Let me summarize my last horrible send in a line: "Traits are predictive of reproductive success, and reproductive success is the amplifier or attenuator of trait frequencies."
I don’t see any argument that the above sentence is tautological. And I don’t hear anybody serious making any other claim than the above sentence. My apologies to you all for thisAM…. Eric > On Mar 30, 2026, at 6:53, Santafe <[email protected]> wrote: > > I was on the point of trying to answer Nick a few days ago, while also > acknowledging that since I haven’t had time to read his paper, I should keep > it short. > > It is helpful that EricC has posted in the meantime, because I often believe > I can understand what he means by something, whereas with Nick I often read > things that seem kinda familiar, but then I find some sentence that Nick > writes following a “therefore”, and I am baffled by what logic he thinks that > follows from, making me realize I probably didn’t understand what he > “actually meant” by the earlier sentences either. > > But I will try a short in-line here, with EricC’s version, which is what I > was guessing Nick might have meant a few days ago when he said: > >> This literature you cite often fails to make a distinction between evolution >> as a theory and the theory that explains evolution. Evolution as a theory >> holds that organisms have descended through the ages they have become >> modified to the circumstances of their existence. It is a thesis about the >> causes of descent with modification. Natural selection is a theory offered >> in explanation of that pattern of descent. The literature you describe has >> often fused these two metaphors into one and therefore is fundamentally >> unfalsifiable as a theory that explains evolution. > > Here I was completely mystified what argument Nick understood himself to be > making. Particularly referring to “the literature I cite”, since I sent him > George Price’s The Nature of Selection, which (in the actual print of the > article) says nothing of the kind. > > Put aside that I couldn’t track what the “two” were, or in what sense either > was a “metaphor”, other than that Nick labels them (and all other words; man > with a hammer) as such. > > Anyway, moving on as promised: > >> On Mar 30, 2026, at 0:41, Eric Charles <[email protected]> >> wrote: >> >> I think this (EricS's reply) speaks to the "formalism" issue, and the value >> of the "flavor text". >> >> One of the big problems in evolutionary theory over the last century came >> from the desire for a very particular type of formalism, in which terms are >> all inter-defined, and as such, statements made within the system can't be >> "wrong" in an empirical sense. The classic example (so Nick and I assert in >> the incipient book) is the equation where s stands for "selection" and W >> is "fitness". This has been in biology textbooks of a certain sort for well >> over half a century, and leads to Dawkins's "Selfish Gene" talk, among other >> things. It's hard to criticize on the surface, but, unfortunately, once you >> do that, you cannot usefully study the relationship between fitness and >> selection, because that-they-are-related becomes a truism! > > I _would_ have asked Nick: "What do you mean: is it that the sentence > `adaptedness is an outcome of natural selection' is a tautology, amounting to > nothing more than `fit are the fit'?” I was guessing that might have been > Nick’s meaning, and it sounds like EricC’s meaning here. > > I will take your word for the presence of bad writing and nonsense in > evolutionary textbooks a century ago (probably today, too; the ability of > many scientists to render coherent logic in ordinary English is often not > something to be proud of). And I think I can remember somebody with a > biology degree (so journals are required to publish him), who writes > something like this (was it Pigliucci? If not, I apologize to him for > bringing in his name.) > > But if that is the complaint, it seems to me that that ship had sailed > already with Fisher, though he was so cryptic and imperious in his writing > and his personal style, that it had to wait 40 years for George Price to > explain to the rest of the community what Fisher was saying (and per Glen, > much more importantly, _doing_). Steve Frank has written fairly well on > this; or at least, that is where I got it. (I don’t know which of a > half-dozen papers might be the cleanest source to recommend here.) In any > case, if people didn’t know it had sailed in 1930 or 1958, they certainly > should have known it had sailed by 1972 or 1990 (when Frank found Price’s > 1972 manuscript and published it). de facto, most of the working literature > that has content already makes use of its having sailed, even if they don’t > remark on it, because they use Price Equations as accounting identifies > (among other organizing systems). > > If one is going to assert that there is nothing but tautology in what > population geneticists compute, and therefore they don’t ever predict > anything — a tautology can’t — then I would say that requires ignoring all > the main content of what one is reading in a very large number of papers. > There is an entire causal/predictive structure, and it can very much be wrong > in its