Talk:Mutationism

to do items

 * The historical section really could use a paragraph focused more on the mutationists and their views (instead of on historians and their disagreements). For instance, the major works of mutationism (presumably) are Bateson 1894, de Vries, 1901-1903; Johannsen's works, Punnett, 1905, 1911, 1915; Morgan 1903, 1916.  There should be a list of these, and what are some of the key points of these works.  References can be found in Stoltzfus & Cable, 2014.
 * Also pretty much everyone associates mutationism with Goldschmidt and his idea of macromutations and hopeful monsters, even though he came later than the first wave of geneticists first called "mutationist". So, there should be a citation of Goldschmidt in here and his "hopeful monster" idea.  It is also perhaps historically important-- due to the influence of Mayr-- that Goldschmidt's book inspired Mayr to write another book as a response.
 * this really should be aligned better with the material in https://en.wikipedia.org/wiki/Saltation_(biology)
 * this really should be aligned better with the material in https://en.wikipedia.org/wiki/The_eclipse_of_Darwinism

Nei, Stoltzfus, and achieving a balanced point of view
Note that Masatoshi Nei seems to be editing this article, adding references to his own work, and statements in his typically opinionated style (e.g., the one about Nei not thinking that codon use biases are important). I have no standing to complain, because I'm also a scientist associated with mutationism. I started editing this article years ago because it was so flagrantly bad. Eventually I began to realize that there was an objectivity and balance issue. The version of the article is clearly not well balanced in the sense that it presents a minority view sympathetically, without other points of view.


 * That is at least partly fixed now. I made sure to present this as a minority view, because if you search PubMed, "mutationism" comes up less than 10 times!  I can only think of a few scientists who have associated themselves with mutationism-- Nei, myself, and Larry Moran who has a blog site popular with scientists.  On the other hand, Nei's book was reviewed at least 4 times for mainstream journals and generally fared well.  I don't know how that compares to other minority views.  It might be useful to make a comparison to the reception of neo-neo-Lamarckism a la Jablonka & Lamb.

It is not entirely clear how to present this material consistent with wikipedia guidelines on objectivity and weight (https://en.wikipedia.org/wiki/Wikipedia:Neutral_point_of_view#Due_and_undue_weight). I think if you asked 100 evolutionary biologists about "mutationism", most would identify it as a dead theory that denies selection and claims that evolution took place by dramatic mutations alone. They would say that it was disproved by population genetics, or by experimental breeding, or by Fisher's 1918 paper. The problem is that, if we are talking about historical mutationism, we should not rely on scientists, but on historians of science. The first generation of historians of evolution were strongly influenced by Mayr and his neo-Darwinian narrative, and seem to take a view much like the scientists, but their view has been under revision for quite a number of years, e.g., by Roll-Hansen, or by Gayon. Provine seems positively bitter about being misled by Mayr, et al. Actually Stoltzfus & Cable argue that a close reading of Provine 1971 subverts his neo-Darwinian narrative and lends support to the view that contemporary evolutionary thinking is more like the thinking of early geneticists than it is like the Modern Synthesis.


 * OK, I have inserted a new version of the section on "historical mutationism" in which I tried to address this issue of objectivity and weight as follows. Some basic facts are presented that all agree on. Darwin's theory focused on continuous variation and blending; Johannsen's experiment was understood by scientists at the time to refute that; de Vries discovered mutation; the Modern Synthesis later triumphed.  Then I say that there is disagreement on the interpretation of these events, and present the "classical" view as opposed to the revisionist view of Roll-Hansen, Gayon and Stoltzfus & Cable.  This could use some more references to the classical position, which can be found in Stoltzfus & Cable.  Dabs (talk) 21:13, 4 August 2014 (UTC)

As to the idea of contemporary mutationism, this is also unclear. I assume that most contemporary scientists are not aware of such a thing. Contemporary scientists exposed to Nei's writing may interpret his view similarly as a neutralist position that denies selection (e.g., ).

One way to get a sense of how contemporary scientists are responding to the notion of mutationism would be to look at reviews of Nei's book published in evolution trade journals by Wagner, Wright and others. There is also Gardner's piece entitled "Darwinism, not mutationism, explains the design of organisms", which is a review of Shapiro's book. This is odd because I don't think Shapiro actually refers to his own view as mutationism. Dabs (talk) 13:37, 18 July 2014 (UTC)


 * I just finished a major rewrite of the "contemporary mutationism" section, including the citations above. It starts out just by establishing that the name "mutationism" is back, along with historic references.  Then it describes what this means.  Then it ends with a short paragraph on the reception of this view by scientists.  Unfortunately there is not much to say.

