More Recent Comments

Wednesday, June 16, 2021

Is the Modern Synthesis effectively dead?

The Modern Synthesis is the version of evolutionary theory popularized by Julian Huxley and supported by the leading evolutionary biologists of the 1930s, 40s, and 50s.

The general idea was to merge Dawrin's view of natural selection with the relatively new field of population genetics. Evolution was now defined as a change in allele frequencies in a population and the emphasis was on natural selection as the most important mechanism although, in the original version by Huxley, the fixation of alleles by random genetic drift can occur in small populations. By the early 1960s the most popular vesion of the Modern Synthesis focused almost exclusively on natural selection—an emphasis that's referred to as the hardening of the synthesis. It was this excessively adaptationist view of evolution that led to Gould and Lewontin's paper on "The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme" (Gould and Lewontin, 1979).

In Gould's classic 1980 paper on "Is a new and general theory of evolution emerging?" (Gould, 1980), he argues that the current view of the Modern Synthesis is defined by scientists like Ernst Mayr who says,

The proponents of the synthetic theory maintain that all evolution is due to the accumulation of small genetic changes, guided by natural selection, and that transspecific evolution is nothing but an extrapolation and magnification of the events that take place within populations and species.

If this is the correct view of the Modern Synthesis then it is "effectivly dead" for several reasons. Those reasons are better explained in his Tanner Lecture at Cambridge University (UK) in 1984 (Gould, 1984). He lists three major challenges to the Modern Synthesis.

  1. The role of chance. The development of Neutral Theory has revealed a much greater role for random genetic drift than the proponents of the Modern Synthesis recognize.
  2. Hierarchical perspective. The individual is no longer the exclusive agent of evolution because evolution can also occur at the level of genes, demes, species, and monophyletic clades. This, in turn leads to the recognition that macroevolutionary change, including but not restricted to punctuated equilibria, cannot be fully explained by microevolution.
  3. Critique of adaptation. The role of adaptation is constrained by non-adaptive features.

Jerry Coyne recently posted an attack on punctuated equilibria, which he believes is "effectively dead" [Punctuated equilibrium is dead; long live the Modern Synthesis]. He may or may not be correct about punctuated equilibria but it's only a part of the criticism of the Modern Synthesis and now is not the time to resurrect it. In my opinion, it wasn't Gould that killed the Modern Synthesis, it was King & Jukes and Kimura.

... I would like to emphasize the importance of random genetic drift as a major cause of evolution. We must be liberated, so to speak, from the selected constraint imposed by the neo-Darwinian (or the synthetic) theory of evolution.

Mootoo Kimura (1991)

There are some scientists who think that the Modern Synthesis evolved in the late 1960s to incorporate the fact that random genetic drift is the most common mechanism of evolution. According to these scientists, Neutral Theory, Nearly-Neutral Theory, the Drift-Barrier Hypothesis, Mutationism, and a host of other concepts have been absorbed by the Modern Synthesis so it's still possible to refer to modern evolutionary theory as the Modern Synthesis. Douglas Futuyma is an important proponent of this idea (the ongoing evolution of the Modern Synthesis) and so, apparently, is Jerry Coyne although he doesn't mention the Modern Synthesis in his book "Why Evolution Is true." Other evolutionary biologists take a slightly different position; for example, Brian Charlesworth says that the "core tenet" of the Modern Synthesis is that adaptive evolution is due to natural selection and that's still as true today as it was in the 1930s and 1940s (Charlesworth et al., 2017).

I side with those who say that the Modern Synthesis was an adaptationist view of evolutionary theory (i.e. Darwinism) and we should abandon that term and talk about modern evolutionary theory instead of a particular version promoted by the likes of Ernst Mayr. In that sense, I align with textbook authors such as Michael Lynch and Dan Gaur who stopped using the term "Modern Synthesis" many decades ago and I agree with Eugene Koonin who says,

In the post genomic era, all major tenets of the modern synthesis have been, if not outright overturned, replaced by a new and incomparably more complex version of the key aspects of evolution. So, not to mince words, the modern synthesis is gone. (Koonin, 2009).

