this pretty simple structure? My Italian neighbor says it would take him 45 minutes. How about the mathematically calculated shit-ific calcu-shitions?
Would 4.2 billion yours suffice or you need a new brain to evolve to think straight? Well, no shit-ist can think like that so you may need some help...hihihi
I am beginning to understand Scott D. Weitzenhoffer's remark about creationists and pigeons.
A John Witton by any other name smells ... well... the same.
It's all fun and games until they come and shit on your chess board.
Alex SL: “This appears remarkably silly”
I posted below an excerpt from Masatoshi Nei's coming book, Mutation-Driven Evolution, in which he outlines the concept of ‘mutation-driven evolution’. Does it change your opinion?
Larry, this seems to conflict seriously with your (and my) preferred definition of evolution. Nei seems to say here that mutation is evolution, and that the spread of those mutant features within a population is unimportant. I'm not sure what new findings support that view, but I guess we'll see.
Kel -- there is an important distinction here. Mutation shapes the direction of evolution far beyond what is and isn't under positive selection. This distinction might appear subtle, especially because everyone will say that they accept that selection can only act when there's variation, implying in principle the primacy of mutation. But the distinction becomes rather more important when you consider that most substitutions are effectively neutral and that not all possible mutations occur with equal likelihood. Because most evolution at the level of nucleotide substitution occurs by escaping natural selection, mutation is the main force that drives the course of evolution.
This contrasts with the idea - traditionally considered correct - that it is selection that is of primary importance. Under this view, mutation might provide the variation but selection does all the "work" to shape organisms into what they are. But this view, too, gives insufficient regard to the bias that mutation gives to evolution even when driven by positive selection.
Finally, the distinction is important because 'natural selection' is very nearly synonymous with 'evolution', while mutation is not.
Do you think it's Witton? Witton is already incredibly stupid, but I think that Bob goes well beyond.
Witton kept posting that same DI blog post about "no evolution in Drosphila". Next will be the post against organellar endsymbiotic theory, written by another DI fellow who thoroughly researched the topic on Wikipedia before launching into their baseball-sharp critique.
John,
You have highlighted an inconsistency I was thinking of noting - Prof. Moran simultaneously espouses Mutationism and the 'shifting-balance' version of evolution from the 'MS' that Arlin Stoltzfus, for example, was critical of in his 'Curious Disconnect' series.
It is undeniable that the sampling of variation, with and without bias, is an important mechanism of 'population evolution' - the kind of evolution that takes place within collections of close ecological competitors such as members of a sexual species (and perhaps any recent asexual offshoots). But I do think that the definition of evolution in terms of population genetics is unsatisfactory. Lineages compete ecologically, whether they can interbreed or not, and that competition can lead to adaptation or drift-mediated extinction of variants. But evolution - as a 'minimal' definition - should not, IMO, be reduced to the latter. Hence: descent with modification. Speciation: descent with modification in disconnected gene pools. Adaptation: Differential propagation of modified descendants in a competitive environment. Drift: Descent with modification with elimination of variants due to sampling effects.
John Harshman: “I'm not sure what new findings support that view, but I guess we'll see.”
Likely, Masatoshi Nei will present some new findings and arguments supporting his theory on mutation-driven evolution. However, as emphasized by the author, he has been promoting this theory under different names (e.g. ‘neomutationism,’ ‘neoclassic theory,’ ‘new mutation theory’) for decades.
Allan,
You are entering a ‘dangerous’ zone here with your rationale and definitions of the fundamental processes of evolution. If you dare to address then in a full page, rather than in half of paragraph, you might leave very little room for any novelty in fundamental evolutionary biology.
John Harshman says: Nei seems to say here that mutation is evolution, and that the spread of those mutant features within a population is unimportant.
Nei - who has made important contributions to our understanding of nucleotide substitution processes in populations - does not say this. He says it starts with mutation, and that by ignoring the influence of this starting point we miss what shapes evolution.
