This is the second of four installments in a blog series by Russell A. Barkley, Ph.D. The full series is titled “Reason is a Type of Evolution (Universal Darwinism).” Dr. Barkley will speak and lead a discussion for RRNA on January 30th, 6:30 p.m., at the Libbie Mill Library. This series is not obligatory reading in order to attend, but it frames and supplements Dr. Barkley’s appearance. The next two installments will be posted over the remaining days before the 30th.

Reason is a Type of Evolution (Universal Darwinism)

Part II: What is Evolution?

Russell A. Barkley, Ph.D.

As I explained in Part I of this serial blog, Reason (and the Science based on it) share many similarities with biological (genetic) evolution by natural selection. Both involve the proposal and testing of information against the natural world for its agreement or disagreement with (conformance to) that world. The information so tested may be successful enough at agreeing with the natural world that it may be retained (survive) and replicated or reproduced again. Or it may so disagree with the natural world that it is eliminated from further survival and reproduction. In this way, the information or knowledge about the environment becomes increasingly more accurate (better adapted) to the natural world. Thus, Reason and biological evolution can both be viewed as specific instances of a general process by which information (no matter how coded and reproduced) is tested against and naturally selected by feedback from the natural world or environment.

This more general process of evolution is known as Universal Darwinism. It argues that the algorithm or set of steps involved in evolution is not limited to the genetic level of information but operates at every level at which knowledge about the environment is being accumulated. I am not the first to make this argument. More than 50 years ago, the renowned psychologist, Donald Campbell, argued that evolution is a general explanation for how information about the environment can accumulate over time and undergo continuous refinement (Campbell, 1960). As he claimed, anywhere in the universe that information about the environment (knowledge) can be found to have accumulated it will have done so by a Darwinian process of evolution (replication with retention and environmental selection).

The general algorithm or set of steps involved in evolution by natural selection has been the most well-studied at the biological or genetic level of information. One can take the 9 steps that characterize biological evolution and just rephrase them in a more general way that they might apply to any means by which information about the environment is being encoded, reproduced, tested, selected, and retained to be reproduced or used again. Those 9 steps are described below. From such a simple, stupid, and blind (unguided or un-designed) algorithm, complex forms of knowledge about the natural world can emerge.

The Steps Involved in the Evolution Algorithm

For any system of information to evolve, as in genetic evolution, it must involve at least these procedures or steps. While I separate them into 9, other writers on this subject may collapse some of the steps together. The number does not matter but the procedures do.

(1) There Needs to be a Storage Device: There must be a reliable storage device or memory base – some means by which information can be reliably stored and accessed. At the genetic level, we know this is DNA, although in the very early stages of the evolution of life it might have been RNA.

(2) Information Needs to Get Encoded: There must be a simple and reliable means by which information can be coded into the storage device. In the case of genetic evolution, this is just four little bits of information called nucleic acids that here we can simply call A, G, C, T.

(3) There Needs to be Some Means of Replication (copying, trials): At its core, the very essence or even definition of life is self-replication – a piece of genetic information is making a copy of itself. For evolution to occur there must be some means by which the information is copied (replicated or reproduced). In the case of genetic evolution, the very first living molecule was the first one to copy itself. That information functioned to create an organism. The organism was then tested in an environment to see how well it could survive and reproduce. Each replication or act of reproduction can be considered a trial. The copies being reproduced will be judged by the environment (see below) for their fitness or conformity to that environment – their relative capacity to survive to replicate again.

(4) There Needs to be Good But Imperfect Fidelity of Copying: Replication must create a highly similar copy to its original version. DNA serves to do this very well at the genetic level of evolution. However, no copy will be perfectly identical to its original or template. Errors always creep into the copying process because the world changes from one moment to the next. Those changes alone can affect the copying. Also, storage devices, like DNA, will show entropy or decay just as do all physical entities. This decay can cause errors in the knowledge encoding mechanism. But all that is needed for the process to continue is that the copy be good enough to work to serve its purpose – to replicate the information again.

(5) Mistakes (Mutations) Must Be Made: While this restates the above point that mistakes occur in the copying process, the emphasis here is on the mistakes themselves – they are a critical part of evolution. Fallibility (errors) is an essential ingredient in evolution because it creates variation in the information across the replications — a new piece or arrangement of information that did not previously exist. This leads to a variety of versions of the information being tested against the environment. The mistakes happen by accident and not by design, but they happen. Errors are ubiquitous in all of life. It is this blind, stupid, unconscious mistake-making that is the source of all new variations in information at the genetic level of evolution. The variation in information (genes) creates variations in the individual organisms built by and carrying that information. And that variation across individuals is then offered up to the environment to be judged for its survival value and a chance to reproduce again. This point cannot be over-emphasized – making mistakes is therefore absolutely crucial in the process of how evolution achieves new, more complex and better-adapted (efficient and functional) life forms (the manifestations of the accumulated knowledge). Most copying mistakes have no significant functional effect on the copy and many mistakes may actually be detrimental to its getting replicated again. Indeed some of the errors are absolutely destructive and may make the copy so deformed that it cannot do what it used to do and so cannot replicate or survive in that environment. Its likelihood of survival (being repeated) is decreased and it may not even last until the next copying takes place (it dies before reproducing). But every once in a great while the mistake is an improvement to the original information base (design); it is useful for the organism and its function. It conforms better to reality. And so it is more likely to get replicated and retained again than the original version. The beneficial error need only be 1% of all mistakes – that’s enough for evolution to occur over multiple replications. And it will eventually result in improvements in the previous design. That is because this new, more useful information (mutations) is replicated more often over time than the original version. For instance, at the genetic level, mutations can occur in the sequences of information coded in the DNA and these mistakes can have effects on the functioning of that DNA. If those mistakes improve functioning they are likely to get replicated again. Overtime, its copies will out-survive and out-reproduce the original versions and so replace those of the original version from which it mutated. And so on.

