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.
I understand PE would be saying its mutations friven in segregated parts of a population. Then they do well.
This slow sly change of small steps is what PE was against. further they said the fossil record rejected it.
In all this stuff its just guessing.
They presume things evolved and then, in these smarter days, there are problems with HOW ACTUALLY that could happen.
Ideas that are wrong eventually are found to not work however much its desired they work.
A paradigm change is acoming!
Or what regular folks call CORRECTING WRONG CONCLUSIONS.
I have no idea what it means to say that selection is shifting alleles to combine many small effects in one direction. Selection doesn’t do anything, it isn’t a process or a mechanism. Some reproduce, some don’t. That’s the entirety of what selection is. When we start to speak of it in terms of actually doing something, I think we are just substituting that term in there, for some force we don’t know.
Its the same way biologists talk in terms of teleology, when they claim they don’t mean teleology. If its not what they mean, then they should just stop saying it. But they have to, because they have to discuss something that they don’t what they mean.
Biologists complain about woo woo immaterialists talk. But I think the modern synthesis is about as woo woo as you can get. Its entirely mystical imaging.
Barely anyone here is qualified to discuss that paper.
Then don’t say anything in this thread.
Agree.
Then don’t say anything in this thread.
I won’t if you won’t.
Too late, you already did.
I won’t pretend that I’m qualified to discuss this article in any detail, but I was struck by the concluding paragraphs:
I found this quite interesting, as it led me to question my own enthusiasm for an extended evolutionary synthesis (EES). What exactly do we need a unifying conceptual framework for? Why would a unifying conceptual framework be epistemically preferable to a motley list of different causal factors (e.g. niche construction, phenotypic plasticity, drift, developmental bias, etc.)?
I like the implicit distinction drawn between universal factors and general factors, though I might want to worry a bit about this conceptual relation they are making between universality and a unifying conceptual framework.
As I understand it, their view is this: the original modern synthesis (OMS) was an overarching, unifying conceptual framework for biology because it made universal claims about life. The causal factors underpinning evolution, as conceptualized in terms of the OMS, were universal: there were no exceptions and they explained all biological phenomena.
In place of that unifying framework, they urge a pluralistic framework: there are many different causal processes in evolution which are sufficiently general (there are more than a few examples but rather these terms do pick out real patterns) but not universal (none of them apply everywhere and none of them are complete).
Just to focus on this bit about a plurality of causal factors with no overarching, unifying conceptual framework: the acceptability of the anti-synthesis depends on rejecting the principle of sufficient reason. Conversely, anyone who is in the grip of the PSR and thinks that an incomplete explanation is no real explanation at all will want to reject the anti-synthesis and hold out hopes for an extended evolutionary synthesis.
That sounds about right to me.
I’ve been disagreeing with Darwinism (particularly the emphasis on selection), as I’m sure you have noticed. However, when that conference was proposed to advance an EES, I found that I could not support it.
The problem for me was that much of what the EES people wanted to study, was already being studied in areas such as evo-devo — or at least it seemed that way to me.
The EES folk didn’t like that all of the eggs were in one basket (the selection basket). So they wanted to put them in a different basket.
Viva diversity.
I found the last comment in response to reviewer Eugene Koonin, to be the take-home message:
It seems to say something I’ve been thinking myself for some time. If we really want a theory of evolution that can encapsulate all it’s known and manifestations, and even worse, many of the consequences of cross-generational evolutionary change, it’s going to be extremely broad and general. And with such a general theory, you will lose predictive detail. Evolution can manifest itself in so many different systems, from narrow biochemical scope (the evolution of a single enzyme over time), to the evolution of entire biospheres or continent-level ecosystems.
We have good theories we “need” for each of the domains of investigation Arlin mentions, and I agree it would be a mistake to try to bring them all together into a single master-theory of evolution, as that very attempt can only degrade the detailed predictive and explanatory power a more narrow and focused theory of evolution designed to fit a specific domain.
What do we want the theory of evolution to explain?
Why?
Because some people hope to get beyond a “Well, it just happens…” view of the world, that’s why. I understand from your writings that seems to be a satisfying enough explanation for you (it goes along with your teleology without a goal stance, which I find completely irrational), but I think for most people it is wholly inadequate as a final truth.
I’ve not seen a well-articulated explanation for this notion that “selection doesn’t do anything.” And based on Phoodoo’s statement above, he doesn’t really understand what selection means. That some members of a group of organisms reproduce and some don’t isn’t selection; any notable and observable forces or conditions that create specific differentiations of reproduction is selection. This really shouldn’t be tough to understand as humans have been such a condition on domestic animals for eons.