Nei says -- at least according to the bit quoted above -- that mutation is the primary cause of evolution and that all phenotypic evolution is explained by mutation. That doesn't seem to leave much room for other processes. It's trivial to say that evolution must start with mutation, and that mutations that don't happen are not available to be fixed, but quite another thing to say that mutations determine evolution. And certainly "since phenotypic evolution is ultimately controlled by DNA and RNA molecules, both molecular and phenotypic evolution must be primarily caused by mutation" appears to be a non sequitur. Can you cite a publication that clarifies this view? Several are alluded to in the quote, but there are no references.
@Claudiu,
You are entering a ‘dangerous’ zone here with your rationale and definitions of the fundamental processes of evolution. If you dare to address then in a full page, rather than in half of paragraph, you might leave very little room for any novelty in fundamental evolutionary biology.
Sorry, you've lost me!
@Allan,
Sorry, it did not come out the way I intended. I was trying to compliment you on your brief and meaningful definitions of ‘evolution’, ‘speciation’, ‘drift’ and other fundamental concepts. I was also trying to say (in witty way) that if you clarify all these fundamental concepts, what new meaningful concepts or theories would be left there for other people to write about!
@Claudiu,
OK, got it, cheers! :)
Allan, if you're saying that interspecific competition is an evolutionary force in the absence of within-species variation that's relevant to within-species selection, then I agree. Competition can result in extinction, which changes the makeup of the biota, and thus the course of future evolution.
I don't much like your definition of speciation, though. Assuming we limit ourselves to obligate or at least habitual outcrossers, and that we have something resembling the "biological" species concept, speciation is the evolution of genetically-based reproductive isolation between populations. What you're describing is just divergence, which may happen before, during, after, or without speciation.
Paul McBride: “Nei - who has made important contributions to our understanding of nucleotide substitution processes in populations - does not say this.”
I think many readers of this blog are not familiar with the important contributions of Masatoshi Nei to our understanding of nucleotide substitution processes in populations, and they would appreciate if you would describe some of them. Thanks.
Here is another intriguing excerpt from an article by Masatoshi Nei published in 2005 in Mol Biol Evol (available for free at: http://www.ncbi.nlm.nih.gov/pubmed/16120807 ) addressing his mutation-driven evolution theory:
“Kimura (1983) proposed that molecular evolution occurs by random fixation of neutral or nearly neutral mutations, but he believed that the evolution of morphological or physiological characters occurs following the classical neo-Darwinian principle. However, we should note that all morphological characters are ultimately controlled by DNA, and therefore morphological evolution must be explained by molecular evolution of genes. In other words, evolution is not dichotomous as Kimura assumed, and we should be able to find the molecular basis of phenotypic evolution. For this reason, Nei (1975, 1987) presented the view that although a majority of amino acid substitutions may have occurred by random fixation, there must be some substitutions which are adaptive.”
The references used in the text are:
Kimura M. Cambridge University Press; Cambridge: 1983. The neutral theory of molecular evolution.
Nei M. North-Holland; Amsterdam: 1975. Molecular population genetics and evolution.
Nei M. Columbia University Press; New York: 1987. Molecular evolutionary genetics.
John Harshman: It's trivial to say that evolution must start with mutation, and that mutations that don't happen are not available to be fixed, but quite another thing to say that mutations determine evolution.
I don't think it's trivial. The contrast here is between a view that is explicitly grounded in the role that mutation takes in shaping evolution, versus one that ultimately undermines this role by focusing on selection as the driver of evolution.
The distinction is made quite nicely by Stoltzfus and Yampolsky (2009).
And certainly "since phenotypic evolution is ultimately controlled by DNA and RNA molecules, both molecular and phenotypic evolution must be primarily caused by mutation" appears to be a non sequitur.
There's no non sequitur here. We'd all agree that molecular (and higher level) evolution is caused by mutation in the first instance and then shaped by the population genetic processes that follow.
One of the things that Nei argues is that the contribution of mutation is underplayed -- that it is reduced to being a passive supplier of variation instead of playing a central and active role in shaping evolution. This is important because mutation does more than supply variation for selection to act on. Most DNA substitutions are effectively neutral - i.e. not fixed under positive selection. Under neutral theory, these substitutions are absolutely shaped by mutation in terms of rate and composition. And while they may be effectively neutral when they fix, this does not mean they have no effect on phenotype or that they won't affect later evolution (as described in Nei, 2007). Further, while mutation is random with respect to 'need', it is of course biased in composition and position in the genome - a further way in which mutation influences the course of evolution.
