Why we don’t want another “Synthesis”
High-level debates in evolutionary biology often treat the Modern Synthesis as a framework of population genetics, or as an intellectual lineage with a changing distribution of beliefs. Unfortunately, these flexible notions, used to negotiate decades of innovations, are now thoroughly detached from their historical roots in the original Modern Synthesis (OMS), a falsifiable scientific theory.
The OMS held that evolution can be adequately understood as a process of smooth adaptive change by shifting the frequencies of small-effect alleles at many loci simultaneously, without the direct involvement of new mutations. This shifting gene frequencies theory was designed to support a Darwinian view in which the course of evolution is governed by selection, and to exclude a mutation-driven view in which the timing and character of evolutionary change may reflect the timing and character of events of mutation. The OMS is not the foundation of current thinking, but a special case of a broader conception that includes (among other things) a mutation-driven view introduced by biochemists in the 1960s, and now widely invoked. This innovation is evident in mathematical models relating the rate of evolution directly to the rate of mutation, which emerged in 1969, and now represent a major branch of theory with many applications. In evo-devo, mutationist thinking is reflected by a concern for the “arrival of the fittest”. Though evolutionary biology is not governed by any master theory, and incorporates views excluded from the OMS, the recognition of these changes has been hindered by woolly conceptions of theories, and by historical accounts, common in the evolutionary literature, that misrepresent the disputes that defined the OMS.
Read. Discuss.
CharlieM:
The organism doesn’t just pop into existence and proceed to control everything, Charlie. It gets built. Where do the “building instructions” come from? DNA.
CharlieM:
Precisely. So my prescription for you is: More science; less of Steiner, Barfield, Talbott, and the other wooprietors you are so fond of.
Of course it doesn’t just pop into existence. The mother’s fertilised egg makes its way to the uterus where it implants. But at no time from fertilisation on is it not a complete organism and it develops from internal processes with assistance from processes originating in the mother. At all times the development is controlled by the combination of proteins, DNA and the environment, none of these in isolation. (Unless of course you can persuade me otherwise I will continue to accept that as a fact)
Pity your civilised debating skills do not match your name-calling skills. 😉
CharlieM:
So much for your “master controller”, then.
Charlie,
It’s common sense. If you think we should be listening to the science, then you ought to, you know, listen to the science, and not to Steiner, Barfield, Talbott et al.
Yes, I think you’re right about this. And this conviction is, in turn, rooted in a fundamentally theocentric metaphysics & epistemology. It all turns on the idea that the deepest and ultimate explanation of all things is just how God Himself sees the universe. That theocentric conviction in turn lies behind the rise of grand unifying theories in physics and elsewhere.
By contrast, the emphasis on a plurality of partial explanations is much more consistent with an anthropocentric conception of how to do epistemology: that is, think about knowledge and what can be known in terms of our cognitive abilities and inabilities.
Yes, I quite agree and nicely said.
I think that’s the point. Organisms aren’t machines, they are organisms.
CharlieM,
Ah, so that’s how this game is played. How on earth could one ever persuade you otherwise?
Such bald assertion.
https://craftsncoffee.com/2016/02/19/homework-helper-how-to-build-a-3-d-animal-cell-model/
A few drinks. A beautiful woman.
Mung,
Heh. I don’t care enough to spend money or start pimping …
Rumraket:
It isn’t the diversity per se that makes a unifying theory unlikely. After all, physics also encompasses an incredible diversity of phenomena, yet we’re down to two theories — QM and GR — with hopes of unifying the two.
I used to think so, too. But then I started worrying about what is really mean by ‘machine’ in such avowals. I mean, if the idea is that organisms aren’t clocks — well, ok, sure. That’s true.
And yet, consider Maturana and Varela’s autopoiesis (“self-making”) theory. On their account, what’s distinctive of organisms isn’t what they are made of but how they are organized. Their organization is such that the continuous activity of the organism contributes to the continued existence of the organism, e.g. it expends energy in order to get food in order to produce the energy it needs in order to repair, rebuild, expel waste, etc. Or it expends energy in order to synthesize new sources of chemical energy from light energy or heat energy. What the organisms does contributes to the organism’s continued existence.
