Evolution is true, but are mutations really random?

Source: Wikimedia Commons.
The evidence is overwhelming that evolution by natural selection is true: organisms change from generation to generation by the accrual of genetic mutations. These mutations are selected for, or against, according to the ability of the resulting organisms to survive and reproduce in their respective ecosystems. A video released by Harvard Medical School a few years ago vividly—if didactically—illustrates the process:

However, an extra idea is often conflated with the foregoing: whereas natural selection is demonstrably not a random process, the mutations underlying the process are consistently assumed to be. The problem is that evidence for natural selection is not evidence for random mutations: nature will select for survival fitness whether the mutations themselves follow a trend or not.

To demonstrate that the genetic mutations underlying evolution are random, one would need a fairly complete record of (a) the mutations themselves, as they occurred throughout the history of life on Earth, including those discarded by natural selection; and (b) the corresponding phenotypic characteristics. Only then could one run a randomness test to verify that no phenotypic trends are present before natural selection plays its role. Of course, the fossil record is far too sparse to allow for such a test.

So the assumption that genetic mutations are random has, strictly speaking, no empirical basis. Its motivation is merely subjective: many cannot fathom any plausible mechanism that could impart a pattern on the mutations themselves. Compelling as this may sound, lack of imagination and a subjective sense of plausibility aren’t valid reasons to pronounce scientific facts.

The spirit of scientific investigation is precisely to look for yet-undiscovered natural patterns, thereby implicitly assuming—if anything—that they, in fact, exist. To affirm, on account of subjective dispositions, that genetic mutations are pattern-less is arguably antithetical to the very spirit of science.

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Moreover, scientific results and speculations have violated our sense of plausibility so often that, by now, we should have learned to be cautious about it. For instance, when compared to the hypothesis—seriously pushed by many physicists to explain the bizarre fine-tuning of universal constants—of countless parallel universes, for which there is no shred of empirical evidence, the possibility of an inherent natural bias underlying genetic mutations doesn’t seem so absurd to this commentator.

In an attempt to be more objective, one could argue that genetic mutations are quantum-level events, which have been demonstrated to be inherently random. But since the hypothetical trends in question are phenotypic—that is, biases towards certain body structures, functions or capabilities—they necessarily entail many quantum events. At such a compound level, global patterns across events can be consistent with individual events meeting randomness criteria. Let me illustrate this with a simple analogy.

Imagine that you toss three dice on a table, multiple times. After each toss, you inspect each die separately and verify that they randomly display a number from one to six. But when you look at all three dice together, you realize that either they all display an even number or they all display an odd number. The resulting global pattern not only clearly violates randomness, but is also constituted by individual events that, when inspected in isolation, meet randomness criteria. Therefore, that individual quantum events are random doesn’t preclude the possibility of non-random global mutation patterns.

Indeed, the possibility of there being global patterns of behavior in nature that transcend locality restrictions is opened up by quantum mechanics itself. In the words of physicist Erich Joos, “Because of the non-local properties of quantum states, a consistent description of some phenomenon in quantum terms must finally include the entire universe.

Moreover, although physicists can test individual quantum events in the laboratory and verify that they are random, it is impossible to discern a global pattern within the complexity of the physical world at large; there are just too many ‘dice’ to keep track of under controlled conditions. So for all we know and even can know, genetic mutations may follow yet-unrecognized phenotypic trends operating non-locally across mutation events.

As a matter of fact, there are empirical suggestions of fundamental natural regularities—‘laws of nature’—irreducible to microscopic events. If so, such a precedent should compel one to avoid outright discarding, on the basis of mere intuition, the possibility of unknown macroscopic laws biasing the genetic mutations that drive evolution.

Finally, one could argue that we don’t need anything other than random mutations to explain the variety of life, so that postulating a pattern prior to natural selection would violate Occam’s proverbial razor. But we don’t really know that randomness is enough, do we? The only way to verify it would be to run a quantum-level simulation of the evolution of life to see if, with trendless genetic mutations as input, we could reproduce the biological variety empirically observed. Such simulation is, of course, impossible. Only toy models are feasible, but these aren’t representative of the complex reality we are trying to understand. If anything, the amazing richness of life seems to suggest precisely a natural bias in that direction.

Notice that I am not claiming that such bias exists; I don’t know it either way, this being precisely my point. I am simply pointing out that the hypothesis cannot be discarded. Moreover, I am not hypothesizing any deliberate intervention in natural affairs by some supernatural agency. I am simply raising the possibility of yet-unrecognized but natural regularities, which impart trends on genetic mutations. Nothing we know today precludes this possibility.