This is a complex issue made even more complex by the fact that Neutral Theory and the role of random genetic drift are not well-understood by most biologists, even by evolutionary biologists who deal mostly with living species. I like the way Austin Hughes describes the problem while taking a swipe at one of Stephen Jay Gould's most viscious opponents.

Given the importance of his contribution, it is not an exaggeration to say that Kimura was the most important evolutionary biologist since Darwin. What is perhaps surprising in Kimura’s case, given the impact of his work on the biological sciences, is that its significance has so far been little appreciated by the general educated public or by philosophers and historians of ideas. To take one example, a recent book entitled Evolution: the History of an Idea (Larson 2004) includes not a single mention of Kimura. To my mind, this is rather like writing a history of physics without mentioning Einstein.

The philosopher Daniel Dennett, in his book "Darwin’s Dangerous Idea," proposes that Darwin’s key (and “dangerous”) insight was that evolution is an “algorithmic process." By “algorithmic,” one gathers that Dennett means essentially deterministic. But determinism was hardly a bold or “dangerous” idea in Darwin’s time, having been a familiar concept in Western thought since at least the Stoics. Rather, one might suggest that the truly new idea in evolutionary biology is that of Kimura (building on the work of Sewall Wright), which along with Heisenberg’s Uncertainty Principle and Gödel’s proof of the incompleteness of mathematics, formed part of a Twentieth Century revolution in thought that for the first time revealed the universe as non-algorithmic.

I've posted a lot on the death of the Modern Synthesis and so has Arlin Stoltzfus—who is much, much more knowledgeagable on the topic. Here's a list of posts over the past 14 years.



Charlesworth, D., Barton, N.H. and Charlesworth, B. (2017) The sources of adaptive variation. Proc. R. Soc. B 284:20162864. [doi: 10.1098/rspb.2016.2864]

Gould, S.J. and Lewontin, R.C. (1979) The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme. Proceedings of the Royal Society of London. Series B. Biological Sciences 205:581-598. [doi: 10.1098/rspb.1979.0086]

Gould, S.J. (1984) Challenges to Neo-Darwinism and Their Meaing for a Revised View of Human Consciousness. The Tanner Lectures 1984 reprinted in "The Richness of Life: The Essential Stephen Jay Gould." S. Rose ed. (2006) New York, W.W. Norton & Company: 222-237.

Hughes, A.L. (2008) Near-neutrality: the leading edge of the neutral theory of molecular evolution. Annals of the New York Academy of Sciences 1133:162-179. [doi: 10.1196/annals.1438.001]

Kimura, M. (1991) Recent development of the neutral theory viewed from the Wrightian tradition of theoretical population genetics. Proceedings of the National Academy of Sciences 88:5969-5973. [PDF]

Koonin, E.V. (2009) The Origin at 150: is a new evolutionary synthesis in sight? TRENDS in Genetics 25:473-475. doi: [doi: 10.1016/j.tig.2009.09.007]

41 comments :

  1. I would agree with Jerry on one thing: PE isn't just dead. It was stillborn, as it incorporated a number of fatal flaws from the beginning. Of course that didn't stop it from becoming popular, though mostly with paleontologists. And that doesn't have much to do with the death or otherwise of the modern synthesis.

    Gould's major contribution to biology is in being one of the early advocates of statistical testing against null models and the use of stochastic models in paleontology. OK, also maybe a bit about heterochrony, canalization, spandrels, and species selection.

    ReplyDelete
    Replies
    1. Your view (and Jerry's) is not universal except when punctuated equilibrium (the pattern) is confused with postulated mechanisms that give rise to the pattern.

      Here's an interesting paper that makes this point.

      Lieberman and Eldredge (2014) What is punctuated equilibrium? What is macroevolution? A response to Pennell et al. Trends in Ecology and Evolution 29: 185-186 [doi: 10.1016/j.tree.2014.02.005

      Delete
    2. What pattern? PE originally was a theory of stasis except during peripatric (only a small subset of allopatric) speciation events. Stasis is hard to test in the fossil record, punctuation even harder, and speciation pretty much impossible. That paper evinces a confusion regarding species concepts which is one of the fatal flaws of PE.