UV and GC content
I have updated the claim by Singer and Ames that a high G+C content could be selectively advantageous with a new reference to Palmeira et al. (2006) Jean R. Lobry 20:05, 3 January 2007 (UTC)

Question: chromosome change?
I can't find an answer to this question, and thought I would post it here: How do chromosome numbers change? Say a population of a given species, all of which share the same chromosome number, is isolated from the main population. Time goes by. Now the chromosome numbers are different in the two populations. Does that happen? If so, how? By what mechanisms? --Serge 23:48, 6 December 2005 (UTC)

Short answer; Polyploidy. There's a very good book on the subject of genome evolution (including the evolution of chromosome number); The Evolution of the Genome by T. Ryan Gregory. You can google Polyploidy I'm pretty sure you'll find plenty of informations on the subject, mostly for plants. --PhDP 07:03, 24 January 2006 (UTC)

Removal of claimed "nonsense"
I removed the following sentence:

It was also demonstrated that levels of mutation necessary to cause significant evolution were not present in the environment and would cause sterility; e.g., in fruit flies.

This sentence does not make sense and does not make reference to any recognizable facts. It refers to "levels of mutation . . . present in the environment", but mutation is not present in the environment, it is a process within organisms. By referring to sterility and fruit flies, the statement makes it sound like it is based on some specific experimental result. If so, what is the result? What is the reference?


 * Yes. You irradiate fruit flies to produce mutations. It's quicker than waiting for them to happen naturally.  You give them too much juice and they can't get it on.  As for a reference, it's really at the level of common knowledge, but you might try to find something by Thomas Hunt Morgan, probably early 1930s. &mdash; Dunc|&#9786; 17:30, 19 May 2006 (UTC)

Here you are referring to levels of radiation to which the flies are exposed, but the disputed statement refers nonsensically to "levels of mutation . . . in the environment". As I said, mutation is not "in the environment". It is an internal process. Mutation is not the same as damage induced by radiation, oxidation, etc: damage is not heritable, but mutations (by definition) are heritable changes. For instance, a TT photodimer is damage, not a mutation; a broken strand is not heritable, but if error-prone repair of the strand introduces nucleotide changes, this represents a mutation.

But just putting the process of mutation back inside the organisms where it belongs would not fix the flawed logic. What principle of mutationism conflicts with the observation that levels of radiation sufficient to produce artificially high levels of mutation (levels that you admit are unnatural) cause sterility in flies? I see no contradiction. Neither apparently did Thomas Hunt Morgan, the mutationist and founder of genetics whom you cite as a source.


 * I agree with Dabs (who should sign his name using ~&#126;). This part is ambiguous. It shouldn't be removed, but at least clearly explained. -PhDP 02:48, 20 May 2006 (UTC)


 * It makes perfect sense. The frequency of mutations required to cause significant evolution is far more than an organism can sustain, as demonstrated by the fact that if you artificially increase the frequency of mutations to that level, you get sterility.  Now improve the wording, find a reference if you feel you need to, but don't remove it because you can't understand it. &mdash; Dunc|&#9786; 10:17, 20 May 2006 (UTC)


 * To make sense here, this argument would have to relate to mutationism, i.e., the view of De Vries and (in a later form) Bateson, Punnett, Morgan, etc. The argument seems to have three parts: 1) there is some level of mutation L "required to cause significant evolution"; 2) when the level of mutation is increased beyond L, sterility results; and 3) this somehow contradicts mutationism without contradicting other theories that erly on mutation.  You have only addressed #2 (incompletely).  How have you determined the level of mutation "required to cause significant evolution"?  How does it relate to mutationism?  De Vries found *actual cases* in Oenothera in which distinctive true-breeding forms arise in a single step that he called "mutation".  De Vries's theory of evolution invoked this process and subsequent selection (i.e., De Vries was a radical species-selectionist: he doubted that within-species variation and selection could account for adaptation and diversity).  Doesn't that vitiate the argument that the mutation rate is too low in nature?  Later mutationists, such as Punnett and Morgan, did not accept De Vries's view, and invoked "gene mutations" as opposed to the kinds of chromosomal rearrangements common in Oenothera.  However, in neither case is there a requirement for a high rate of parallel mutations to cause a mass conversion of the population from one form to another.  This argument does not belong here, but perhaps in the entry on Ernst Mayr or Straw Man.  --Dabs 12:48, 22 May 2006 (UTC)