Let’s take a simple example: the lop-eared rabbit. Humans bred rabbits with longer ears to rabbits with longer ears and kept selecting longer and longer eared offspring to breed until finally the rabbits’ ears became too long for the muscles to hold up. This is a well-documented example of a human selected characteristic.
The only difference in wild populations is that the environment places the constraints for selection on the organisms. There are many documented cases of conditions in a given environment changing and suddenly a sub-group of population of organisms with some variation in characteristics (say color) is preyed upon more than other members of the group. Low and behold, that end of the color variation of the group starts to decline as there are fewer and fewer offspring with that color born compared with the rest of the population.
Clearly selection is doing quite a lot. I don’t understand what is difficult to grasp in terms of selection’s impact in the above examples.
Which theory of evolution? 🙂
Interesting. But why restrict that to biology? Wouldn’t we need a theory of everything if we were to accept the PSR?
Yes. My point is that depending on what you answer, you will have to either settle for a single, broad but therefore not very detailed theory, or a host of more limited, but therefore also more detailed theories with greater explanatory power within their (more limited) area of remit.
I think that what Darwin and Wallace first alighted upon was in large part a version of the former. A very broad theory of evolution with a set of more general predictions and explanations. But exactly because of it’s broad potential explanatory scope a lot of subsequent authors have been able to “square” later findings with it.
Some biologists seem to want a theory of evolution that explains everything about biology. They want a grand synthesis of everything biology-related. The grand unified theory of biology. They want a theory of evolution that explains how a single cell (zygote) develops into fully grown, adult, multi-cellular organism, like a palm tree or a goat. They also want that same theory to explain how multicellularity evolved. I don’t believe it is possible to have a theory of evolution that can do all that and still be useful.
Either because, if you want it to have great explanatory power, it’s going to have so many factors built into it that it becomes impossible to comprehend for any human (and therefore practically infeasible to test or use), or conversely it will have to be so broad and vague it becomes hard to make rigorous, quantifiable or qualitative predictions.
We will have to settle for a set of smaller theories, compatible with each other, perhaps with some overlap around the edges, but with their own limited area of validity. To pick an example I think there will have to be a theory physiological and embryonic development, and that theory of development isn’t going to be able to explain how whole ecosystems evolve, or how the immune-system responds to certain pathogens, or even how multicellularity evolved. There’s going to be a theory of evolutionary change that explains how and why multicellularity evolved, but that theory isn’t going to explain everything there is to know about how physiological and embryonic development takes place. And so on and so forth for different domains. They’re going to be compatible, and have a significant area of overlap, but they’re going to be distinct theories.
Soon as I saw the reference to mutationism I thought ‘Arlin Stoltzfus’.
I don’t think I follow this. I understand that a theory of everything isn’t going to help explain anything in particular. Make that theory too broad, and it does become “it just happens” because it’s not explanatory in any useful way. If you are saying it’s better to say THIS happens because of this, while THAT happens because of that, I agree with you.
Kind of like the debate between the big G of “general intelligence”, and a constellation of little gs, when it comes to evolution maybe the search for an evolutionary BIG T truth is futile, while many little truths, each explanatory in its own domain, is more useful for our understanding.
I suppose some might consider me qualified to comment on all this. Things are crazily busy today, so I won’t comment in detail. I just want to raise one issue:
Is the debate on this subject just a matter of what name we call our views on evolutionary phenomena? Or is this arguing that we should change our views?
The former, I think.
No.
If only there were one single coherent theory that covers everything.
I suppose that accepting the PSR means that our desire for understanding wouldn’t be entirely satisfied until we have a comprehensive theory of everything.
I do think there’s something importantly right about how Sellars describes the intellectual vocation of philosophy:
“The aim of philosophy, abstractly formulated, is to understand how things in the broadest sense of the term hang together in the broadest sense of the term. Under ‘things in the broadest sense of the term’ I include such radically different items as not only ‘cabbages and kings’ but numbers and duties, possibilities and finger snaps, aesthetic experience and death. To achieve success in philosophy would be, to use a contemporary turn of phrase, to ‘know one’s way about’ with respect to all these things, not in that unreflective way in which the centipede of the story knew its way around before it faced the question, ‘how do I walk?’ but in that reflective way which means that no intellectual holds are barred”
That said, I also think that there’s something importantly right about Rumraket’s point — which I deeply appreciate — that when it comes to scientific theories, there’s a trade-off between explanatory scope and explanatory power. A theory of sufficiently broad scope to encompass radically diverse phenomena will be of comparatively little use in explaining any of them with precision. We might well be better off with a patchwork-quilt of many different theories than with a single big theory that has little explanatory power about any particulars just because it encompasses so much.
That seems right to me! And I like the parallel. We might conclude that we should not expect too much by way of a single comprehensive theory of everything precisely because the human mind is basically modular. I got a lot out of Cognitive Pluralism on this point myself, though in that book Horst does not consider in much detail the implications of his view for metaphysics.