      Delete
    3. Hi Larry Moran,

      how about this, for example:

      Pfenninger et al (2015): Unique Evolutionary Trajectories in Repeated Adaptation to Hydrogen Sulphide-Toxic Habitats of a Neotropical Fish (Poecilia mexicana). Molecular Ecology. https://doi.org/10.1111/mec.13397:

      “Our findings favour Gould's view that evolution is often the unrepeatable result of stochastic events with highly contingent effects.”




      Cheers,

      Lamarck

      Delete
  2. "This, in turn leads to the recognition that macroevolutionary change, including but not restricted to punctuated equilibria, cannot be fully explained by microevolution."

    Please elaborate on what you mean by this, because I'm tired of having to explain to creationists that you(and other scientists making similar statements) don't mean by this that there is some evolutionary transition between a descendant and it's ancestor that is not explained by a combination of mutations(of all types including HGT), recombination, natural selection, and genetic drift.

    What they take a statement like yours to imply is that the "usual" mechanisms of evolution are somehow not up to the task of explaining something like the evolutionary transition from terrestrial to aquatic mammals, or from fish to tetrapods. Which becomes an excuse to think magic has to be involved.

    But unless I'm mistaken, that's not what you're saying. So what are you saying? I could take a guess but I'd rather you elaborate.

    ReplyDelete
    Replies
    1. In the paper I referenced above the authors define macroevolution as "the patterns and processes pertaining to the birth, death, and persistence of species."

      The debate can get complicated but one of the issues involves the formation of a new species by, for example, cladogenesis (allopatric speciation). Microevolutionary processes such as the change in allele frequencies within a population are not sufficient to explain this event. You also have to take into account geographic isolation.

      Mass extinctions are an even more obvious example. They are significant events in macroevolution but can't be sufficiently explained by microevolution.

      The problem with the standard myth that microevolution is sufficient to explain all of macroevolution is that it makes the assumption that all species form by gradual transformation of one species into another but that really doesn't account for diversity.

      It's important to note that every new species is, of course, a product of changing alleles in populations over time so that means that microevolution is a necessary component of that kind of macroevolutionary change. It's just not sufficient.

      Delete
    2. Species sorting, including species selection, is another clear example of a macroevolutionary process that can't be sufficiently explained by microevolution alone. Species sorting may or may not exist but it at least serves as a good example of what macroevolutionary evolutionists are talking about.

      Delete
    3. The problem with the standard myth that microevolution is sufficient to explain all of macroevolution is that it makes the assumption that all species form by gradual transformation of one species into another but that really doesn't account for diversity.

      Now don't lay that rap on Jerry Coyne. After all, he wrote a whole book to say that allopatric speciation is the dominant mode, and it mostly happens as a byproduct of selection in two geographically isolated populations. Each of those populations is experiencing microevolution independently.

      Species selection is a much better example, as it can't be reduced to allele frequency change in any population or populations.

      Delete
    4. "In the paper I referenced above the authors define macroevolution as "the patterns and processes pertaining to the birth, death, and persistence of species."

      The debate can get complicated but one of the issues involves the formation of a new species by, for example, cladogenesis (allopatric speciation). Microevolutionary processes such as the change in allele frequencies within a population are not sufficient to explain this event. You also have to take into account geographic isolation."


      Good, thank you. So in essence, you are here thinking of factors that contribute to speciation and species diversity. This has nothing to do with the magnitude of anatomical, genetic, or physiological changes that occur during evolution.

      "The problem with the standard myth that microevolution is sufficient to explain all of macroevolution is that it makes the assumption that all species form by gradual transformation of one species into another but that really doesn't account for diversity."

      So again, if I understand you correctly, you're concerned here with the formation of new reproductively isolated populations, that is species. Not with the causes of change between an ancestral and descendant population.

      I take your last paragraph to mean you'd still say that the reason an ancestral population changed morphologically, behaviorally, and genetically into a descendant population during some macroevolutionary transition is because of all the usual stuff: Mutations, recombination, HGT, selection, and drift. But that (for example) one of the contributing causes to speciation events was that a reproductive barrier formed (geographically, behaviorally, or otherwise), or perhaps an occupied niche became open because the occupant species went extinct. Is that a fair characterization of your words?

