Here we go again: someone arguing that DARWIN WAS RONG (well, he was, on several issues) and also that DARWIN’S INTELLECTUAL DESCENDANTS ARE RONG TOO. But this time it’s not a creationist but a card-carrying biologist, and a famous one, too.
Matthew Cobb ruined my morning by sending me a video of the renowned physiologist Denis Noble (born 1936 and a professor at Oxford until 2004), whose name is followed by a veritable alphabet soup of honors (CBE, FRS, FRCP). His contributions to physiology are apparently multifarious, though I confess I don’t know much about Noble or what he did. Nevertheless, in his dotage he’s taken to writing and talking about how modern evolutionary biology (“neo-Darwinism” or “the Modern Synthesis”) is wrong, and that I know something about. And Noble, as you’ll see in the video, is wrong; in fact, I’d use the physics adage and say “he’s not even wrong.”
Noble’s motivation, apparently, is to put physiology back at the High Table of Evolution, as Steve Gould wanted to do with paleontology. That is, Noble argues that the current paradigm of evolutionary biology doesn’t leave much of a niche for physiology. He’s butthurt about that! And so he constructs a case that not only is the Modern Synthesis wrong, because all its tenets have been disproven, but that his own “Nobleian Synthesis” leaves a central place for physiology. What a mitzvah!
The views in the video below were also given Noble’s paper published in Experimental Physiology this year (reference at bottom, free download). I read that paper and intended to write about it, but its misguided arguments and willful ignorance angered me so much that I moved on to other things. Now, with Noble’s video staring me in the face, repeating his stupid arguments against neo-Darwinism, I must respond. I can do no other.
If you’d rather read his views instead of spending 38 minutes watching this video, read his paper. If you’re an audiovisual type of person, watch this video, described on YouTube this way:
A major revolution is occurring in evolutionary biology. In this video the President of the International Union of Physiological Sciences, Professor Denis Noble, explains what is happening and why it is set to change the nature of biology and of the importance of physiology to that change. The lecture was given to a general audience at a major international Congress held in Suzhou China.
Here are Noble’s contentions and why they’re wrong:
1. Mutations are not random. This is a central tenet of evolutionary biology, which Noble says has now been disproven. It hasn’t. He argues that there are mutational hotspots in the genome, and that mutation rates can change in response to the condition of the organism or its environment.
That is true, but says nothing about the randomness of mutations. What we mean by “random” is that mutations occur regardless of whether they would be good for the organism. That is, the chances of an adaptive mutation occurring is not increased if the environment changes in a way that would favor that mutation. The word “random” does not, to evolutionists, mean that every gene has the same chance of mutating, nor that mutation rates can’t be affected by other things. What it means is that mutation is not somehow adjusted so that good mutations crop up just when they would be advantageous. My friend Paul Sniegowski, a professor at Penn, uses the term “indifferent” instead of “random,” and I think that’s a better way to describe the neo-Darwinian view of mutations.
And there are no experiments—none—showing that mutations are not indifferent, and plenty showing they are. In other words, Noble’s characterization of neo-Darwinism’s error is simply misguided.
2. Acquired characteristics can be inherited. In support of this neo-Lamarckian view, Noble trots out the tired old horse of epigenetics, arguing that environmentally-induced changes in DNA can be transmitted for several generations, presumably by differential methylation of the DNA. And that is also true.
But what is not true is that a. these changes are frequent, b. epigenetic changes, when they occur, are always induced by the environment, and c. epigenetic changes produced solely by the environment are the basis of adaptive evolution. There are four types of evidence for these contentions.
First, when we map adaptations in organisms, they invariably turn out to be changes in the DNA (either the structural or regulatory bits) and are not purely epigenetic, that is, are not based on methylation of DNA that is itself not coded in the genome.
Second, as I just noted, adaptive methylation, such as “parental imprinting”, in which the father or mother contributes differently methylated DNAs that do different things in the zygotes and offspring, is based on instructions in the DNA itself. That is, the DNA carries instructions that say something like, “If you’re a male, methylate this bit of DNA in your sperm.” That is not environmentally-induced or Lamarckian change of the DNA. It’s based on simple, garden-variety evolution of genes themselves.
Third, I know of not a single adaptation in organisms that is based on such environmentally-induced and non-genetic change. Geneticists now know the genetic basis of dozens of adaptive traits that differ between populations and species. All of them reside in the DNA. If non-genetic adaptive change was common, we would have found it.
Finally, it would be odd if pure epigenetic changes were the basis of adaptations, because such changes are not inherited stably. For an adaptation to become fixed in a population or species, it must be inherited with near-perfect fidelity. And that is not the case for all environmentally-induced modificatons of DNA. They eventually go away.
Because of the supposed environmental acquisition of inherited traits, Noble claims in his talk that the Central Dogma of genetics (genes produce DNA produce organisms) is flat wrong. But he fails to show a convincing case of long-term evolution induced by an environmental modification of the genetic material. I’ve written extensively on the problems with the “epigenetically-driven” paradigm of evolution, and you can find posts on this site simply by searching for “epigenetic.”
3. The gene-centered view of evolution is wrong. Noble clearly has a beef about his colleague Richard Dawkins, and spends a lot of time in his talk arguing against both the notion of “selfish genes” and the idea that the gene is the true unit of selection rather than, say, the cell.
Here Noble is deeply confused. He decries the gene-centered view of evolution because, he says, “well, cells replicate too, and the cell carries the DNA, so the DNA can’t itself be the unit of reproduction.” That’s just dumb. Cells are transitory, and DNA is not. A cell is not passed on from one generation of individuals to the next, but the DNA molecule, which is in some sense immortal, is. This point is made clearly in Dawkins’s The Selfish Gene.