Why not say that organisms are indeed machines — that is, autopoietic machines? One could stipulate that “machine” excludes autopoietic systems, but what’s the point of that insistence?
I agree.
However, people disagree over the meaning of “machine” and “mechanism”. And it’s a waste of time to engage in semantic arguments.
Beyond Mechanism: Putting Life Back Into Biology p.297
ETA: Most of the chapters in this book offer critical reflections on the neo-Darwinist outlook and work to promote a novel synthesis that is open to a greater degree of inclusivity as well as to a more holistic orientation in the biological sciences.
Oh good. Another synthesis. 🙂
This distinction has been explored at great length throughout the history of what we might call science fiction. The notion of what’s a robot, a clone, an android, a cyborg, etc. etc. is the springboard for endless story plots. And inevitably, the resolution becomes that, at the margin, the two cannot be usefully distinguished.
A closely related plot trope concerns the definition of life – what set of characteristics must all life possess, that “non-living” systems cannot? And here, it turns out that not all living organisms possess every characteristic, and many “non living organisms” possess more of them than some life. Does a self-altering computer program resemble “life” more or less closely than a virus?
If you wade into these waters armed with no more than the conviction that “organisms are not machines” you are quickly revealed as a simpleton.
But there are many sub-branches of physics with very diverse phenomena you can’t really understand in a simple way from the equations of QM or GR.
One example is fluid dynamics, another is meteorology and climatology. Another is geophysics. Ultimately they all deal with phenomena that are “due to” QM and GR, as the phenomena they deal with are “made of” huge ensembles of elementary particules suspended in gravitational fields. But you can’t take away the equations and models from these sub-branches of physics and expect to make sense of the Earth’s atmosphere, oceans, and climate, using quantum mechanics or general relativity.
I think this is the situation we are in with biology and evolution too. There’s probably going to be some set of theories of evolution that deal with their own limited set of manifestations of evolutionary processes.
Rumraket,
That seems right to me. When we don’t even know (yet?) how to replace two incompatible theories of fundamental physics with a single comprehensive theory, and we don’t know how to reduce much of non-fundamental physics to fundamental physics, the prospects are rather dim for reducing any branch of non-physics to physics.
Likewise, within biology, the prospects are rather dim for a single overarching theory of life as such. Even if we did have a good theory of what it is for something to be alive (and I’ve been a cheerleader for autopoiesis for years), that’s not going to be a theory of evolution. And while we have various models of different evolutionary processes, I share your suspicion that a good theory of the evolution of multicellularity (should we ever solve that particular problem) is not going to do the work of a theory of evolution of viruses, etc.
The problem with an extended evolutionary synthesis, I’m finally realized, is that it basically takes all the various mechanisms and processes we’ve discovered, puts them in a big bag along with population genetics, then just crosses out the word “modern” and replaces it with “extended”. I’m beginning to understand why that’s unsatisfying!
That is just preposterous.
You don’t think Darwinain evolution has been used as an answer to philosophical questions for the past 100 years?
Now suddenly they are separate issues?
Virtually all of science informs philosophy. Can you have philosophy without an understanding of science? I think that is essentially impossible.
So when you have a patchwork of theories, and they can’t be combined to give you any coherence of what is happening overall and why, then either the world is complete chaos or your theories or wrong.
And if the world is complete chaos, when would you ever believe in a theory?
Or alternatively, human understandings are incomplete, and likely incorrect here and there, to some extent. The world doesn’t somehow become complete chaos due to partial understandings, devised with careful study and great effort. I think you can understand that if you drop a brick, it will fall — even lacking a solid theory combining GR and QM.
You seem to be saying that theories (proposed explanations tying phenomena to causes) are either perfect or useless. But perfection isn’t the measure of a good explanation, utility usually is.
You see phoodoo, it’s really all about what will sell the most books. Utility.
… which shows that what is being dicussed there is not whether these phenomena should be considered, but only what to call the result.
When I gave my theoretical population genetics class, I used to ask what would be needed to have a predictive theory of evolution. One would need to
1. Know the genotypes of all individuals
2. Know how phenotypes were produced by genotypes, in interaction with environments, including other species. (This means a complete knowledge of developmental biology, neurobiology, and ecology).
