Once more unto the breach


I’m preparing to teach genetics again, and as usual, I’m trying to rework some of the lectures, because I don’t care to say the same thing every year. I had one odd thought that I’m probably not going to squeeze into the lectures this year, but thought I’d bounce it off people here.

Evolution and genetics were on parallel tracks in this very interesting period of 1860-1910. While the American Civil War and the Franco-Prussian War and the Boer War might have been distracting most people, biologists had their own obsessions. Charles Darwin published in 1859; Gregor Mendel in 1863. Darwin had immediate popular success, while Mendel was basically ignored and neglected. I was contemplating why the difference was there, and had a random idea.

Darwin started with a phenomenological and largely descriptive foundation, no significant math anywhere in The Origin. Mendel’s brief paper was little more than a mathematical hypothesis, with limited qualitative description — it was just peas, one model system, and the traits weren’t even particularly interesting, except for the fact that their inheritance was so discrete.

Evolution took off fast, and rather erratically. There were so many bad hypotheses built on the framework of natural selection (for instance, all of Haeckel’s work) that by the end of the 19th century, Darwinism (and in this case, that was an appropriate name for it) was fading, and people were finding flaws and poking holes in the idea. The absence of a quantitative basis for analysis was killing evolutionary theory.

Meanwhile, Mendel’s laws of inheritance weren’t getting any attention, but there was all this foundational qualitative work getting done — cell theory was being established, microscopy was taking off (instruments were reaching the physical limits of optics), Weismann had worked out the limitations of cellular inheritance, Sutton and others were publishing all this tantalizing stuff about chromosomes. When 1900 rolled around and Mendel was rediscovered, everyone was primed for his statistical/probabilistic theory of inheritance. We could do math on it!

Also, evolution was rescued by it’s happy marriage to genetics and in particular, population genetics. We could do math on evolution, too!

Everything is better with mathematics, is my conclusion. Except maybe individual success — before 1900, someone could come up with a hot theory and get it named after themselves. Afterwards, there’s too much detailed quantitative thinking going on for any one person, and eponymous theories went out of style, being regarded with suspicion, even.

Along comes SMBC to correct me:

OK, OK, it’s not just mathematics, it’s thinking precisely. But isn’t that what math is? How do you think precisely without the application of math and statistics and quantitative reasoning?

Comments

  1. says

    The real key thought to get out of the SMBC cartoon above is that it is quite frequently math abuse to apply math to imprecise things. We’d greatly mitigate the techbro / libertarian douchebag / nazi atheist problem if we could get miscreants to understand this.

  2. says

    I think it is more that science deals with discrete observations that then require a continuous relationship to explain as a phenomenon. Math simply provides a fundamental relationship that gives a continuous means of organizing the discrete observations so they can be predicted.

  3. justawriter says

    There is also a huge difference in the circumstances of the two men. By 1860 Darwin had been a member of the Royal Society for more than 20 years, having been elected at 29. He was the author of a long series of well received natural history books based on his time on the Beagle and observations in Britain, on topics from coral atolls to worms. Mendel was a studious monk who had failed his exams to become a high school teacher and published his work in a local science society journal. His religious duties increased after he became abbot of the monastery interrupting any followup research. It is entirely possible that no one capable of understanding the importance of his discovery ever saw his paper while Darwin already had an influential audience waiting for his next publication.

  4. seachange says

    Going further than John Watts #4

    Mathematics is in many ways its own language. Philosophers often talk about how natural languages suck because they are ambiguous and sloppily grammared etc. and try to create new ones. They fail. The Klingon-language does not fail. Because in order to do the main survival thing for humans, you need the slop. People grow up learning to communicate that way in which there are five definitions for a word that sounds like ‘right’ (rite, wright).

    People who think precisely -and these are not philosophers- do math and suddenly there’s new symbology that always means the same thing all the time. If you’re brain is not set to understand a new code-system this is a challenge. If it is, it is a lesser one. But that’s the thing: talking precisely to people gets you into godsdamned trouble. Science requires standing on the shoulders of giants, so you need to talk so other people will listen. Surviving day-to-day involves going to the grocery store and not getting your head chopped off by someone who’s better at swinging (hopefully) metaphorical swords at you than you can sharply talk.

    Of course Mendel got ignored.