imputations. Often, the sources of being wrong can come from things > biologists don’t front as important elements of cause, where I argue they > should, so the things that are wrong can also be interesting. > > What then am I claiming is the non-tautological content, which is there over > and over and over in tons of papers, which Fisher gestured at unhelpfully in > English, but partly did a very important thing with in math, which Steve > Frank acceptably describes, and which Price made didactic? > > 1. First, obviously, we get rid of horoscope-style and Humpty-Dumpty-style > language. We know that “fitness” can’t be doing much work in a causal > account if all it means is “I look at them, and they seem to be happy”, or if > it is meant to be a synonym for the even worse attributive: “design”. > (Remember the important part of the Vampire lore: they have to be invited > in!) We have to actually say _what we mean a predictive theory to be > predicting_. So the attempt to formalize fitness as “reproductive success, > absolute or relative, according to parent type”, is the declaration of the > observable to be the anchor for empiricism. If you like, the “instrument” > that is to be employed. > > 1a. Now, declaring an observable can’t in itself be “wrong” in Popper’s > sense, because it isn’t a logical conclusion. What it can be, however, is > incoherent, and thus a gesture at a definition, which can’t ever be made into > an actual definition. This is the important thing that Fisher did correctly > and explained horribly: making the point that “fitness” must be formalized as > a summary statistic (that’s a technical term, not a metaphor!) of your > high-dimensional observable. The question of when you are _even saying > anything_ turns on when your summary statistic is coherently definable. > Wherever it is coherently defined, it _cannot_ be “falsifiable”, because now > we clearly have a definition that is a completely different kind of thing > than a putative derived conclusion. > > 1b. Next, since heredity plays out in diverse ways in different groups, > summary statistics defined for one won’t generally be defined for others. > Fisher, being a King, in many of the worst senses, and being out to capture > territory (negatively spun) and solve prediction problems (positively spun), > defined a variety of summary statistics from histories that are sequences of > population states connected through reproduction. They aren’t all the same, > and they are not all capable of carrying the same “meanings”. (I’ll get to > what that word means in a moment.) > > 1c. For objects that are suitably described as “replicators” (technical > term, not metaphor!), there is a fitness summary statistic that can also be > assigned as an attribute (just, a marking) of individual organisms. For > organisms that reproduce sexually, or via a variety of complex lifecycles, > the summary statistics that Fisher defined to carry the label “fitness” > _cannot_ be assigned as attributes to any organism, because they are computed > from whole-population counts. So quite apart from what you think you gain by > “marking” an individual organism with an attribute (the bacterial cells > carrying this allele have left 14.32 live daughters per starting cell in 6 > generations in this laboratory instantiation of a population dynamic), for > these sexual-lifecycle summary statistics, you can’t even do that much. > > 1d, Just btw (a thing nobody has any reason to care about), this is where it > is productive to go after Fisher, and the generations that don’t extend > beyond him in their methods. His summary statistics are well-defined, so one > can’t deny that. But they are not _all_ the summary statistics one might > try, and there are others (also well-defined) that can be constructed, which > do a better job of marking organisms and life-stages than Fisher’s fitnesses > do, and support all the same Price-like decompositions. That’s the kind of > thing I do. > > 2. So at the end of all the “1” points above, we have an actual observable > that we have committed to, and that we intend some “theory” to explain or > predict in some way. The whole content of a predictive theory is the > assertion that organisms have attributes in the here-and-now (variously > termed “traits”), which support prediction of the distributions of our > fitness summary statistics as time unfolds. Again, those attributes aren’t > vague gestures like “seems to be doing well”; they should be things one can > commit to somehow: it is dark or light in color; it has softer or harder > shells or teeth or claws; etc. > > 2a. Geneticists try to capture the idea that traits in the here-and-now are > predictive of fitnesses as realized histories unfold, by defining sample > estimators for those dependencies in the form of regressions. Again, if a > regression is defined, there can’t be anything “true” or “false” about it; it > is just a definition. > > 3. The Evolutionists, for some time, have built up terminology around all > this. Samir Okasha’s book uses it (among other things) as a skeleton. I > don’t enjoy the way they say it, but if one is trying to follow their > arguments, the terms are enough to do that. The summary-statistic definition > of the observable is what they call “realized