3. Know how fitnesses of phenotypes were produced (ecology and behavior).
4. Understand changes in the environment completely.
We are of course far from having those levels of understanding.
Then one could use population genetics to predict the composition of the next generation (but even then, you could not predict what genetic drift would do, so it would only be a stochastic prediction). Unless you could predict details of chromosome movement within cells (which of a pair of chromosomes will be closer to the pole of the cell that will form the gamete).
But actually the same is true of physics, chemistry, and sciences such as geology. Can we precisely predict the meanders of a river, or the exact pattern of inclusion grains in a mineral? Not with the level of understanding we have in practice.
Evolutionary biology is a science, in the same sense that geology is. Calls for precision of prediction ignore the fact that many sciences would be unable to achieve that.
keiths:
Rumraket:
No one is suggesting that we fire all the fluid dynamicists and replace them with QM experts. Or absorb the psychology departments into the departments of physics. As a practical matter, we will always have multiple scientific fields and multiple theories.
The question is about in-principle unification, and again, diversity of phenomena per se is not an obstacle to this sort of unification, as the example of physics shows.
DNA and proteins only operate within the context of the cell and the cell only operates within the context of the complete organism. Please give me a specific example of a stretch of DNA instigating any activity in an organism.
Can you provide an example from Talbott’s writings where you believe he contradicts genuine science?
Exactly.
Talbott:
Kantian Naturalist,
Talbott:
The article he quoted from (17) was this one:
Life after Kant: Natural purposes and the autopoietic foundations of biological individuality by Andreas WeberFrancisco J. Varela.
I don’t have access to it but I have taken this interesting passage from the preview:
Hopefully more biologists will begin to take teleology seriously.
Craig Holdrege
CharlieM,
I still haven’t seen an example where it doesn’t. If one tries the tired old ‘DNA needs proteins to transcribe’ routine, those proteins are themselves transcribed from DNA, and the control of that activity is likewise by means of molecules transcribed from DNA. Of course, there is a broader system, and ‘DNA-centrists’ are hardly blind to the broader picture, but to deny the fundamental role of DNA seems pointless – and, when considering evolution rather than development, positively misleading.
By arguing against my statement,
, with enough evidence to convince me that it’s false.
CharlieM,
As it stands, that is non-controversial. But, you are insisting that there is a level of ultimate control which does not reside in DNA, but ‘somewhere else’. Somewhere vague and hand-wavy (and, I may say, rather specific to animals). I don’t see how one is supposed to address that slightly mystical position with evidence against.
I do get a bit tired of argument-by-other-people’s-words too, I might add. Philosophers are also guilty. As the great evolutionist Sam Sparks once said, “yadda yadda yadda”.
You don’t think the notion of teleology without a designer, is also hand-wavy and mystical?
DNA is basically inert. Take a stretch of DNA and by itself it won’t do much at all.
So with your comment here you are criticising me for saying something that you agree with.
I am not advocating anything mystical. I am saying that the control comes from the level of the individual organism. And here you bring up a good question. What do we consider an individual organism to be? Would you say that a single bacterium or the fruiting body of a fungus is an individual in an equivalent way to an individual human being?
True enough. So can anyone tell us how such an inert substance can be the master controller of anything?
No more or less than the claim that the instructions are in the DNA unless you can show me otherwise.
If DNA contains instructions for making RNA show me where in the DNA those instructions reside.
If RNA contains instructions for making proteins show me where in the RNA those instructions reside.
DNA does not make RNA and RNA does not make proteins. It’s all woo.
As the great Sam Sparks said when asked about the theory of evolution, “woo, woo, woo.” Which, properly interpreted means, what theory of evolution? There are many.
So your students learn from you that we do not have a predictive theory of evolution?
Or do they learn from you that we do have a predictive theory of evolution, but that it’s essentially useless? How pragmatic is that?
CharlieM,
I know that Varela and Weber article quite well. I’ve read it a few times and I’ve been following Varela’s work for a long time (over twenty years, in fact).
This link worked for me: Life after Kant (PDF).