(6) There is a Selecting Environment: For information to exist, it must exist some where. That “where” is physical reality – the natural world. It is often called the environment but that just means a local region of reality. Every specific environment in which information may exist and accumulate by evolution has specific characteristics that make it different from every other specific situation or setting. Some aspect of the environment affects the likelihood that some copies will survive while others may be less fit and so destroyed in that environment. In this way, one or more specific characteristics of the environment serve as a mechanism for selection. This is why genetic evolution is called natural selection. There is no intention being exercised here in creating the information – there is no grand designer guiding the process. If the environment has absolutely no feature that has any influence on the survival of the copies, then no evolution will take place other than the eventual piling-up of mistakes over time in subsequent copies. If this goes on long enough, copying may no longer be possible. The information base is then in a sense dead; it is merely junk. But this is unlikely because specific settings often do have specific features that are going to have some effect, even if a small one, on which copies have a better chance of being replicated the next time around compared to other copies. Combined with imperfect copying discussed above, the environment by its very nature selects the information (knowledge) that best conforms to it among the variations in the information copies that may exist. It does so by adversely affecting the copies that are not as conforming. Over repeated trials the information becomes closer and closer to conforming to reality (accuracy or truth value) with each trial. To the extent that environmental features have any effect on the copying process, they are acting (blindly) to select some strings or forms of information over others in the information base that get to survive and reproduce again.

(7) The Environment Criticizes or Judges the Conformity of the Information to It. Inherent in all material reality is this capacity to have an adverse shaping or selective influence on any information that is being stored, copied, and thus tested within that environment. The environment doesn’t actually choose the good copies but selectively acts to eliminate those less fit or suited to that environment. It is a negative influence – a culling of the less fit. By default, the copies that remain are better suited to existing in that environment. This selecting out or culling function of the less fit copies by the environment can be thought of as Criticism. It is the negative feedback from the environment concerning whether the information being tested better conforms or not to that environment. The more it conforms, the more correct or accurate it is in modeling that environment; that is, the less the environment disagrees with it. The less it conforms, the more the environment disagrees with it. This is a comparative process indicating how well the information or knowledge being put forth from the storage device matches the environment. In a sense, it is about how well the information is modeling reality. In any particular trial, such criticism has the effect of making some versions of the information less likely to survive to the next trial. Criticism is simply disagreement. Here then is another secret to the development of all knowledge of the natural world anywhere in the universe – it must be criticized by its environment! The relatively less fit information is getting continuously removed by that environment such that the information that survives is a more accurate (better fitted) piece of information concerning that environment than were earlier versions of information.

(8) And There Should be Environmental Change: When something happens, (it could be nearly anything) that changes the environment from what it was previously, that is all that is needed for evolution to occur. In genetic evolution, this change in the original environment is the origin of new species emerging over repeated trials from older ones. This often happens when some members of a species migrate to a new environment. At other times it occurs when the environment undergoes some significant change for one subset of the species (copies of the information) but not others. In either case, new selection processes or pressures exist in the new environment that can differ from the prior one. These new features of the environment now provide new and different feedback than did the original environment. This new feedback is often called a selection pressure. It operates to guide or pressure evolution of that subset of organisms into a new path of evolution. The organisms (copies of information) may have been better adapted to the prior environment but their current form may now prove to be less suitable (conform) to the new one. If the change to the environment is too extreme, the organisms may not be able to survive at all. But if some do, and as mutations occur in them, some of those mutations may offer a better selective advantage for that organism to survive in that new environment. Over time, such beneficial mutations can cause enough change in the original species such that it becomes a new species (can no longer interbreed with members of the original one).

(9) Evolution Benefits from Intercourse – Exchanging Information with Others: Although biological evolution can occur without the exchange of genetic material between organisms, as was likely the case in the early stages of life on Earth, it benefits substantially from doing so. This explains why many species evolved sexual reproduction. By exchanging pieces of genetic information with other members of the species (or as with viruses, other species entirely) new information and especially new arrangements of that information enters the information base that did not previously reside there. Such exchanges of information allow the more rapid rate of occurrence of novel recombinations of that information, some of which are likely to prove more beneficial to survival and replication (reproduction) than the original combination. This usually occurs at the genetic level via sexual intercourse. But it need not be by sex as some asexual species of viruses and bacteria can give up and also collect pieces of genetic material from others with whom they physically interact.


Campbell, D. T. (1960). Blind variation and selective retention in creative thought as in other knowledge processes. Psychological Review 67: 380–400.

This blog is an adaptation and updating of material from R. A. Barkley (2012). Executive Functions: What They Are, How They Work, and Why They Evolved. New York: Guilford Press. ©Guilford Press, 2012. Adapted and reprinted with permission.

Dr. Barkley is a Clinical Professor of Psychiatry at the Virginia Commonwealth University Health Center and the Virginia Treatment Center for Children, Richmond, VA.