      Delete
    5. I would suggest that the K/T extinction is a fine example of species selection, as species became extinct (or not) largely as a result of the way in which their fixed phenotypes reacted to a very short-term environmental stress.

      Delete
    6. @Mikkel

      I don’t have a dog in this race. I’m just trying to accurately portray the views of those whose main interest is macroevolution. I think it’s been too easy to misrepresent those views.

      Delete

    7. Hi Larry Moran,

      if evolution represents the transformation from n to n', then the distinction between micro- and macroevolution is only a scaling problem. Perhaps the easiest to see is the phenomenon of ring species: Locally volatile in a manageable way, but as a whole it no longer fits together. The notion of macroevolution is also not necessary to describe the clusters in the fossil record as stasis: This is a random pattern similar to Gould's undirected path of the drunk between the inn on the left and the street on the right, leading sooner or later to the local maximum of the trickle (= Chance and Necessity).




      Cheers,

      Lamarck

      Delete
    8. Hi John Harshman!

      “I would suggest that the K/T extinction is a fine example of species selection, as species became extinct (or not) largely as a result of the way in which their fixed phenotypes reacted to a very short-term environmental stress.”

      Maybe that's helpful for you:

      Lyson, T. et al. ( (2011): Dinosaur extinction: closing the ‘3 m gap’. Biol. Lett. 7 (6), 925–928. https://doi.org/10.1098/rsbl.2011.0470.
      Hull, P. M. et al. ( (2020): On impact and volcanism across the Cretaceous-Paleogene boundary. Science 367 (6475), 266–272. https://doi.org/10.1126/science.aay5055.

      Without the Chicxulub impact, the gods would be reptiles today purely by chance.




      Cheers,

      Lamarck

      Delete
  3. My 2 cents: I call the current views on evolution The Modern Synthesis. You may want to call it something else. That's fine with me, this is just an argument about names, not about what processes are responsible for evolution. And keep in mind that a lot of the debates about this are affected by self-interest. John Blotz wants to be known as the guy who killed off The Modern Synthesis, and he secretly hopes that people will consider his new synthesis The Blotzian Synthesis. (Which will probably only be around for about 2 years, if the process continues). See: The Extended Evolutionary Synthesis, soon to be replaced by the Hyperextended Evolutionary Synthesis, and after that by the New!! Improved!! Evolutionary Synthesis. Not to mention The Third Way of Evolution, which is not even a Way, but is about 60 different Ways, all mutually incompatible. Or we could give up talking about the name and go back to talking about evolution.

    ReplyDelete
    Replies
    1. You may be comfortable referring to your view of evolution as the Modern Synthesis but the problem is that there are lots of biologists who use the term to refer to the 1950s version. If everybody calls their different versions of evolutionary theory by the same name then that can be very confusing. It’s not just a semantic argument about names; it’s a substantive argument about which version is correct.

      Delete
    2. If everybody calls their different versions of evolutionary theory by the same name then that can be very confusing.
      And correspondingly, if everybody calls there only slightly different versions of evolutionary theory by different names, it can be equally confusing.

      Delete
    3. So I suggest we don’t give specific names to specific versions of evolutionary theory and just refer to “evolutionary theory.” That way we avoid terms like “Darwinism,” NeoDarwinism,” “Modern Synthesis.” and “Extended Modern Synthesis.”

      Delete
  4. To Larry's reference list we should add the work of historian Mark B. Adams. He has an "apologia" due out in the July issue of the History of Science Society Newsletter. Here he regrets that a paper he initially published in a French journal (1990) has only recently (after decades of "samizdat" circulation) formally appeared in English. The reference is:

    Adams MB (2021) Little evolution, BIG evolution: rethinking the history of Darwinism, population genetics, and the “synthesis”. In: Natural Selection - Revisiting Its Explanatory Role in Evolutionary Biology. R. G. Delisle (ed), Springer-Nature, Switzerland AG, pp. 195-230.