Noble also claims that all biologists now recognize that selection is “multilevel” rather than just at the level of the gene. But he doesn’t explain what he’s talking about. Clearly, multilevel selection is logically possible, but we don’t know of many cases. In the case of the most famous form of “higher level” selection—group selection—I can’t think of a single convincing case in nature where a trait has plausibly evolved through that process.
What bothers me is that this kind of palaver sounds superficially convincing to those who don’t know a lot about evolution, and that may include the biologists in Noble’s audience.
4. Evolution is not a gradual gene-by-gene process but is macromutational. Here Noble cites examples of entire blocks of genes being moved around, or acquired from other species, in a leap. This, he says, invalidates the neo-Darwinian view of gradual evolutionary changes in genes.
And he’s right that those kinds of large changes sometimes happen. We now know, for example, that adaptations can originate with a big part of a gene “jumping” in an organisms to fuse with another gene, producing a hybrid gene that has beneficial consequences to the individual. Something similar occurs when organisms absorb genes from different species, as bacteria often do. Those changes can also occur in eukaryotes, like rotifers, that can take up DNA from, say, fungi, and the absorbed genes can be beneficial.
But that doesn’t show that the modern synthesis is wrong, for those big jumps or horizontally-transmitted changes in DNA must still obey the rules of population genetics. They are equivalent to mutations, but they’re just BIG mutations. The Modern Synthesis has expanded a bit to take account of these new genetic findings, which only recently became possible. But their discovery hardly invalidates the Synthesis.
Noble claims in this lecture that these kinds of changes overturn the view of evolution as a “branching bush” because genes can leap between distant twigs. He’s wrong. These kinds of changes are rare except in bacteria. If they were common, the reconstruction of evolutionary trees through systematics would be impossible. Different genes would show different patterns, and we’d never be able to use multiple-gene analysis to reconstruct the ancestry of a group of organisms. We wouldn’t be able to find out, for example, that our closest living relative is the chimpanzee. But the fact that multiple genes do show similar phylogenies, especially between species that are not extremely close relatives, is proof that Noble is wrong.
5. Scientists have not been able to create new species in the lab or greenhouse, and we haven’t seen speciation occurring in nature. This is what really burns my onions, because Noble is flat wrong here, and the study of speciation is my specialty. I’m not even sure why Noble makes this argument, which resembles a creationist argument. We haven’t seen new species arise before our eyes, ergo Jesus!
If species arise through evolution, as they must—and surely Noble admits this—then we should be able to see them forming in nature, even though their formation usually takes a long time: thousands or millions of years. That is, we should be able to see incipient cases of speciation: populations that are in all stages of evolving reproductive barriers against other populations. And indeed we do: this has been documented since the time of Ernst Mayr and Theodosius Dobzhansky in the 1930s and 1940s. Further, we have been able to produce new species in the laboratory through a mechanism of speciation important in plants: polyploidy (the appearance of a new species when either a pure species doubles its genome on its own or does so after hybridizing with a different species). Polyploidy is responsible for about 5-10% of new plant species, and we can make new polyploid species in the laboratory. We’ve known this for over a half century, and Noble should know that, too. It’s garden-variety evolutionary knowledge. But Noble doesn’t seem to have learned it.
Further, we can make “diploid hybrid species” in the lab by hybridizing two species and letting their mixed and somewhat incompatible DNA sort itself out over several generations. What you can get is a non-polyploid hybrid species that is reproductively isolated from both parental species—that is, a new lab-produced species. Loren Rieseberg has done this in sunflowers, and we’re beginning to find such cases occurring in nature.
Noble, then, is talking out of his hat when he argues that we haven’t been able to produce new species. But even if we hadn’t, that doesn’t mean that we can’t see speciation occurring in nature. As I said, it’s usually a gradual process, and if we can see all possible steps in nature, and show that the more distantly related populations show more reproductive isolation (as I did in a pair of papers with Allen Orr), then one has strong evidence that reproductive isolation increases gradually in nature as populations become geographically isolated for longer and longer periods. This is the same way we have figured out how stars evolve. We rarely see a single star changing, but we can trace the process of stellar evolution by seeing all stages occurring in different stars in our galaxy.
I’m writing this post in a bit of anger, as Noble’s attacks on the modern synthesis are both poorly informed and clearly motivated by his ambition to make physiology a central part of evolutionary biology. Although he’s an FRS and famous, he wants more: he wants his field to be central to evolution. But such misguided hubris is not the way science is supposed to be done. And physiology is already important in evolutionary biology. It’s the reason why we look at the effects of a gene substitution, for example, not as a simple one-gene-produces-one-trait issue, but as a the gene’s overall effect on reproductive output through its effects ramifying through the complexities of development. Noble says that evolutionists are guilty of this “one-gene-one-trait” error, but he’s just wrong: I don’t know a single person in my field who holds this simplistic view.
None of the arguments that Noble makes are new: they’re virtual tropes among those people, like James Shapiro and Lynn Margulis, who embarked, at the end of their careers, on a misguided crusade to topple the modern theory of evolution.
However famous Noble may be in physiology, he’s a blundering tyro when it comes to evolutionary biology. He might try discussing his ideas with other evolutionists and listening to their responses. He obviously hasn’t done that, and yet travels the world trading on his expertise in physiology to show that the edifice of modern evolutionary biology is rotten. And he writes papers to that effect, including the dreadful piece referenced below.
But what’s really rotten is Noble’s knowledge of the field and his claim that virtually every assumption of neo-Darwinian evolution is wrong. In fact, his arguments are so rotten that they stink like old herring.
They’re not even wrong.
Noble, D. 2013. Physiology is rocking the foundations of evolutionary biology. Exper. Physiol. 98:1235-1243.