I also acknowledge that, to many, the hypothesis of an irreducible phenotypic bias feels so implausible as to be ignorable. There is nothing wrong with holding such an opinion. But passing opinion for established truth is a problem, for if we make an exception to the scientific practice of separating subjective views from objective facts, we open Pandora’s proverbial box.

The very notion of ‘randomness’ is already loaded and ambiguous to begin with: although it is defined as the absence of discernible patterns, theoretically any pattern can be produced by a truly random process; the associated probability may be vanishingly small, but it isn’t zero. So the claim that a natural process is random not only amounts to little more than an acknowledgement of causal ignorance, it can also be construed so as to be unfalsifiable.

On top of such inherent problems, today the idea of random mutations has become so intertwined with that of evolution by natural selection that, remarkably, the overwhelming empirical evidence for the latter is implicitly misconstrued to be evidence for the former. This is a serious inaccuracy, for there is arguably no other natural process as relevant to us as the nature of life.

If anything deserves the full rigor of interpretation required by the scientific method, it is the evolutionary mechanisms that produced us humans. Humbly acknowledging what we do not know about them is imperative, lest we arbitrarily eliminate interesting avenues of investigation.


  1. Bernardo,

    I have only very recently been acquainted with your work. You have undoubtedly blown me away with your vast knowledge and well thought out arguments in your books and blog posts. My perspective on life has completely changed. Thanks for all the work you do!


  2. This is great, the parabola with the dices can explain a lot of things to me; like the transition from indeterminate to determinate reality. People use to see it like two different states of reality but this shows it just relate to simultaneously.

  3. "As a matter of fact, there are empirical suggestions of fundamental natural regularities—‘laws of nature’—irreducible to microscopic events. If so, such a precedent should compel one to avoid outright discarding, on the basis of mere intuition, the possibility of unknown macroscopic laws biasing the genetic mutations that drive evolution." The controversial British biologist, Rupert Sheldrake, has devoted his career to providing such "empirical suggestions" to support (or refute) his theories of "morphic fields" (which help shape the evolution of individual organisms) and "morphic resonance," (which help connect the individuals of a species). His website explains both the methods and results of his scientific research, allows visitors to participate in his ongoing experiments, and offers a plethora of written, oral, and video presentations of his provocative theories, which include the suggestion that nature should be understood as acquiring habits instead of obeying laws. If you like Bernardo's observations in this post--especially the questions he raises--you would probably enjoy spending some time on sheldrake.org.

  4. Dear Dr. Bernardo,
    I would like to express my heartfelt gratitude for your creative work.

    Please have a look:
    Swenson, R. (1997). Evolutionary theory developing: The problem (s) with Darwin's dangerous idea. Ecological Psychology, 9(1), 47-96.

  5. Mutation and nautral selection merely remove information and not add information which is the basic ingredient of the evolution process to produce new species . ( even Dawkins does not have any answer for this )


    The very notion of ‘randomness’ is already loaded and ambiguous to begin with: although it is defined as the absence of discernible patterns, theoretically any pattern can be produced by a truly random process; the associated probability may be vanishingly small, but it isn’t zero....

    Any pattern is a pattern in one way or another and threre is always a none zero chance of an improbable pattern to happen . How ever having a mathematical pattern does not mean any bilogical pattern can survive the nature simply because it has a none zero chance of occurance.


    I donot think involving quatum randomness is much relavant to evoloution .

  6. The more we learn of epigenetics, the more it may turn out that externally driven mutations may become more plausible in some cases.

  7. All good sense as usual. You seem to be exactly right about the confusion between selection and mutation.

  8. As far as I know, what I experience as "being" is as a complex adaptive system oriented toward the goal of participating in nourishing and defending the coherency of this existing system; meaning I am able to use novel behaviors (if necessary) to navigate various environmental obstacles toward specific ends and I have built in drives to protect the coherency of the adaptive system that I am an expression of. As a product of the greater whole of nature of which I am inseparably part, I see no reason this “nourish and defend in the context of the environment” trait from which I am composed would be unique to the membrane of relationships that I experience locally as "me". It must be within the realm of possibilities, if not fact, that the same way our cells and organs are isomorphically self similar and differentiated, yet simultaneously aligned around the same nourish and protect axiom, that this may be an isomorph that is already present in the whole of nature - that we (nature) are finding our self – we are re-membering - and we are but one form of this repetitious expression of events that conspire toward this end of finding a homeostatic equilibrium in the context of the greater whole, until we together become one and the same with that whole.
    I could be missing something(s)

  9. Evidences of animal-homosexuality among animals had been denied not only by proponents of Intelligent Design (for the political reasoning that their deity hates human homosexuality) but also Darwinists, for violating the supposedly-fundamental principle “sexual organs function only for repro”.