Claudiu Bandea: I think many readers of this blog are not familiar with the important contributions of Masatoshi Nei to our understanding of nucleotide substitution processes in populations, and they would appreciate if you would describe some of them. Thanks.
Well, I guess I mean things like developing new phylogenetic methods (e.g. NJ trees) and subtitution models (TN93), and population distance measures (Nei's D), pioneering methods for detecting positive selection, writing volumes on phylogenetics, and helping develop the neutral theory.
Damage is not mutation. Mutation is a biological process. Most mutational processes involve macromolecules and are not subject to quantum-mechanical uncertainty. A polymerase might make an error without any input from quantum uncertainty.
However, the path of a photon (that might cause damage) clearly *is* subject to quantum mechanical uncertainty. Therefore, it is undeniable that *some* mutations reflect quantum uncertainty.
This difference hardly matters for most purposes, because mutations are subjectively unpredictable (we can't know enough, and calculate enough, to predict the next non-quantum mutation from the positions and momentums of all the molecules in a cell).
John,
I don't much like your definition of speciation, though. Assuming we limit ourselves to obligate or at least habitual outcrossers, and that we have something resembling the "biological" species concept, speciation is the evolution of genetically-based reproductive isolation between populations. What you're describing is just divergence, which may happen before, during, after, or without speciation.
OK, it was a bit of a sound-byte ... as you say, there is an issue that these processes are all extended in time. There is a point at which a population is fully mixed, and one at which two divided and diverged subpopulations are definitely not - the (unknown) point at which the last possible compatible gametes are lost. In between is a drawn-out process of divergence during which the subpopulations may or may not be in potential contact, followed by the inaudible 'pop' when they are fully unzipped - they could no longer produce fertile offspring in any circumstances. Would we call the entire period 'speciation', or the final moment, or something else? Once it's complete, it doesn't matter - it's a node on the tree. But I disagree that speciation is restricted to the evolution of genetic (or niche-based, or sexual selection) mechanisms among subpopulations in contact. The barrier may be semi-permeable, with introgression, or fully impermeable - such as geography. In a sense, divergence is always in train, but sex serves to keep the population stirred. But that mixing is not particularly efficient, and sometimes it merely takes excision of the middle to complete the process - see the circumpolar gulls. Some of the 'modification' goes on before the split (and is partly responsible for it). But regardless of the initial mechanism, once complete, what prevents interbreeding is the 'modification' part - evolution in partly or completely divided gene pools.
But I disagree that speciation is restricted to the evolution of genetic (or niche-based, or sexual selection) mechanisms among subpopulations in contact.
So do I. (And, by the way, the circumpolar gulls are not actually a ring species.) My point is that one can't describe speciation just as modification. It's a restricted percentage of modification: that which, by drift, selection, or as a byproduct of selection on something else, results in reproductive isolation. This can, and most often probably does, happen in allopatry, but that's not relevant to the definition either.
Actually the term "mutationism" is not new.
I agree that Nei tends to mis-frame the issues. Talking about mutation as "driving" evoution and saying that selection is "secondary" smacks of the way that evolutionists talked about evolution in the past, when they were trying to identify the One Principle That Rules Evolution. It seems like Nei is saying that mutation is the great principle of evolution, and selection is a secondary principle.
If that were all that could be said on the subject of mutation and reform, it would be a foolish book, but we know from Nei's past work that his book will be chock full of facts and arguments about evolution.
But I think you are implying that starting an argument is bad for science. I couldn't disagree more. It depends on whether the argument is clearly framed, and whether it is framed in a way that multiple parties can agree (to some extent) on how the disagreement is defined.
If the Modern Synthesis is inadequate, then we should be talking about alternatives.
@Paul McBride
Thanks for outlining some of Masatoshi Nei’s contributions. It would be great if you could also address (focusing on novelty) the intriguing statements made by Nei in the two excerpts above. If I understand correctly, according to Nei:
1. The idea promoted by Kimura and other evolutionists that, unlike molecular evolution, the evolution of morphological or physiological characters (i.e. phenotype) is caused primarily by natural selection is flawed. Instead, Nei thinks that both molecular evolution and the phenotypic evolution are caused primarily by mutations.
