Evolution by Natural Experiment

This is the age of the evolution of Evolution. All thoughts that the Evolutionist works with, all theories and generalizations, have themselves evolved and are now being evolved. Even were his theory perfected, its first lesson would be that it was itself but a phase of the Evolution of other opinion, no more fixed than a species, no more final than the theory which it displaced.

— Henry Drummond, 1883

Charles Darwin described The Origin of Species as “one long argument” for evolution by natural selection. Subsequently Ernst Mayr applied the expression to the continuing debate over Darwin’s ideas. My explanation of why the debate lingers is that although Darwin was right about the reality of evolution, his causal theory was fundamentally wrong, and its errors have been compounded by neo-Darwinism. In 1985 my book Evolutionary Theory: The Unfinished Synthesis was published. In it I discussed Darwinian problems that have never been solved, and the difficulties suffered historically by holistic approaches to evolutionary theory. The most important of these holistic treatments was “emergent evolution,” which enjoyed a brief moment of popularity about 80 years ago before being eclipsed when natural selection was mathematically formalized by theoretical population geneticists. I saw that the concept of biological emergence could provide a matrix for a reconstructed evolutionary theory that might displace selectionism. At that time, I naively thought that there was a momentum in favor of such a revision, and that there were enough open-minded, structuralistic evolutionists to displace the selectionist paradigm within a decade or so. Faint hope! (Robert G. B. Reid. Biological Emergences: Evolution by Natural Experiment (Vienna Series in Theoretical Biology) (Kindle Locations 31-37). Kindle Edition.)

Instead, the conventional “Modern Synthesis” produced extremer forms of selectionism. Although some theoreticians were dealing effectively with parts of the problem, I decided I should try again, from a more general biological perspective. This book is the result. (Reid 2007, Preface)

The main thrust of the book is an exploration of evolutionary innovation, after a critique of selectionism as a mechanistic explanation of evolution. Yet it is impossible to ignore the fact that the major periods of biological history were dominated by dynamic equilibria where selection theory does apply. But emergentism and selectionism cannot be synthesized within an evolutionary theory. A “biological synthesis” is necessary to contain the history of life. I hope that selectionists who feel that I have defiled their discipline might find some comfort in knowing that their calculations and predictions are relevant for most of the 3.5 billion years that living organisms have inhabited the Earth, and that they forgive me for arguing that those calculations and predictions have little to do with evolution. (Reid 2007, Preface)

Evolution is about change, especially complexifying change, not stasis. There are ways in which novel organisms can emerge with properties that are not only self-sufficient but more than enough to ensure their status as the founders of kingdoms, phyla, or orders. And they have enough generative potential to allow them to diversify into a multiplicity of new families, genera, and species. Some of these innovations are all-or-none saltations. Some of them emerge at thresholds in lines of gradual and continuous evolutionary change. Some of them are largely autonomous, coming from within the organism; some are largely imposed by the environment. Their adaptiveness comes with their generation, and their adaptability may guarantee success regardless of circumstances. Thus, the filtering, sorting, or eliminating functions of natural selection are theoretically redundant. (Reid 2007, Preface)

Therefore, evolutionary theory should focus on the natural, experimental generation of evolutionary changes, and should ask how they lead to greater complexity of living organisms. Such progressive innovations are often sudden, and have new properties arising from new internal and external relationships. They are emergent. In this book I place such evolutionary changes in causal arenas that I liken to a three-ring circus. For the sake of bringing order to many causes, I deal with the rings one at a time, while noting that the performances in each ring interact with each other in crucial ways. One ring contains symbioses and other kinds of biological association. In another, physiology and behavior perform. The third ring contains of developmental or epigenetic evolution. (Reid 2007, Preface)

After exploring the generative causes of evolution, I devote several chapters to subtheories that might arise from them, and consider how they might be integrated into a thesis of emergent evolution. In the last chapter I propose a biological synthesis. (Reid 2007, Preface)

~ ~ ~

Introduction Re-Invention of Natural Selection

I regard it as unfortunate that the theory of natural selection was first developed as an explanation for evolutionary change. It is much more important as an explanation for the maintenance of adaptation.
George Williams, 1966