    ReplyDelete
    Replies
    1. This URL takes you directly to the Newsletter where Adams' piece is on page 5: Here

      Delete
    2. Interesting. Will have to see whether I can get my hands on the actual Adams article it mentions. Though if he concludes that evolutionary biologists never provided enough evidence that microevolutionary processes can account for macroevolutionary change, I will retain my counsel in view of the fact that he is not a biologist.

      Delete
  5. I never understood why evolutionists can afford to ignore plants and bacteria and assume that all the evolutionary mechanisms and dynamics they postulate for dinosaurs and birds should be universal. I also think SJ Gould was prolific science popularizer but I always failed to see his real scientific contribution. Kimura, on the other hand, was definitely on the ball about neutrality but his papers were difficult to read due to the complex mathematics. That he was not white, English-speaking and tenured in Harvard probably made it easy to ignore him.

    ReplyDelete
    Replies
    1. Nobody ignores plants and bacteria. Evolution journals are full of papers on plants and bacteria.

      And Gould had a number of real scientific contributions beyond PE. Founding of the journal Paleobiology, introducing stochastic null models into paleontology, work with heterochrony, etc.

      Delete
    2. Nor does anyone ignore Kimura. What are you talking about?

      Delete
    3. No, John, you don't understand. Kimura was not white, English-speaking and never attended Harvard, so his work must have been ignored. Huinca knows that, and so does not need to check with Wikipedia. Where Huinca would have found that Kimura received the following honors:
      * Weldon Medal from Oxford University
      * Election as a Foreign Member to the U.S. National Academy of Sciences
      * Chevalier de l'Ordre Nationale de Merite from France
      * Carty Award from the U.S. National Academy of Sciences
      * Darwin Medal of the Royal Society
      * Election as a Foreign Member of the Royal Society
      (I leave out a number of awards in Japan)
      Huinca just knows, just as in the case of evolutionary biologists not working on plants or bacteria.

      Delete
    4. Actually, Kimura spoke English pretty well, accented but fairly clear. He also got good enough in writing English that Jim Crow, who had helped with the English in his early papers, no longer needed to help out.

      Delete
  6. evolutionary biologists not working on plants or bacteria.

    Wasn't Brian Charlesworth even mentioned here quite recently?

    ReplyDelete
    Replies
    1. He's certainly well featured in the pages of Genetics (for good reason), though I think it's actually his wife, Deborah Charlesworth, who is more well known for working on the population genetics of plants.

      Delete
    2. Hey, they publish together quite often.

      Delete
  7. The big point is that a historical error in biological origins wass always speculative and did not have biologicial scientific evidence.
    Indeed I find PE is ignored but its only contribution was proving the fossil record did not show what Darwin predicted. So they had to imagine episodes of a change in a poulation happening quick and then sticking around to allow the odds of fossilization.
    however evolutionists realized this was admitting to a important flaw in claimed evidence for evolution by way of fossils. so they rejected PE. So why is Gould relevant then? He is not if PE is not accepted. Getting on a Simpson episode will not do it.
    Anyways also here is said micro evolution DOES NOT equal macro evolution. FINALLY the line of reasoning is being seen as unreasonable.
    More anyways. I say one is watching the rapid(evolving? ) demnise of old time evolutionism in our time. Nobody is proving anything even in classification of words which is a major detain in science.
    can modern iD/YEC creationism take credit for putting the stress on evolutionary biologys main tenets?

    ReplyDelete
    Replies
    1. Nobody is proving anything even in classification of words which is a major detain in science.

      I just want to say that this is Byers at the peak of his form.

      Delete
    2. Hi Robert Byers!

      “The big point is that a historical error in biological origins wass always speculative and did not have biologicial scientific evidence.”

      The big point here is: Much opinion, little idea.


      “Indeed I find PE is ignored but its only contribution was proving the fossil record did not show what Darwin predicted. So they had to imagine episodes of a change in a poulation happening quick and then sticking around to allow the odds of fossilization.”

      The most essential thing that Darwin predicted is that organisms are related to each other. And this is exactly what can be easily detected by means of genetic fingerprinting.