But I’m not sure how relevant that discussion is to the question we were discussing earlier in this thread, which is whether we need a single overarching comprehensive theory of biology (an ‘extended evolutionary synthesis’) or if a patchwork of smaller partial theories (an ‘anti-synthesis’) is sufficient.
phoodoo,
No, that’s hand-wavy and mystical too. I don’t know why we have to shoehorn teleology into the process at all.
Mung,
Fantastic. Molecular biologists were hitherto unaware of this amazing fact.
CharlieM,
Yes – that! You express it one way – that there is an interplay of system components – that, I agree with. But then you say something else – that there is a ‘superior control’. That, I disagree with. It is that latter notion that I have no idea what would disabuse you of.
Mung,
If control resides other than in DNA, indicate where, and how that is inherited.
As I see it, there’s a distinction to be made between teleology as description and teleology as explanation. We can take it as a descriptive truth that organisms are goal-directed and goal-oriented, and that their actions conform to a pattern of “doing x in order to y in order to z . . . ” — where “z” will be, in the vast majority of cases, successful reproduction that tends to contribute to the perpetuation of the existence of that kind of organism (i.e. avoid extinction).
There’s nothing in this conception of teleology that requires that these goals be represented anywhere — neither in the organisms themselves nor in the mind of some Designer — in order to be goals. What the goal is and how the goal is represented are distinct issues.
Organisms can have goals without being able to represent themselves as having goals. But moreover, organisms can have goals without there being anything that represents those organisms as having goals. So there’s no need for any Designer (however intelligent) to play an explanatory role here.
With a firm grip on the distinction between teleology as a descriptive claim and teleology as an explanatory claim, we can recognize that organisms are goal-directed while still inquiring into the causal mechanisms that underpin goal-directed activity (e.g. at the neurophysiological or molecular levels) and also the causal mechanisms that generate goal-directed activity (e.g. evolution).
Mung:
CharlieM:
Asks Charlie, who says this:
So Charlie is comfortable with the idea that this combination is the “master controller”, but uncomfortable with the idea that DNA by itself is. Yet the proteins trace back to the DNA. So we’re left with this “inert substance”, DNA, interacting with the environment (including the intracellular environment).
It’s pure mechanism. No woo required, including of the teleological kind.
From experience, I expect Charlie’s reaction to be:
Kantian Naturalist,
OK, fair enough.
I think it’s complicated. Surely there are philosophers who do make Darwinian evolution central to their re-imagining of what philosophy can do and what kinds of answers make sense. Friedrich Nietzsche and John Dewey are the two “biggest” names who have tried to do that. (Although I don’t want to downplay secondary concerns about how well Nietzsche understood evolution or whether his criticisms of it are cogent.)
But I think that Nietzsche and Dewey have had rather little overall impact.
Certainly not separate! Distinct, yes. Separate, no.
Certainly. That is precisely why I made the point that philosophy and science are complementary. I don’t know why you think you’re arguing against me when you make a point that I already made here.
I don’t see why it has to be such an extreme, all-or-nothing choice.
In any event, my point was only that we don’t need a single, overarching theory in order to do biology. Our institutionalized practices of biological inquiry — in genetics, physiology, ecology, neuroscience, and yes even evolutionary theory — do not need a single overarching theory. In that regard I’m happily on Team Anti-Synthesis. (Much as it pains me as a Hegelian to say that.)
Whether we need a single overarching world-view in order to grapple with the deepest questions of human existence is another question.
Incidentally …
DNA tends to be transcribed into RNAs which perform the main functions, or are further translated into protein. But it is by no means ‘inert’. It just tends to be, in modern organisms, a primary source of macromolecular sequence, rather than itself active. It makes sense to bury this vital ingredient in base-paired stability.
Also worth mentioning that there is no difference worth mentioning between DNA and RNA … well, a 2′ oxygen on the ribose and a missing methyl group on one of the four bases in RNA. That’s it.
That’s woo. Hand-waving. Even if we do not currently know the where and the how it certainly doesn’t follow that it’s in the DNA.
When the DNA sequences that contain the instructions are actually identified then I will believe the instructions are in the DNA.