Flint,
No, what I am saying is we need a theory that is bigger than just, “The change in organisms is due to shifting of allele frequencies due to the weeding out of some through death.”
There needs to be a theory that answers- Why do organisms exist? Why do novel, new, precise and successful features exist. This is at the heart of the human struggle to understand itself.
If someone is satisfied to have this answer be- Well, because allele frequencies can change, due to many factors including varying rates of reproduction, then I would call that person not very curious. I wouldn’t call that person a successful philosopher either.
Darwinism no longer answers the question about why we exist. For a long time people believed it did. They were duped. Now a new breed of biologists is trying to sell them Darwin-lite, and calling it an explanation for life-The Modern Synthesis.
That is selling snake oil in my opinion. If Rumraket and KN and the like are satisfied to have a theory for how cells divide, and another theory for embryo development, and then say, Well, that’s good enough for me, let’s call it a day, then that’s up to them. But I wouldn’t call that seeking truth in any meaningful way. That doesn’t get you to the “WHY”, which they seem to be claiming is not all that necessary or important.
I laugh at that notion.
In my opinion, a patchwork of many different theories is an incomplete job that has almost no usefulness, intellectually. It might be all we are capable of, but it certainly isn’t what we should aim for.
If that was all we were ever capable of, then for sure just sitting in contemplation about your breathing is more satisfying.
“No” is wrong. I say “Yes”. Nyaa nyaa nyaa so there.
phoodoo,
As I see it, this line of objection underscores the difference between science and philosophy. There’s no reason to think that scientific theories will be answers to philosophical questions. A good scientific theory will give us an empirically confirmed model of the causal processes that underpin some observable regularities. Philosophical responses to deep perplexities about the meaning of human existence are a different thing altogether!
Here’s another important difference: I’m pretty sure that science is progressive, in the following sense: a successor scientific theory relative to a domain of phenomena will be a better theory than its predecessor. I don’t think that philosophy makes progress. I think that Plato, Confucius, Epicurus, and the Buddha should be taught and read as if they are our contemporaries. It’s hard (if not impossible) to read Ptolemy, Galileo, or Darwin the same way.
I do think that science and philosophy are complementary (as are art and philosophy, in a different way). But they are nevertheless distinct. One of the biggest things we can learn from the 19th and 20th attempts to turn philosophy into a science or replace it with science is that such attempts are doomed to failure.
Darn. I was hoping you were too busy to notice. 🙂
We already have a patchwork-quilt of many different theories.
I’ve been preaching that for months on end.
The advantage of the OMS was that it was empirical. Testable. Falsifiable. Scientific. Coherent.
Sadly, it turned out to be a failure. So now we have no master theory, no unity, and no coherence. These are the facts.
I guess I’m not sure what you’re after here. Imagine, as an analogy, a Martian trying to understand a “theory of transportation”. Yeah, moving from point A to point B describes the process, just like “the details of life change over time” describes evolution.
But taking a closer look, the Martian finds that no particular detail is universally true of transportation. Drifting down a river on a raft has little in common with driving a car around a racetrack, which has little in common with riding in an airliner. Every distinct form of transportation can be explained, in great detail, but where is the theory of transportation in all this? Is there one? Is transportation impossible to understand in the absence of such a theory?
I think the set of mechanisms by which novel features come to exist (and are always in a state of flux, slightly new and novel in each generation) is pretty well understood. Certainly understood well enough so that computer models incorporating them produce sequences matching real-world observation in stunning detail. Why you find these understandings inadequate for your purposes, requires that I understand your purposes. And I admit I don’t.
Mung,
But do we need a single comprehensive theory of all biological phenomena, when we do have a patchwork quilt of various explanations of different causal processes?
I harbor the deep suspicion that the need for a single comprehensive theory in science is basically a hangover from the good old days when it seemed like Newtonian physics was the single comprehensive theory of fundamental physics. The idea that there could be a single set of unifying laws for all (empirical) reality was terribly seductive.
Alas, it turned out not to be. Even today we have at least two (if not three) theories of fundamental physics: general relativity, quantum mechanics, and possibly thermodynamics (there’s a question as to whether thermodynamics is reducible to quantum mechanics, I gather). And we know that GR and QM are not mathematically compatible.
When we don’t even have a single comprehensive theory of fundamental physics, why should we expect to have unifying comprehensive theories in any other branch of empirical science?
But we still have many different theories, each of which has its own internal consistency and its own explanatory scope, and each of which is empirical, testable, and falsifiable.
It may be laudable to yearn for something more than that in philosophical speculation about ultimate reality, but we shouldn’t look to the sciences for the satisfaction of our philosophical aspirations.