      “however evolutionists realized this was admitting to a important flaw in claimed evidence for evolution by way of fossils. so they rejected PE. So why is Gould relevant then? He is not if PE is not accepted. Getting on a Simpson episode will not do it.”

      For evolutionary evidence it is irrelevant whether PE is true or not. But of course a little conspiracy theory must not be missing with you.





      “Anyways also here is said micro evolution DOES NOT equal macro evolution. FINALLY the line of reasoning is being seen as unreasonable.”

      There is no difference in principle between micro- and macroevolution. There is only a little discrepancy in the view what exactly is to be understood by a gradual course of the evolution. Creationists understand by this the process how a roasted half chicken becomes a chicken.


      “More anyways. I say one is watching the rapid(evolving? ) demnise of old time evolutionism in our time. Nobody is proving anything even in classification of words which is a major detain in science.”

      If you would not constantly confuse wishful thinking with science, you too could see that the correct term here is rather "confirmation"...


      “can modern iD/YEC creationism take credit for putting the stress on evolutionary biologys main tenets?”

      Modern? It may have passed you by, but ID/YEC has been obsolete since 1859 at the latest. And also the Enlightenment is not determined by Neolithic wishful thinking…




      Cheers,

      Lamarck

      Delete
  8. Is there an active field that deals with evolution of all life as an ecosystem ie interacting and not independently? Living things form an obligatory closed network which can not be entered or exited from outside and depend on sourcing organic energy only from other lifeforms (plants excepted). Clearly an explanation to be convincing must include the whole network. The difficulties of doing that are obvious and enormous but should not that fact be acknowledged as a limitation?
    As an example speculation about Covid-19 and seasons struck me as being too simple. Should the state of virus's other hosts be considered?
    Poor Huinca got beat up but his question was not answered (he did invite some trouble).

    ReplyDelete
    Replies
    1. This is studied a lot. Studies of two or more species that evolve in ways that affect each other are called studies of coevolution. Obviously the more species you study simultaneously the harder it is -- you can't just wave your hand and say that we have to study all species simultaneously. But you weren't going to do that, were you? (I guess I missed the underlying sensible question Huinca asked, what with all Huinca's loud uninformed declarations).

      Delete
    2. I should add that it is not precisely known what the other hosts of the virus might be. That is of great interest but they don't know yet.

      Delete
    3. I have zero expertise in evolutionary biology but I can tell black from white and conceptual understanding of the current state of knowledge suffices for me. Is it incorrect (per textbook) that viruses infect all life forms and that bacteria has the longest common history and commonly are infected suggesting that viruses might be also older than other critters? Is it hand waving to ask if evolutionary bounds can be hypothesised?
      The nature of the living network i.e. possibly zero sum seems relevant to me and definitely does not appear in pop science (compared to say cosmology say). So does that topic get or got raised? I ask b/c I don't know research literature and don't plan to. This forum might educate me on the cheap.

      Delete
    4. Hi Morris!

      “I have zero expertise in evolutionary biology but I can tell black from white and conceptual understanding of the current state of knowledge suffices for me.”

      There is no shame in being ignorant. It is only a shame not to risk error.


      “Is it incorrect (per textbook) that viruses infect all life forms and that bacteria has the longest common history and commonly are infected suggesting that viruses might be also older than other critters? Is it hand waving to ask if evolutionary bounds can be hypothesised?

      The origin of the viruses is not known. However, since viruses do not have a metabolism, I hypothesize a parasitic origin.


      “The nature of the living network i.e. possibly zero sum seems relevant to me and definitely does not appear in pop science (compared to say cosmology say). So does that topic get or got raised? I ask b/c I don't know research literature and don't plan to. This forum might educate me on the cheap.”

      While we're at it: Read Gould’s “The Panda's Thumb”.




      “I ask b/c I don't know research literature and don't plan to. This forum might educate me on the cheap.”


      There is no shame in being ignorant. It is only a shame not to risk error.




      Cheers,

      Lamarck

      Delete
  9. Hi Larry Moran,

    some support on this (1):

    (i) “The Modern Synthesis is the version of evolutionary theory [...]”