Natural selection cannot explain the origin of new variants and adaptations, only their spread.
John Endler, 1986

We could, if we wished, simply replace the term natural selection with dynamic stabilization….
Brian Goodwin, 1994

Nobody is going to re-invent natural selection….
Nigel Hawkes, 1997

Ever since Charles Darwin published The Origin of Species, it has been widely believed that natural selection is the primary cause of evolution. However, while George Williams and John Endler take the trouble to distinguish between the causes of variation and what natural selection does with them; the latter is what matters to them. In contrast, Brian Goodwin does not regard natural selection as a major evolutionary force, but as a process that results in stable organisms, populations, and ecosystems. He would prefer to understand how evolutionary novelties are generated, a question that frustrated Darwin for all of his career. (Reid 2007)

During the twentieth century, Darwin’s followers eventually learned how chromosomal recombination and gene mutation could provide variation as fuel for natural selection. They also re-invented Darwinian evolutionary theory as neo-Darwinism by formalizing natural selection mathematically. Then they redefined it as differential survival and reproduction, which entrenched it as the universal cause of evolution. Nigel Hawkes’s remark that natural selection cannot be re-invented demonstrates its continued perception as an incorruptible principle. But is it even a minor cause of evolution? (Reid 2007)

Natural selection supposedly builds order from purely random accidents of nature by preserving the fit and discarding the unfit. On the face of it, that makes more than enough sense to justify its importance. Additionally, it avoids any suggestion that a supernatural creative hand has ever been at work. But it need not be the only mechanistic option. And the current concept of natural selection, which already has a history of re-invention, is not immune to further change. Indeed, if its present interpretation as the fundamental mechanism of evolution were successfully challenged, some of the controversies now swirling around the modern paradigm might be resolved. (Reid 2007)

A Paradigm in Crisis?

Just what is the evolutionary paradigm that might be in crisis? It is sometimes called “the Modern Synthesis.” Fundamentally it comes down to a body of knowledge, interpretation, supposition, and extrapolation, integrated with the belief that natural selection is the all-sufficient cause of evolutionif it is assumed that variation is caused by gene mutations. The paradigm has built a strong relationship between ecology and evolution, and has stimulated a huge amount of research into population biology. It has also been the perennial survivor of crises that have ebbed and flowed in the tide of evolutionary ideas. Yet signs of discord are visible in the strong polarization of those who see the whole organism as a necessary component of evolution and those who want to reduce all of biology to the genes. Since neo-Darwinists are also hypersensitive to creationism, they treat any criticism of the current paradigm as a breach of the scientific worldview that will admit the fundamentalist hordes. Consequently, questions about how selection theory can claim to be the all-sufficient explanation of evolution go unanswered or ignored. Could most gene mutations be neutral, essentially invisible to natural selection, their distribution simply adrift? Did evolution follow a pattern of punctuated equilibrium, with sudden changes separated by long periods of stasis? Were all evolutionary innovations gene-determined? Are they all adaptive? Is complexity built by the accumulation of minor, selectively advantageous mutations? Are variations completely random, or can they be directed in some way? Is the generation of novelty not more important than its subsequent selection? (Reid 2007)

Long before Darwin, hunters, farmers, and naturalists were familiar with the process that he came to call “natural selection.” And they had not always associated it with evolution. It is recognized in the Bible, a Special Creation text. Lamarck had thought that evolution resulted from a universal progressive force of nature, not from natural selection. Organisms responded to adaptational needs demanded by their environments. The concept of adaptation led Lamarck’s rival, Georges Cuvier, to argue the opposite. If existing organisms were already perfectly adapted, change would be detrimental, and evolution impossible. Nevertheless, Cuvier knew that biogeography and the fossil record had been radically altered by natural catastrophes. These Darwin treated as minor aberrations during the long history of Earth. He wanted biological and geographical change to be gradual, so that natural selection would have time to make appropriate improvements. The process of re-inventing the events themselves to fit the putative mechanism of change was now under way. (Reid 2007)