I wonder. I had thought that the dream of grand unifying theories was an outgrowth of the (rather a priori) conviction that the universe is consistent, and permits no true paradoxes. And if everything MUST be consistent with everything else, surely there can be unifying explanations of great hunks of kinda related stuff, tying them together in understandable ways.
I’m inclined toward the view that it comes from design thinking.
People start with “How does X work?” And then they tend to think along the lines of “How could we design X?” And that leads to the (probably false) idea that we are trying to discover a design that exists in nature.
KN.
Those are separate issues. In principle, you could have a unified theory of evolution even if the lower-level phenomena (such as mutation) rested on non-unified theories of physics.
Neil,
That doesn’t explain people who don’t think the universe is designed but nevertheless expect there to be a TOE.
No they are not facts.
The absense of a master theory does not imply there is no “unity” or a lack of coherence between some set of smaller sub-theories that survive.
Take what is essentially two sub-branches of physics: Chemistry and geology. There are theories of chemistry and theories of geology, they each have their domains of validity and areas of remit. But there is also some overlap between them (in a sub-branch of both called geochemistry). They are entirely consistent, both internally and with each, and so coherent. It isn’t necessary to have a super-theory of it all in order for it to be coherent and intercompatible.
For the same reasons, it turns out the subject of biology encompasses such an incredible diversity of phenomena it is a pipe dream to hope for a single unifying theory of it all. It is better to hope for a smaller set of more precise theories, compatible with each other and with a bit of overlap, that can explain things in more detail and therefore be more useful.
Mung wrote
Kantian Naturalist replied (snipped)
and Rumraket replied (snipped)
Or maybe a more holistic approach is in order. Here is the conclusion of an essay by Stephen L. Talbott:
Genes and the Central Fallacy of Evolutionary Theory: Is DNA the Decisive Heritable Material?
The more we are informed by the sophisticated advances in the techniques of biological research the greater is our need to abandon the narrow view that genes and DNA are some sort of master controllers of living systems. We should be listening to what the science is telling us.
Darwin was antesynthesis. Mung is antescience.
CharlieM,
Which is that genes/DNA are some sort of ‘master controllers’ of living systems.
Here’s my Grand Unified Theory – organic change results from variation and constrained sampling of that variation. Thangyouverrymuch. I’m off to prepare my Nobel acceptance speech.
Allan Miller,
Concerning regulation Talbott links from the essay I quoted to further writings of his on this subject. In a section, Who Regulates the Regulators, he has this to say about the p53 protein:
Maybe you could give us an example of what you consider to be a gene/DNA master controller.
CharlieM,
All control molecules root in DNA as far as I am aware. I’d be interested in an exception. I am not aware of any RNA that is not produced by DNA transcription. I am not aware of any protein that is not produced by mRNA translation – even if subject to RNA editing/posttranslational modification: those actions are themselves performed by molecules that ultimately root in DNA.
It is kind of vital that a function be inherited, and that happens through DNA (despite ingenious attempts to use a more colloquial understanding of ‘inheritance’ to include short-residence molecular chattels).
Allan Miller,
Shakespeare’ play’s are rooted in the English language but it is not the words that determine how he used and arranged them. I am not interested in the fact that proteins are rooted in DNA, I am interested in the controlling process.
Here is a recent paper:
Meditation and yoga can ‘reverse’ DNA reactions which cause stress, new study suggests from Coventry University.
Where is the DNA master controller here?
CharlieM,
Bad analogy, which I’m going to waste no further time on.
No that interested, then. Why ignore the basic facts? Understanding the role of DNA does not impede understanding of the overall process. You’re sure there’s a ‘master controller’, and you’re sure it’s not in DNA, it’s in some mystical Elsewhere. Nonetheless, it all starts with DNA.
But we don’t just inherit DNA, we begin as an egg cell with its cytoplasm and associated organelles. It is a functioning complete organism from the very beginning.
CharlieM,
So you’re going with the ‘molecular chattels’ view of inheritance. Well, doesn’t work. They are produced from DNA.
Yes, I KNOW that DNA is never presented naked. That in no way changes my point.
No. The master controller is the organism.
CharlieM,
Isn’t.
And it is obvious from your point that you can’t see past your reductionist mindset.
CharlieM,
Yeah, yah boo sucks to you too. It remains a fact – elucidated by a whole bunch of ‘reductionists’ – that all biological molecules trace back to DNA.
This ‘control by the organism’ doesn’t even have a mechanism – there is no route from ‘me-as-an-organism’ into my sperm and from there to the zygote of my next child (where I compete for the steering wheel with half of my wife, or a quarter each of her parents).
One can pat oneself on the back for being ‘holisticer-than-thou’, but there’s no point denying facts to suit.