    A scientific theory is the best that can be had in the natural sciences. This can experience a hypothetical extension as a consequence of the proving (e.g. “Copenhagen interpretation of quantum mechanics”) and, if necessary, experiences its subordinate continuance as a boundary condition of an extended theory (e.g. “classical mechanics vs. QM”).

    In short: For the systematic explanation of nature there are hypotheses, which tend to infinity according to their number; but to a definition area either only one or no theory fits.

    Darwinism, strictly speaking (Darwin in the diction of the 6th ed.), does not represent a theory of evolution, but a theory of selection, which was even hypothetically extended by Lamarckism.


    (ii) “The general idea was to merge Dawrin's view of natural selection with the relatively new field of population genetics.”

    Evolution exists even without population genetics… ;-)

    The STE was the surprising result of the evolutionary war of selectionists vs. mutationists. In essence: the mutationists accused the selectionists that selection only selects but does not provide variability and, conversely, the selectionists criticized the mutationists that mutations only occur within a given framework and that the conditions for this framework are not variable. However, the changed view of the role of mutation in the evolutionary process by both groups brought the breakthrough.


    (iii) “In Gould's classic 1980 paper on "Is a new and general theory of evolution emerging?" (Gould, 1980), he argues that the current view of the Modern Synthesis is defined by scientists like Ernst Mayr [...]”

    That was funny: Gould tries to attack the STE with a “begging the question” paper via straw man argument to Mayr and has accomplished nothing more than defending the STE to Mayr (The one who thought he was the STE ;-) )! Okay, Gould should have just tried to falsify the STE. And that would be Huxley (1942).


    (iv) “If this is the correct view of the Modern Synthesis then it is "effectivly dead" for several reasons. Those reasons are better explained in his Tanner Lecture at Cambridge University (UK) in 1984 (Gould, 1984). He lists three major challenges to the Modern Synthesis.”

    "effectivly dead" ≠ wrong
    "effectivly dead" ≠ "three major challenges"




    Cheers,

    Lamarck

    ReplyDelete
  10. Hi Larry Moran,

    some support on this (2):

    (v) “There are some scientists who think that the Modern Synthesis evolved in the late 1960s to incorporate the fact that random genetic drift is the most common mechanism of evolution. According to these scientists, Neutral Theory, Nearly-Neutral Theory, the Drift-Barrier Hypothesis, Mutationism, and a host of other concepts have been absorbed by the Modern Synthesis so it's still possible to refer to modern evolutionary theory as the Modern Synthesis.”

    Oh dear! ;-)

    "Nothing in Biology Makes Sense Except in the Light of Evolution." Theodosius Dobzhansky first used this phrase in the summer of 1964 at a meeting of the American Society of Zoologists. As president of that society, he gave a long speech about the place of organismal biology in a world increasingly dominated by molecular research. He was responding to comments by colleagues who referred to anything that was not molecular biology as "bird watching" or "butterfly collecting".

    Since evolution is directed towards the preservation of the germ line, it cannot be seen at the level of molecular biology. But molecular biology is the level where chance enters the system.


    (vi) “This is a complex issue made even more complex by the fact that Neutral Theory and the role of random genetic drift are not well-understood by most biologists, even by evolutionary biologists who deal mostly with living species.”

    The "Neutral Theory" is more precisely a hypothesis, which allegedly strives to extend the STE [sic!]: After all, the concepts of mutation & selection are not dispensed with here, either. And why should it be a problem for an adaptationist to take mutations with neutral effects or gene drift as forms of adaptation?


    (vii) “[Hughes] The philosopher Daniel Dennett, in his book "Darwin’s Dangerous Idea," proposes that Darwin’s key (and “dangerous”) insight was that evolution is an “algorithmic process." By “algorithmic,” one gathers that Dennett means essentially deterministic. [...] Rather, one might suggest that the truly new idea in evolutionary biology is that of Kimura (building on the work of Sewall Wright), which along with Heisenberg’s Uncertainty Principle and Gödel’s proof of the incompleteness of mathematics, formed part of a Twentieth Century revolution in thought that for the first time revealed the universe as non-algorithmic.”