  5. Rich Woods says

    @John Watts #4:

    German. While that was the commonly used language for scientific communication in Northern Europe at the time, it does seem unlikely that a journal published in a distant, small regional capital ever made its way to the Royal Society or to any of the major British universities. Even as Darwin’s ideas spread in the 1860s and 70s no-one in Brno seems to have considered a connection with Mendel’s work, and as time went on it was increasingly less likely that anyone who had read it would remember it.

  6. Bad Bart says

    I’ve become known as the language police in several companies–imprecise, “we all know what we mean”, language has caused too many production delays. It is particularly bad in biotech where multiple domains have to come together–and while it is usually clear whether we are talking about the pathologist’s “sample”, the instrument manufacturer’s “sample”, or the statistician’s “sample”, that isn’t always true.

    More than once I’ve seen heated arguments come to quick and amicable resolution once those involved realized they weren’t actually talking about the same problem.

  7. cheerfulcharlie says

    Evolution was something that had been debated long before Darwin and Wallace came up with natural selection and sexual selection. Everyone knew evolution was occurring but was puzzled over the exact mechanism. Part of the key to that puzzle was discovery of geology of the immense age of the planet. Mendel was doing something new and was not well known in the evolution debate, and was published in an obscure journal.

  8. Pierce R. Butler says

    Rich Woods @ # 7: … it does seem unlikely that a journal published in a distant, small regional capital ever made its way to the Royal Society or to any of the major British universities.

    Can’t recall just where I read this, but apparently a copy of the journal in which Mendel published was found in Darwin’s library.

    Printing at that time entailed long sheets of continuous paper, and readers had to use scissors or knives to separate the pages. Though Darwin could read German in a limited way, he had not applied any such tool to this particular publication, so we know he did not read it.

    Imagine how scientific history might have changed if he had …

  9. pilgham says

    On precision and math, I thought of Kepler and Brahe, where Brahe provided the precision and Kepler the math. (I haven’t actually read the post yet, just looked at the pictures. I think that causes more problems…)

  10. says

      Dear PZ, First of all, I know you are diligent and like to review your work and refine it. But, don’t run yourself ragged trying for ‘fresh content’ (that’s just a stupid pop culture idea). Remember, only those who are repeating your classes will know if it is the same as last year.
      You said, ‘Everything is better with mathematics’. I agree that is generally true. However, That just doesn’t add up (every time). There are ‘artistic’ endeavors that are not precise or mathematical and yet they can still be masterpieces.
      No miracles! And, it’s more than just thinking precisely, it must also be rational, or you are wandering back into the swamp of miracles again. Don’t create an endless ‘logic loop’.
      And, to mix topics, we ‘observe’ that the tRUMP is trying to make the united states ’empirical’ again. And, that was a disaster the last time it was tried.

    Stay sane, PZ.

  11. says

    Oh, and by the way, I notice there are a lot of ‘new faces’ in the comments. I don’t have the data, but it seems you are gaining quite a following (and that is appropriate). Just don’t go crazy for followers and turn this blog into another disgusting muskrat xhitter.

  12. Hemidactylus says

    @10 Pierce R. Butler

    …apparently a copy of the journal in which Mendel published was found in Darwin’s library.

    https://www.nature.com/articles/s41437-019-0289-9

    Is there any evidence that Darwin read Mendel’s paper, or read about him? This question has been debated for more than 50 years (Vorzimmer 1968), and the short answer is a qualified “no”. Mendel obtained forty offprints of his paper; the fate of only a few is known (Orel 1976, 1996). A rumour purports that an uncut offprint of Mendel’s paper was discovered in Darwin’s collection after his death (for examples see Hennig 2000; Leonard 2005; Fishman 2018), with no credible evidence to support it. It probably arose from the fact that Focke’s (1881) book, Die Pflanzen-Mischlinge (The Plant Hybrids) was in Darwin’s library, with summaries of Mendel’s experiments, yet the pages of these summaries remain uncut. The fact that Darwin owned this book probably morphed into the rumour that he had an uncut offprint of Mendel’s paper, when in reality he had an uncut reference to it, acquired little more than a year before his death (Fairbanks and Rytting 2001).

    Fairbanks shows that Mendel on the other hand may have had some familiarity with Darwin’s views.