2. Moreover, unlike Kimura and some other evolutionists, Nei thinks that:
(i) “all morphological characters are ultimately controlled by DNA, and therefore morphological evolution must be explained by molecular evolution of genes”, and that
(ii) “there must be some (amino acids) substitutions which are adaptive” (parenthesis mine).
Paul McBride: “The distinction is made quite nicely by Stoltzfus and Yampolsky (2009)”
In a more recent and very interesting paper, “Constructive neutral evolution: exploring evolutionary theory's curious disconnect” (available for free at: http://www.ncbi.nlm.nih.gov/pubmed/23062217), Alan Stoltzfus discusses the paradigm that: “mutation is not a source of raw materials, but an agent that introduces novelty, while selection is not an agent that shapes features, but a stochastic sieve”.
The peer review evaluations of his paper are also revealing. Here are some excerpts:
Reviewer’s report 1(Alex Kondrashov): “It is hard for me to provide a useful review for this manuscript, because it consists, almost exclusively, of rather general reasoning, instead of precise, falsifiable statements…. I do think that our understanding of evolution at the level of sequences already matured past the phase when discussions of basic principles are useful for professionals. We all believe in mutation, selection, and drift, I hope”.
Reviewer’s report 2 (Eugene Koonin): “In my opinion, this is a truly excellent article that presents an exceptionally clear and well-written account of constructive neutral evolution, its underlying mechanisms and implications…. I would only like to add that the contribution of mutations to evolution does not stop at biases. It is clear now that a variety of mechanisms exist for directing mutations to specific targets that are relevant for adaptation under the given conditions” (emphasis mine).
Reviewer’s report 3 (Johann Peter Gogarten):
I found Arlin Stoltzfus's description refreshing and convincing, and I have been a fan of neutral pathways towards complexity ever since. Other earlier writings by Arlin Stoltzfus that I highly enjoyed reading were the guest blogs he wrote for Larry Moran's Sandwalk blog”
Interesting discussion. Above I asked whether/how Nei's position is different from the nearly neutral theory and from Kimura's world view. Asking about Kimura was the wrong question, because the nearly neutral theory is due to Ohta (1973, with follow-ups in the early 90s), and I don't know to what extent Kimura took it on board (though I don't see why he wouldn't have - it was a refinement of his work by his student). Ohta's nearly neutral theory was an important advance, to the extent that after 1973 (let alone 40 years later) anyone criticizing Kimura while ignoring Ohta is attacking a straw man and reinventing the wheel.
Assuming Claudiu's summary of Nei's position is correct, I'm struggling to understand where the viewpoint he is setting himself up against is coming from. Could someone point to evidence (besides Nei's say-so) of researchers in molecular evolution advocating any of these implied views after 1973?
1) phenotypic evolution is caused primarily by natural selection (I guess for the purpose of discussion we have to ignore the problems with whether or how "caused primarily" can be quantified)
2) morphological evolution must not be explained by molecular evolution of genes (seriously?)
3) no substitutions are adaptive (seriously?)
To repeat my original question: in what way is the worldview promoted by Nei distinct from the nearly neutral theory?
Re whether probabilities are classical or quantum, I would point out that QM was developed and is usually exposited based on classical probabilities, that the notion of quantum probabilities was only introduced in the 1980s (http://en.wikipedia.org/wiki/Quantum_probability), and that it is not clear whether they add anything useful not already present in classical probability. See the discussion below this blog post: http://andrewgelman.com/2013/05/15/does-quantum-uncertainty-have-a-place-in-everyday-applied-statistics/
also, this: http://models.street-artists.org/2013/05/23/quantum-probability-bells-theorem-and-one-of-the-best-articles-ive-ever-seen-on-qm-thanks-to-scholarpedia/
Arlin and Konrad, there is an important philosophical difference between quantum uncertainty and ordinary ignorance-based uncertainty. Since some mutations are quantum-mechanically uncertain events, evolution is not a strictly deterministic classical process. If we could run it again, it would give different results.