    The dangerous idea is: they are changeable.

    And no idea how Hughes deduces a non-algorithmic universe from Heisenberg and Gödel (BTW: Determinism ≠ Algorithmic | Gödel = "formally undecidable propositions"). Helpful Keywords: (a) computability theory, (b) evolutionary algorithm (EA).




    Cheers,

    Lamarck

    ReplyDelete
  11. Hi Larry Moran,

    I would like to hope that Arlin Soltzfus has finally learned something, but I am surprised why you quote such prose from 2013.

    “[AS] To know what the Modern Synthesis means, you actually have to do a research project that takes years. That sucks. In an ideal world, what the "Modern Synthesis" means would be clearer. But it isn't. I could explain it in a few sentences, but you wouldn't believe me because the explanation has to come with a huge justification.”

    Hic Rhodus, hic salta! Natural science does not succeed by excuses and apologies, but by intellectual work. This requires inspiration and perspiration.

    On the subject: As a result of theory-guided observation, the discovery of selection and mutation as a unified theory led to the formation of a model for STE:

    STE := Mutation ∩ Selektion

    Thus, the STE actually has the status of a scientific theory. And there is no way to get around this without a successful attempt to refute the STE.


    “[AS] The reason that so much justification is needed is that there are droves of scientists who-- for reasons that I can't fathom -- imagine they are doing the right thing by defending the idea that the Modern Synthesis covers whatever we think today, without bothering to consider that proposition skeptically, as a hypothesis.”

    STE is also subject to evolution in that its basic propositions {mutation, selection, mutation ∩ selection} lead to further constructs. Historically, the most important insight in this respect is the understanding of the result of an evolutionary process as adaptation:

    n (mutation | selection) → n’ (adaptation)


    “[AS] In fact, the mainstream of evolutionary thinking today includes views that were considered "non-Darwinian" and "anti-Darwinian" a century ago, such as the view that evolution depends frequently on new mutations, or the view that selection is not creative but merely sorts out pre-existing genetic varieties.”

    The main problem is rather the ignorance about why STE is actually about. Obviously nowadays everybody believes to be able to play the Trump opposite evolution or quantum mechanics. Darwin himself could not open up the phenomenon mutation yet; therefore it is understandable that he obviously understood selection as the creative process via the detour of Lamarckism. There was nothing else for him.

    Ernst Mayr as Darwin's interior architect has vehemently resisted not to speak of the Darwinian theory, but to keep ready the formulation "Darwinism" also for the STE. Then those writings which expect a new Darwin as a savior. Or those that rant about "negative" and "positive" selection as if there were no peer review...




    Cheers,

    Lamarck

    ReplyDelete
  12. Curious to know what Arlin Stoltzfus thinks of this article: https://academic.oup.com/mbe/article/38/1/181/5893485

    ReplyDelete
    Replies
    1. Hi judmarc!

      And I'm curious why you mention this article of all things. Let's look at the title:

      “Are Nonsynonymous Transversions Generally More Deleterious than Nonsynonymous Transitions?”

      It is bad style to make the title of a paper in clickbaiting form. That should be left to the yellow press. There is a certain bias in this, because a "no" is probably not desired here. And why generally, but not specifically? Even the word "harmful" is not necessarily value-free: harmful to whom or what? And according to the title, something should always be harmful here, thus a different degree of degeneration is meant. Whoever dies earlier is dead longer? And what about the null hypothesis that it is simply insane to look at Ts vs. Tv in this way?

      In the text itself, the authors feel compelled to introduce a correction factor η from an unequal distribution, the meaningfulness of which does not quite make sense to me.

      Just as little as natural selection should succeed in leading to a "fixation" here. The corresponding relation here is also hardly 0.5 - why no Gaussian normal distribution curve in homologous (!) sequence regions?

      And what is to show that what the authors regard as an "equation" is in any way true? Perhaps the authors might also apply their model to the number of letters of the bases (= 1x8, 3x7) or in the binary translation of the sequence (= I O)?!

      ”If you can’t stand algebra, keep out of evolutionary biology.” (John Maynard Smith)




      Cheers,

      Lamarck

      Delete