    See too: https://www.pnas.org/doi/10.1073/pnas.2122144119

    Renowned Darwin biographer Janet Browne and Andrew Berry write:

    As previously mentioned, there is speculation about whether or not Darwin had access to Mendel’s results. There is no evidence to support this… However, what about a paper-mediated meeting of the minds? One scenario suggests that Mendel sent Darwin a copy of his publication, but it remained, its pages uncut, on the shelves of Darwin’s library. Like most anecdotes, this is not as simple as it looks. The story gains added piquancy from the suggestion that Darwin might have failed to appreciate its significance… Some historians have suggested that Mendel sent Darwin a copy in the mail. These claims are impossible to substantiate, although we know that Mendel did distribute 40 copies to European colleagues at his own expense (23). There is no copy of the offprint in the existing Darwin archive (24). Kerner von Marilaun, who had been one of Mendel’s teachers at Vienna University, received one that was evidently unread because the pages are uncut. Interestingly, another copy, now in the Institute of Botany in the University of Amsterdam, is the one that Hugo De Vries read in 1900 (ref. 17, p. 70, and ref. 25).
    What is easier to substantiate is that in 1881, Darwin did have access to a comprehensive published account of research into hybridity in which Mendel’s work was mentioned. This book (26), by Wilhelm Olbers Focke (1881), was a useful compendium of works on hybridization. Darwin lent his copy to George Romanes who was then writing an article on hybridism for the ninth edition of the Encyclopedia Britannica (27, 28). Focke remains in Darwin’s library, preserved in Cambridge, United Kingdom. Tellingly, this too has never been read because the pages retain the original uncut edges (29). Mendel’s work was literally a closed book to Darwin.

  13. Hemidactylus says

    So what about Mendel’s approach to Darwin’s work? From Berry and Browne in PNAS above:

    If Mendel’s work was a closed book to Darwin, the reverse was certainly not true (29). Mendel read Darwin’s Origin of Species in the second German edition of 1863 and there are suggestions that his later experiments may have been set up to explore Darwin’s evolutionary proposals more generally in the manner of Karl F. Gaertner or Charles Naudin, both of whom were cited by Darwin as fine experimentalists in plant hybridization (30).

    So Darwin was ignorant of Mendel, yet Darwin was percolating through Mendel’s brain? Fairbanks from the Nature link above:

    Darwin’s writings directly influenced Mendel’s classic 1866 paper, and his letters to Nägeli…In his final letter to Nägeli, Mendel proposed a Darwinian scenario for natural selection using the same German term for “struggle for existence” as in his copies of Darwin’s books…The image that emerges of Mendel is of a meticulous scientist who accepted the tenets of Darwinian evolution, while privately pinpointing aspects of Darwin’s views of inheritance that were not supported by Mendel’s own experiments.

    And so on…

  14. Hemidactylus says

    Fairbanks really pushes the idea of Darwin’s covert then overt influence on Mendel. He was involved in a Darwinized translation of Mendel’s work that leans toward this view. I don’t have the background to critically evaluate such an idea, but I will link it here:
    https://pmc.ncbi.nlm.nih.gov/articles/PMC5068835/

    Abstract
    Gregor Mendel’s classic paper, Versuche über Pflanzen-Hybriden (Experiments on Plant Hybrids), was published in 1866, hence 2016 is its sesquicentennial. Mendel completed his experiments in 1863 and shortly thereafter began compiling the results and writing his paper, which he presented in meetings of the Natural Science Society in Brünn in February and March of 1865. Mendel owned a personal copy of Darwin’s Origin of Species, a German translation published in 1863, and it contains his marginalia. Its publication date indicates that Mendel’s study of Darwin’s book could have had no influence while he was conducting his experiments but its publication date coincided with the period of time when he was preparing his paper, making it possible that Darwin’s writings influenced Mendel’s interpretations and theory. Based on this premise, we prepared a Darwinized English translation of Mendel’s paper by comparing German terms Mendel employed with the same terms in the German translation of Origin of Species in his possession, then using Darwin’s counterpart English words and phrases as much as possible in our translation. We found a substantially higher use of these terms in the final two (10th and 11th) sections of Mendel’s paper, particularly in one key paragraph, where Mendel reflects on evolutionary issues, providing strong evidence of Darwin’s influence on Mendel.