LJ
Ignorance-based uncertainty is an appropriate description regardless of whether nature (or a particular aspect of it under discussion) is deterministic or non-deterministic. If a process is non-deterministic, that doesn't make us any less ignorant or uncertain when it comes to predicting the outcome.
" 'natural selection' is very nearly synonymous with 'evolution' "
Cough, splutter... methinks you've been hanging out with the wrong crowd.
Really? I'm not sure if you read the rest of my comment, but it should have be fairly obvious that the remark you quotemined was about general perceptions of evolution and not my own.
Konrad, in the deterministic case, it is only ignorance that prevents us from predicting the outcome, and it is at least in principle conceivable that we could reduce our ignorance and make better predictions. The QM case is very different: there are no causes for a particular outcome, and complete knowledge of prior states is not enough to predict it.
LJ
Even in the deterministic case it is not conceivable that we could have complete knowledge of prior states - such knowledge would have to include complete knowledge about every particle in the universe (and the universe would have to be deterministic). If an extension of probability were required for nondeterministic systems, it would also be required for deterministic systems.
I might also point out that not everyone supports the Copenhagen interpretation of QM, or nondeterminism more generally - the jury is still out on whether the universe is nondeterministic.
While discussing the merit of mutation-driven evolution, it might be relevant to also bring forward the validity of the Neutral Theory, the other questionable perspective on evolution.
One of the most important papers evaluating Neutral Theory is “Toward a selection theory of molecular evolution” (http://www.ncbi.nlm.nih.gov/pubmed/18302709) by Matthew Hahn.
Unfortunately the paper is behind a pay wall so here are some excerpts:
“Since the proposal of the Neutral Theory, every few years has seen the publication of a paper summarizing data that challenge its preeminence (e.g., Gillespie 1984; Kreitman 1996; Fay and Wu 2001). However—and despite the mounting evidence of natural selection that each successive author has been able to draw upon— the general conclusion has always been that even though we do not necessarily believe the Neutral Theory, neutral models are easier to parameterize and provide a clear null model. The title of Kreitman’s 1996 review sums up this feeling: “The neutral theory is dead. Long live the neutral theory.” In the following I outline some of the reasons why neutral models have had such staying power, but why continued use of the Neutral Theory as a guiding framework can positively mislead researchers and skew our understanding of nature.”
“However, the overwhelming evidence from studies of molecular variation does not support the Neutral Theory, and therefore neutral explanations are arguably not more parsimonious given all of the evidence. The consequence of this is that we have tied ourselves into philosophical knots by using null models no one believes but are easily parameterized.”
“Whatever the general conclusions drawn, it is clear that adherence to the Neutral Theory in the face of mounting evidence for selection is unwarranted, despite the intellectual effort required to shift our view. It is simply inconsistent to claim both that there are high rates of adaptive evolution and that the Neutral Theory is an adequate description of nature”
[“When the facts change, I change my mind. What do you do sir?” —John Maynard Keynes]
The Hahn paper does not cite the nearly-neutral theory.
As Konrad said, "Ohta's nearly neutral theory was an important advance, to the extent that after 1973 (let alone 40 years later) anyone criticizing Kimura while ignoring Ohta is attacking a straw man and reinventing the wheel."
Are you saying that Masatoshi Nei, and for that matter the hundreds of not thousands of biologists/evolutionists promoting Neutral Evolution during the last few decades have been missing the boat?
Nei is not re-proposing the Neutral Theory, as is clear from his other publications, e.g., http://www.pnas.org/content/104/30/12235 . He is not summarizing or reiterating what others are saying. Nei is making a novel proposal.
I won't try to state his theory, because I am not sure what it is. I'm not going to make excuses for Nei: frankly, he has done a poor job explaining himself in the past.
But I can help by describing the events of the 1960s and 1970s that shape Nei's perspective. Mayr, et al had just finished "unifying biology" with the Modern Synthesis (MS): the "gene pool" automagically maintains abundant variation, so that a creative and largely deterministic process of selection can build complex adaptations by shifting gene frequencies, without a direct dependence on new mutations. They perpetuated the orthodoxy in _Evolution_, and marginalized all rivals, including the "mutationist" view that selection is not creative but acts as a filter on mutations.