Gradualism had already been brought to the fore when geologists realized that what was first interpreted as the effects of the sudden Biblical flood was instead the result of prolonged glaciation. Therefore, Darwin readily fell in with Charles Lyell’s belief that geological change had been uniformly slow. Now, more than a century later, catastrophism has been resurrected by confirmation of the K-T (Cretaceous-Tertiary) bolide impact that ended the Cretaceous and the dinosaurs. Such disasters are also linked to such putative events as the Cambrian “Big Bang of Biology,” when all of the major animal phyla seem to have appeared almost simultaneously.’ The luck of the draw has returned to evolutionary theory. Being in the right place at the right time during a cataclysm might have been the most important condition of survival and subsequent evolution. (Reid 2007)

Beyond the fringe of Darwinism, there are heretics who believe the neo-Lamarckist tenet that the environment directly shapes the organism in a way that can be passed on from one generation to the next. They argue that changes imposed by the environment, and by the behavior of the organism, are causally prior to natural selection. Nor is neo-Lamarckism the only alternative. Some evolutionary biologists, for example, think that the establishment of unique symbioses between different organisms constituted major evolutionary novelties. Developmental evolutionists are reviewing the concept that evolution was not gradual but saltatory (i.e., advancing in leaps to greater complexity). However, while they emphasize the generation of evolutionary novelty, they accommodate natural selection as the complementary and essential causal mechanism. (Reid 2007)

Notes on isms

Before proceeding further, I want to explain how I arbitrarily, but I hope consistently, use the names that refer to evolutionary movements and their originators. “Darwinian” and “Lamarckian” refer to any idea or interpretation that Darwin and Lamarck originated or strongly adhered to. Darwinism is the paradigm that rose from Darwinian concepts, and Lamarckism is the movement that followed Lamarck. They therefore include ideas that Darwin and Lamarck may not have thought of nor emphasized, but which were inspired by them and consistent with their thinking. Lamarck published La philosophie zoologique in 1809, and Lamarckism lasted for about 80 years until neo-Lamarckism developed. Darwinism occupied the time frame between the publication of The Origin of Species (1859) and the development of neo-Darwinism. The latter came in two waves. The first was led by August Weismann, who was out to purify evolutionary theory of Darwinian vacillation. The second wave, which arose in theoretical population genetics in the 1920s, quantified and redefined the basic tenets of Darwinism. Selectionism is the belief that natural selection is the primary cause of evolution. Its influence permeates the Modern Synthesis, which was originally intended to bring together all aspects of biology that bear upon evolution by natural selection. Niles Eldredge (1995) uses the expression “ultra-Darwinian” to signify an extremist position that makes natural selection an active causal evolutionary force. For grammatical consistency, I prefer “ultra-Darwinist,” which was used in the same sense by Pierre-Paul Grasse in 1973. (Reid 2007)

The Need for a More Comprehensive Theory

I have already hinted that the selectionist paradigm is either insufficient to explain evolution or simply dead wrong. Obviously, I want to find something better. Neo-Darwinists themselves concede that while directional selection can cause adaptational change, most natural selection is not innovative. Instead, it establishes equilibrium by removing extreme forms and preserving the status quo. John Endler, the neo-Darwinist quoted in one of this chapter’s epigraphs, is in good company when he says that novelty has to appear before natural selection can operate on it. But he is silent on how novelty comes into being, and how it affects the internal organization of the organismquestions much closer to the fundamental process of evolution. He is not being evasive; the issue is just irrelevant to the neo-Darwinist thesis. (Reid 2007)

Darwin knew that nature had to produce variations before natural selection could act, so he eventually co-opted Lamarckian mechanisms to make his theory more comprehensive. The problem had been caught by other evolutionists almost as soon as The Origin of Species was first published. Sir Charles Lyell saw it clearly in 1860, before he even became an evolutionist:

If we take the three attributes of the deity of the Hindoo Triad, the Creator, Brahmah, the preserver or sustainer, Vishnu, & the destroyer, Siva, Natural Selection will be a combination of the two last but without the first, or the creative power, we cannot conceive the others having any function.