    But then B. E. Bishop:
    https://academic.oup.com/jhered/article-abstract/87/3/205/908553

    Abstract
    Although the past decade or so has seen a resurgence of interest in Mendel’s role in the origin of genetic theory, only one writer, L. A. Callender (1988), has concluded that Mendel was opposed to evolution. Yet careful scrutiny of Mendel’s Pisum paper, published in 1866, and of the time and circumstances in which it appeared suggests not only that it is antievolutlonary in content, but also that it was specifically written in contradiction of Darwin’s book The Origin of Species, published in 1859, and that Mendel’s and Darwin’s theories, the two theories which were united in the 1940s to form the modern synthesis, are completely antithetical.

    So…

  15. silvrhalide says

    Darwin was wealthy. Mendel was not.
    It’s easy to promote a theory or one’s scientific work when you don’t actually have to work for a living and equally important, your wealth allows you access to the people who will be interested in your work and who might actually use it.

    Gregor Mendel was a monk who did not come from a wealthy family. Even though the abbey provided, everyone in it had to work.

    Ask anyone who has ever poured blood, sweat & tears into a passion project how much time it took. The ones who have to work for a living usually have to take far longer to get the thing done.

  16. says

    Meh. Everyone was rushing to stamp their own interpretation of evolution on Darwin, so I don’t see much point in arguing whether any old 19th century guy was pro or con.

  17. Hemidactylus says

    Meh? Meh?

    Mendel wasn’t just “any old 19th century guy” per any pro or con views he had on Darwin. There are far worse ways to spill too much ink than reflecting on Darwin influencing Mendel, since the opposite direction is clearly off limits.

  18. flex says

    Okay, how about a parallel take on it?

    Discus how Boolean mathematics was originally designed by George Boole in 1854, but was considered more of a curiosity rather than having practical uses, although some famous people played around with it. At least until Claude Shannon realized it had a real-world application in 1937 for optimizing telephone switching relays. (Note: I just read this on wiki. It was new to me but relevant. Of course I know who Shannon is, but I didn’t realize his first suggested use of boolean logic was on telephone relays.)

    The lesson is that sometimes the math has already been created, but until science or technology develops to the point where the math is useful, it may just remain buried in technical papers. Innovation does not occur because a lone, rogue, scientist is working on “Things Man Was Not Meant to Know!”, but because the work of many people collaborate. Sometimes whole groups of people head down the wrong path (remember N-Rays?). But, because science, all science, is collaborative, the process will eventually reach an greater understanding of the universe.

    There are probably other examples beyond Boole. Maybe other commenters can think of some?

  19. Erp says

    “Though Darwin could read German in a limited way, he had not applied any such tool to this particular publication, so we know he did not read it.”

    Apparently quite limited. He seems to have depended on his wife, Emma, for some of his German translation (women of her class were typically educated in modern languages while their brothers were taught the classical languages necessary for admission to Oxford/Cambridge). Their daughter wrote “My father often said that where she [Emma] failed in making out and translating a sentence for him in German, a non-scientific German would generally also fail.” (EMMA DARWIN: A Century of Family Letters https://darwin-online.org.uk/converted/published/1904_EmmaDarwin_F1552/1904_EmmaDarwin_F1552.1.html) The daughter also wrote that Emma knew French well and also a fair amount of German and Italian.

  20. says

    fishy, that bothered me as well, as I remember an aphorism that inspiration without technique yields incompetence, but technique without inspiration yields sterility. You do not usually find artists completely lacking in one or the other, but find them with qualities of both. (And in my own case, one of the harshest criticisms I remember receiving as a young student was along the lines that my technical skills were secure but where were the big ideas?)

  21. voidseraph says

    “Talking precisely about precise things” is more plausibly a description of logic than it is of mathematics. Mathematics, the axioms of set theory, the structure provided by the principle of induction are much more substantive than simple logical precision.

  22. rietpluim says

    Sorry to burst your bubble but math does not work more often than it does.
    You can keep adding one apple to one orange but it won’t make two pears.
    One plus one equals two only in very specific conditions.

  23. Jack Krebs says

    Nice interesting post, I think. And to rietplum, isn’t being clear about the specific condition for which 1+ 1 = 2 an example of the precise thinking we need to do when we apply math?

  24. rietpluim says

    @Jack Krebs #26 – There are no such conditions in math itself. In math, one plus one equals two unconditionally.
     
    Of course, I posted #25 more or less jokingly, but the point is that math is not applicable in different fields of study by some sort of miracle. We have to do something to make it applicable. People are forgetting that when they say it’s astonishing how it just works in so many areas.

  25. Rob Grigjanis says

    Maths is like sex. If you know how, it’s much more fun doing it than talking about it.

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