Mayr's great unification lasted about 35 seconds. Biochemists, not baptized in the faith, compared proteins and interpreted evolution as a stochastic Markov process with characteristic rates. They re-invented the language of the mutationists, referring to evolutionary changes as "mutations" and invoking selection as a filter or editor. They proposed a "molecular clock" and a "neutral theory" in which the rate of evolution reflects the rate of mutation.
To preserve orthodoxy, Mayr, et al had to explain why molecular evolution *did not look like what they had expected*. From their perspective, an internally determined rate of evolution, proportional to the mutation rate, was a heresy that smacked of vitalism.
Within a few short years, a compromise emerged that, in retrospect, seems absurdly superficial: "molecular" evolution is different from "evolution" or, at least, it *looks* different. Previously, there was 1 discipline of biology, and 1 theory of evolution that made sense of "everything in biology". What made "molecular" evolution different? Mayr and Simpson proposed that molecules reveal the proximate causes of change, but not the ultimate causes evident at the phenotypic level, i.e., molecular evolution opens a new-- but superficial-- window on the old MS process.
Some people accepted that. Others decided that molecular evolution doesn't just *look* different, but *is* different, due to neutral evolution. In Kimura's view, neutral change happens at the "molecular" level, but phenotypic change is entirely separate and follows the MS orthodoxy.
Evolutionary biology was thoroughly disunified. The new field of "molecular" evolution had its own journal, JME. The dichotomy is evident in Jack King's "The Role of Mutation in Evolution" (http://projecteuclid.org/DPubS/Repository/1.0/Disseminate?view=body&id=pdf_1&handle=euclid.bsmsp/1200514593). King (p 70-71) recites the MS view on the role of mutation and then contrasts it with a mutation-driven view that includes neutral *and beneficial* mutations, a view that applies on the "molecular level".
Nei didn't accept this dichotomy. Like King, Nei believed that the key to molecular evolution is not its alleged neutrality, but the role of mutation in dynamics. Unlike King, Kimura and Mayr, Nei did not agree that non-molecular evolution looks just like what the MS predicts. He had a greater expectation of unity, and he left open the possibility that the disunity might be resolved by finding that the mutation-driven view applies beyond the molecular level.
Now, after decades, Nei is trying to bridge the gap and bring morphological evolution into his mutation-driven view.
While Nei's presentation may prove inadequate, I look forward to mining his book for data and arguments.
No. I'm saying that the Hahn paper went after the flaws in Neutral Theory, and most of those are dealt with very well under the Nearly Neutral Theory.
In his article, “Toward a selection theory of molecular evolution”, Hahn makes the case that the current data supports the paradigm that molecular evolution is driven by natural selection and that this data is inconsistent with the neutral theory.
Also, as clearly indicated in the first paragraph of Kimura’s book “The Neutral Theory of Molecular Evolution” (1983), the neutral theory also covers ‘nearly neutral mutants’:
“The neutral theory asserts that the great majority of evolutionary changes at the molecular level, as revealed by comparative studies of protein and DNA sequences, are caused not by Darwinian selection but by random drift of selectively neutral or near neutral mutants’ (emphasis mine)
Does this clarify some of the issues raised obove?
Arlin,
Thanks for your insightful perspective. However, I would like to clarify that in his upcoming book “Mutation-Driven Evolution” Masatoshi Nei might present additional evidence and arguments for mutation-driven evolution, but as described in the following early released excerpt from his book, we have known his theory for decades:
“…many evolutionists including Motoo Kimura and Jack King believed that phenotypic evolution [in contrast to molecular evolution; this parenthesis mine] is caused primarily by natural selection. By contrast, Nei (1975, 1987, 2007) proposed that since phenotypic evolution is ultimately controlled by DNA and RNA molecules, both molecular and phenotypic evolution must be primarily caused by mutation. Nei’s view has been based on the new findings in the study of molecular evolution and developmental biology. He considered all kinds of DNA changes (nucleotide substitution, gene duplication, polyploidization, epigenetics, etc.) as mutations and tried to explain all phenotypic evolution by mutation. Previously I called this view neomutationism (Nei 1983, 1984), neoclassic theory (Nei 1987), and the new mutation theory (Nei 2007), but in this book I have decided to call it the theory of mutation-driven evolution or neomutationism depending on convenience”
It's a good paper (one that Larry in particular ought to read :-) ) - thanks for pointing to it. It's actually available for free here: http://onlinelibrary.wiley.com/doi/10.1111/j.1558-5646.2007.00308.x/full
I would have framed it differently though - to my mind, work in this direction extends rather than replaces Kimura's framework. Perhaps it depends on whether one sees the core of Kimura's contribution as a conceptual (mathematical) framework or as empirical claims.