fitness”, and the regression > model on traits in the here-and-now is what they call the “propensity > interpretation”. Yuck; but don’t shoot the messenger. I probably wouldn’t > have coined those terms. > > 3a. It seems pretty inescapable to me that realized fitness and a regression > model on traits cannot be tautologically related, as one requires diachronic > observation even to assign, while the other is assignable (for any fixed > choice of regression coefficients) from a population state at a single time. > (It treats the population composition as a Markov state.) > > 3b. Note that EricC’s s = 1-W above never entered any of what I said. If a > selection coefficient is defined in some way as an algebraic function of > offspring numbers, that is just a layer of notation. The existence of both > realized values W (convertible to realized values s), and model-predicted > expectations for W, derived from model-incorporated coefficients s, means > that the algebra isn’t meant to do other than convenience work _within_ > either layer, and the causal argument concerns the fitting of models to > sample data. If textbook writers render this reality badly, then fine: go > after them. But the flu designers who estimate what should go into an annual > vaccine don’t deserve to be tarred with that brush. > > 4. Finally we can get to the point of what they claim to be doing, and in > competent papers, are doing: Are their regression models predictive, and are > they robust against things that the modeler didn’t notice, but that could > have been included? Hashing out that question is the whole content of the > scientific literature and program. > > 5. Where is conflation an actual hazard in the world I live in, what-exactly > is being conflated, and how might it get something wrong? (So, we have > established falsifiable and in that sense meaningful; now I am talking about > false and thus interesting.) Well, people might identify a trait that they > think confers a tendency to leave more offspring. They might even be right > in their identification. All that is on the “propensity” side. The place > they can err is in supposing that, if they have identified a cause for a > tendency, then they can be assured of an outcome in the same direction (a > wrongful binding of the “propensity” term to the “realized” term), and the > only uncertainty will be the scale of the outcome effect. This is an error I > think evolutionary biologists often do commit in their informal language, > even though the math in any paper wouldn’t let them get away with it, so they > don’t do it there. Others, not even evolutionary biologists, but a kind of > groupie of the biologists from other domains in science, commit this error of > supposition and express it frequently in bar-quality conversation (I have a > certain conversation in a NASA working group in mind as I write this.) The > slip between the cup of propensity, and the lip of realized outcomes, which > biologists don’t account for as fully as I think they should, is illustrated > nicely by magnetism: The “tendency” for spins to align in solid-phase Iron > is identical at all temperatures. However, when the iron is too hot, the > spins don’t macroscopically align “just a little”; rather, they don’t align > macroscopically at all. Then, upon cooling just a little below the critical > temperature, they do macroscopically align, and the alignment rapidly becomes > “a lot” with separation of temperature below the critical value. All this is > the lesson about counting that we learned from thermodynamics. And while the > things being counted in evolution (completed lifecycles) are different from > the things counted in equilibrium thermo (pairs of aligned spins), the > counting argument applies equally well. > > > Anyway…. Sorry for so many words. I hope that I have given enough here to > explain why I am baffled when I hear modern people claim that “adaptation > occurs through natural selection” is “unfalsifiable”. > > The thing about where Dawkins goes wrong is another story, best told by not > quoting his own words, because he is such a rhetorician (even though his > earlier work suggests that he is capable of arguing properly). But it > branches out of the points above, just on the point of mis-representing > summary statistics that cannot be object-attributes, as if they were object > attributes, and then, having set up that strawman, arguing that the only > recourse is to throw the whole thing out above the level of the gene, and > ignore that all the same problems continue to occur for genes, becoming quite > serious in the deeper past. All that can totally be sorted out; there are no > fatal confusions, and metaphor isn’t tripping up anybody who wants to speak > and argue carefully. > > Eric > > > >
.- .-.. .-.. / ..-. --- --- - . .-. ... / .- .-. . / .-- .-. --- -. --. / ... --- -- . / .- .-. . / ..- ... . ..-. ..- .-.. FRIAM Applied Complexity Group listserv Fridays 9a-12p Friday St. Johns Cafe / Thursdays 9a-12p Zoom https://bit.ly/virtualfriam to (un)subscribe http://redfish.com/mailman/listinfo/friam_redfish.com FRIAM-COMIC http://friam-comic.blogspot.com/ archives: 5/2017 thru present https://redfish.com/pipermail/friam_redfish.com/ 1/2003 thru 6/2021 http://friam.383.s1.nabble.com/