Rewrite in progress
This was such a mess, and overlapped so thoroughly with Saltation, that I've gone ahead and boldly merged the materials, and am now rewriting the article to cover the history. Not at all sure we need so much on historiography; and many rough edges remain to be smoothed off, but I hope people will be happy with the progress. Chiswick Chap (talk) 09:08, 9 May 2017 (UTC)


 * When I first saw this after not looking at it for a couple of years, I was shocked at the deterioration and drift. Now that the shock has warn off, I'm inclined to say that this is all about focus.   The good thing about the article in its current form is that it relies primarily on historical work, tries to be even-handed, and tries to cover all the territory.
 * So, I congratulate you on your boldness, but I think you just boldly jumped into a hole. If the article is supposed to be about mutationism, this is a terrible article.  I assume that most people turning to Wikipedia for information on "mutationism" have come here from the evolutionary literature where such things are discussed.  So, they are interested in the development of evolutionary thought, and they want to know something about the non-Darwinian views of de Vries, Bateson, Morgan, Punnett, or the views of Goldschmidt, and their influence.  They will particularly want to know about any views that were influential historically, and they will particularly want to know about any views that are still "in play" in current thinking.   The current version, instead, gives the reader information on "saltationism" going to back to the 19th century.
 * The basis for this choice in the first few words: "Mutationism, known before 1900 as saltationism". THIS IS A HUGE LEAP!   What is the author's basis for saying that "mutationism" was known before 1900 as "saltationism"?  This is saying that mutationism is essentially just saltationism.  But the defining feature of the views of Bateson, et al is that they were going to re-build evolutionary thinking on the basis of the rules of discrete genetics, and the first implication of that was that Mendelian hereditary itself merely maintains, while new variants arise suddenly by discrete events of mutation, which meant that selection was not creative in the way that Darwin imagined.  This argument did not rely on the mutants having large effects, but on being discrete in occurrence and perfectly inherited.  Bateson, et al. tried to build a view from the bottom up, from mechanisms to behavior, rather than previous thinkers who began with presumptions about high-level behavior of evolution and then speculated about mechanisms.   I think this is fairly clear from Gayon, from Stoltzfus & Cable, and other historical sources cited by them.  I don't recall any evidence that Bateson, et al. saw themselves as being part of a saltationist tradition.   Dabs (talk) 19:42, 10 August 2017 (UTC)


 * See my reply to the next item on Conflation. On Bateson's saltationism, see Nicholas Gillham's 2001 "Evolution by Jumps: Francis Galton and William Bateson and the Mechanism of Evolutionary Change" which discusses the matter in detail (ref is in the article). Chiswick Chap (talk) 07:18, 22 August 2017 (UTC)


 * Well, it seems I was basically right after all. Both Bowler and Smocovitis think De Vries's mutationstheorie was saltatory, and given that De Vries thought he was getting new forms that couldn't interbreed with each other (see Mayr's species concept...) by a single "mutation", it's going to be hard to disagree. I'm not going to rush to put the articles together (though it's definitely an available option), but they certainly and necessarily overlap in subject matter, and to a degree in period also: obviously saltation was discussed for many decades before De Vries, but apart from that, M. fits neatly into the saltationist mould. Chiswick Chap (talk) 20:12, 14 September 2017 (UTC)