Thanks for that, Arlin.
I am still trying to understand how these views are different from each other. Surely you can't be saying that in the MS evolution is _not_ a stochastic Markov process? Then what is it? (It is a process by definition; it is best described as stochastic because we cannot ever have the detailed information required to describe it as deterministic; and we don't seem to have any reason to describe it as non-Markovian.)
Is the only difference whether or not standing variation is negligible, or does MS also differ in other ways?
Mutations? What a disaster in evolutionary brainwash. This is not the end of it. We are doing studies that prove beyond any doubt that "monkeys", such as chimpanzees and humans can't mix. There are genetic barriers that can' be overcome... There is no way to overcome it... We are going to publish it in November or December.
I have no problem believing that you have been trying to "mix" with chimpanzees, who by the way have my sympathy.
I hope that you at least sent the poor monkey some flowers and perhaps nice box of chocolates.
I'll be keeping an eye out at the checkout on my favourite supermarket tabloids for your "paper".
Can you perhaps give us a hint, will it be the "World Weekly News" and will your "paper" get front page coverage like the exciting series of articles on the FBI capture of a bat child and Hillary Clinton's recent adoption of an alien baby ?
And will it have pictures ?
Don not forget the question you demanded so badly. Even morons like can read from time to time how much money; how many billions of dollars are is being spent all over the world so that people can save 1 stat day of their life. I mean this is only possible in the world of so called science is not it?
Will this 1 day of life that I save be a paid holiday or a working day ?
How did you come up with those figures, Vashti? Not thru science, I presume, because otherwise your argument is self-defeating.
In Canada Larry and I, I hope, spell thru (through) that's just a norm? Larry, I'm not sure about your courses but mine where biology based it as much as should be............
Is that meant to be an answer, Vashti>
Please Vashti, study tracts by Robert Byers to gain some skills in expository lucidity (baby steps toward clarity).
Another moron....Evolution, pls help me to deal with this overwhelming idiosyncrasy...... Would you like to take a bet? I say within 1-5 years it will be obvious, because it is now to us, that the mechanism of macro-evolution will fade. I already has. Mutations are garbage. Natural selection is s..t. Pardon my french. What is left? Genetic drift because Mr. WHO says it is so....?
I finished my Phd 5 years ago when genetic mutations and the tree of life where in it's prime. What happened to them? Tell me? Can you provide me with some kind of proof, so that I wouldn't have to cry. Give me more then theory because I have my own. Many
1. Evolution is not a person and can't help you deal with anything.
2. Nobody will be able to take your bet because nobody can tell what the bet is. That's because you just can't communicate, whatever the reason may be.
3. I doubt anyone here is willing to believe you could have a Phd in any field, much less biology. I could be wrong about that, but you do give off an impression of near-total ignorance.
4. Nobody is clear on what you're asking for proof of either.
5. Given your clear ignorance (see #3), I don't think anyone here is interested in your theories, whatever they may be.
I think learning to write clear, grammatical sentences that communicate your thoughts would be a big advantage for you. I concur with SRM that you should concentrate on that, though his advice that you use Byers as an exemplar was facetious.
I look forward to the review. Please consider comparison of Mutation-driven evolution to the biological facts represented in Nutrient-dependent/pheromone-controlled adaptive evolution: a model. http://www.socioaffectiveneuroscipsychol.net/index.php/snp/article/view/20553
I've always preferred biological facts to theories, and am continually surprised when others prefer their theories.
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