    Might also be noteworthy that some Creationists like (the Islamic) Harun Yahya (alleged to be recycling arguments of Behe and Dembski; most notably Irreducible Complexity) theorizes “instinct” is instead “divine guidance”, which means that homosexual, bisexual, trans-sexual and trans-gender animals are indeed “created that way” by his deity.

    We shall see where these “interesting avenues of investigation” lead. But ONLY for the avenue of God, I would humbly like to bring your attention to the following:

    1. The Story of Creation as claimed by the deity of Judeo-Islamo-Christianism was plagiarized from an ancient-Sumerian myth. An instantly-searchable evidence is photograph of Sumerian Temptation Tablet, while a detailed presentation on how European churches had systematically attempted to confiscate and conceal “inconvenient” archaeo-findings (which religio-politically also benefits Islam), is in the book Genes, Giants, Monsters and Men (Joseph P. Farrell).

    2. The Story of Noah’s Ark is a recycled version from Epic of Gilgamesh (also Sumerian). The following shows how evolution-debunking ^arguments^ by Creationists, when applied in equal degrees of logical honesty and consistency towards the scriptures of Abrahamic Religions, will make the Torah, Bible and Quran to be insulting the deity they portray as an ^all-knowing^ creator of all:

    3. Also equally insulting to an all knowing creator of all, is the deity’s supposed-claims that the earth is having the moon and stars orbiting it (Galilei and Darwin were more fortunate to be born in Europe instead of Middle East:-).

    4. Additionally, the deity of Judeo-Islamo-Christianism makes one particular claim that everything exists ONLY in (opposite yet completing) pairs, especially animals (Genesis 7:2-3 and Quran Suras 36:36 & 49:51). But in addition to the obvious existence of homosexual, bisexual, trans-sexual (clownfis), trans-gender (cuttlefish) and intersexual (fruit flies) animals, there are also asexuals and even parthenogens within a species which clearly has males (komodo). An ultimate proof that this deity knows not very much about the biological universe It supposedly created, is the species Aspidoscelis uniparens.

    5. Thus, which “Intelligent Designer” whom will be talked about? Behe and Dembski, in their evolution-debunking ^arguments^, repeatedly attempted veiling the ultimately-inevitable conclusion that they were indeed propagating Christianism’s Jehovah. Presently we have Harun Yahya and Zakir Naik as champions for Islamism’s Allah. But we still have Ahura Mazda and Amaterasu among dozens of (monotheistically-personified) deities. So again, which Intelligent Designer --and why not the other?

    6. When the Torah, Bible and Quran (among others claiming what God is --and what It dislikes) failed proving themselves to be coming from an ^all-knowing^ creator of all, then must this “intelligent designer” still exist as a reality-observing personality? Why can’t It be the reality itself (noting that Socrates, Spinoza, Einstein and Buddha were notable for rejecting the personal God)? Now if God is reality itself, then what has been defined as “randomness” might just need re-consideration, despite still NOT in any way proving the existence of God’s Judeo-Islamo-Christianism ^personality^.

    “If logic is a test of faith, is religion a test of logic?” --Philosoraptor.

    1. All very valid points. I'm no fan of Dembski, Behe, or Intelligent Design "Theory", but I'm not sure how relevant they are to Bernardo's argument.

      Maybe this is a fallacious "argument from incredulity", but my conscious experience is of a nature that I find extremely unlikely (impossible,actually) to have come about via the forces of natural selection acting on non-conscious matter. My body? Sure. My behavior as it appears from an outside, third-person perspective? Sure.

      But my subjective, first-person experience? Seems about as likely to have come about BY ANY MEANS from within a physicalist perspective as me discovering a perfectly square perfect circle in my back yard tomorrow.

      Trying to explain the existence of subjectivity/consciousness by reference to ANY arrangement of non-conscious matter is like trying to explain nuclear fusion via bird migration patterns. It's simply a category error.

  10. The Materialist Darwinian Evolutionary paradigm is clearly false. Both quantum theory and the Evolutionary-Developmental discoveries refute it. Careful research shows that a quantum mind-only intelligent design (i.e. the design resides in quantum potentiality, the design is manifested by primordial consciousness) is correct - https://www.amazon.co.uk/Self-Perceiving-Universe-Graham-Smetham/dp/1326907638

  11. I believe professor James Shapiro of University of Chicago says there is evidence that mutations are non-random