Possibly incorrect conflation of concepts, saltationism and mutationism
AFAIK saltationism is opposed to gradualism (not "phyletic gradualism", which opposes punctuated equilibrium, both almost unrelated). Meaning that it allows for or affirms a greater role for mutations causing a more drastic phenotypic difference, as opposed evolution being restricted to gradual variation, the sort of mundane additive variation that accounts for the bulk of ordinary variation in living populations. For concrete but hypothetical examples, in the ancestors of whales, mutations that abort completely or much more dramatically the size of the hind legs/"fins", rather than the ordinary minute variation in size; for eyeless animals, mutations that simply abort the development of the eye (or even one eye, as may be the case with the Mexican tetra), versus genes for progressively more minute but normal eyes, over generations, until they finally reach phenotypic nonexistence. "Freaks", as opposed to "normals". And that is regardless of the "size" or whatever genetic aspect of the mutation at the DNA level -- DNA wasn't even known then. And even "mutationism" doesn't refer to "size" of mutations at the genetic level, but is rather about mutation as a "driving force" alongside selection, rather than just providing the "raw material". That is, if some mutations are recurring enough, they will add to the genetic frequencies of such recurring alleles, at least against neutral variation, and possibly even against some negative selection (maladaptive alleles aren't always completely eliminated, and can even be maintained or increase in frequency if they provide some compensatory advantage, such as sickle cell anemia versus malaria), with the end result possibly coupling alleles of other genes to cope with a recurring maladaptive variation. I can't provide references for such definitions right now, but if I'm not mistaken, this series of articles at the Sandwalk blog will corroborate at least the mutationism "versus" selectionism aspect, mutation as a driver of genetic frequencies. — Preceding unsigned comment added by 189.18.92.181 (talk) 19:56, 25 June 2017 (UTC)


 * Hm, this (and the previous thread, which makes a similar point) will need careful attention. I see from the Sandwalk blog by Stoltzfus that "Apropos, the following quotation from Ernst Mayr never fails to make me [Arlin Stoltzfus] laugh: 'The genetic work of the last four decades has refuted mutationism (saltationism) so thoroughly that it is not necessary to repeat once more all the genetic evidence against it.' (Mayr, 1960)". This shows that I was following a tradition which at least included Mayr in equating mutationism and saltationism, so I did have a RS available if I'd wanted it. Obviously, genetics didn't exist before 1900, though the idea of a sudden freak was available long before that, and knowledge of DNA and its coding wasn't available until 1953, long after the early mutationists. Mayr, I now appreciate, had an axe to grind, and Stoltzfus is I think right in arguing that Mayr (and Huxley, and others) was pushing a story that favoured his side (politics with a small p). There is clearly some kind of continuity between saltationism and mutationism, but the story is richer than Mayr would have it. I'll read some more and hope to improve the article stepwise rather than, um, in sudden jumps. I agree with Dabs that one change I made, namely to treat the topic evenly and historically with names, actions, dates and citations is beneficial, not least because it acts to counter what Stoltzfus calls "myths", and what I'd call political story-pushing, or selling a party line. This will take time so please bear with me. All help appreciated. Chiswick Chap (talk) 07:29, 22 August 2017 (UTC)


 * Erm, mutationism is definitely not saltationism. There's kind-of a relationship, insofar as saltationism relies on extreme mutants (Goldschmidt's "hopeful monsters"), but mutationism is not primarily concerned with macromutations. So, to my mind, the opening sentence is entirely off-base. My reading is that mutationism suggests that, instead of particular mutations being favoured by differential organism survival and prospering (i.e. selection), what actually happens is that mutations become dominant in a population via their somehow elevated (and there's the rub) frequency of occurrence. And this does not have anything to do with saltationism. Admittedly, it's difficult to think of mutationism as anything other than absurd given that different organisms will inevitably have different survival and reproduction rates (i.e. selection). Anyway, I feel a rethink is needed here. --P LUMBAGO 13:46, 22 August 2017 (UTC)


 * That's already agreed. I have reverted the redirect of Saltationism so the articles are again separate, and removed purely saltationist material from here. However, macromutationism (enormous sudden jumps) is certainly saltationist, and much early saltationist thinking anticipates mutationism, that mutations can drive evolution. So overlap between the two articles is necessary. When mutationism means that mutations create variation, drive evolution, or simply make it possible, on the other hand, that's not at all saltationist. Mutationism was certainly not absurd in 1909, and the experimental work of the early Mendelian / Mutationist geneticists was valuable. Chiswick Chap (talk) 13:56, 22 August 2017 (UTC)


 * Good. I can see it's already changed quite a bit since I wrote before (of which, the opening sentence is completely different, so my statement above on this might have been confusing). I would agree, incidentally, about the less-absurdness of mutationism at the start of the 20th century - I was thinking of now, when it's actually difficult to articulate mutationism without it sounding rather odd. Cheers, and thanks for the good (and clearly ongoing) work on the article. --P LUMBAGO 15:41, 22 August 2017 (UTC)