Consider also the titles of two books: St. George Jackson Mivart’s On the Genesis of Species (1872) and Edward Cope’s Origin of the Fittest (1887). Their play on Darwin’s title emphasized the need for a complementary theory of how new biological phenomena came into being. Soon, William Bateson’s Materials for the Study of Variation Treated with Especial Regard to Discontinuity in the Origin of Species (1894) was to distinguish between the emergent origin of novel variations and the action of natural selection. (Reid 2007)

The present work resumes the perennial quest for explanations of evolutionary genesis and will demonstrate that the stock answerpoint mutations and recombinations of the genes, acted upon by natural selectiondoes not suffice. There are many circumstances under which novelties emerge, and I allocate them to arenas of evolutionary causation that include association (symbiotic, cellular, sexual, and social), functional biology (physiology and behavior), and development and epigenetics. Think of them as three linked circus rings of evolutionary performance, under the “big top” of the environment. Natural selection is the conservative ringmaster who ensures that tried-and-true traditional acts come on time and again. It is the underlying syndrome that imposes dynamic stabilityits hypostasis (a word that has the additional and appropriate meaning of “significant constancy”). (Reid 2007)

Selection as Hypostasis

The stasis that natural selection enforces is not unchanging inertia. Rather, it is a state of adaptational and neutral flux that involves alterations in the numerical proportions of particular alleles and types of organism, and even minor extinctions. It does not produce major progressive changes in organismal complexity. Instead, it tends to lead to adaptational specialization. Natural selection may not only thwart progress toward greater complexity, it may result in what Darwin called retrogression, whereby complex and adaptable organisms revert to simplified conditions of specialization. This is common among parasites, but not unique to them. For example, our need for ascorbic acid-vitamin C-results from the regression of a synthesis pathway that was functional in our mammalian ancestors. (Reid 2007)

On the positive side, it may be argued that dynamic stability, at any level of organization, ensures that the foundations from which novelties emerge are solid enough to support them on the rare occasions when they escape its hypostasis. A world devoid of the agents of natural selection might be populated with kludges-gimcrack organisms of the kind that might have been designed by Heath Robinson, Rube Goldberg, or Tim Burton. The enigmatic “bizarre and dream-like” Hallucigenia of the Burgess Shale springs to mind.’ Even so, if physical and embryonic factors constrain some of the extremest forms before they mature and reproduce, the benefits of natural selection are redundant. Novelty that is first and foremost integrative (i.e., allows the organism to operate better as a whole) has a quality that is resistant to the slings and arrows of selective fortune. (Reid 2007)

Natural selection has to do with relative differences in survival and reproduction and the numerical distribution of existent variations that have already evolved. In this form it requires no serious re-invention. But selectionism goes on to infer that natural selection creates complex novelty by saving adaptive features that can be further built upon. Such qualities need no saving by metaphorical forces. Having the fundamental property of persistence that characterizes life, they can look after themselves. As Ludwig von Bertalanffy remarked in 1967, “favored survival of `better’ precursors of life presupposes self-maintaining, complex, open systems which may compete; therefore natural selection cannot account for the origin of those symptoms.” These qualities were in the nature of the organisms that first emerged from non-living origins, and they are prior to any action of natural selection. Compared to them, ecological competitiveness is a trivial consequence. (Reid 2007)

But to many neo-Darwinists the only “real” evolution is just that: adaptationthe selection of random genetic changes that better fit the present environment. Adaptation is appealingly simple, and many good little examples crop up all the time. However, adaptation only reinforces the prevailing circumstances, and represents but a fragment of the big picture of evolution. Too often, genetically fixed adaptation is confused with adaptabilitythe self-modification of an individual organism that allows responsiveness to internal and external change. The logical burden of selectionism is compounded by the universally popular metaphor of selection pressure, which under some conditions of existence is supposed to force appropriate organismic responses to pop out spontaneously. How can a metaphor, however heuristic, be a biological cause? As a metaphor, it is at best is an inductive guide that must be used with caution. (Reid 2007)

Even although metaphors cannot be causes, their persuasive powers have given natural selection and selection pressure perennial dominance of evolutionary theory. It is hard enough to sideline them, so as to get to generative causes, far less to convince anyone that they are obstructive. Darwin went so far as to make this admission:

In the literal sense of the word, no doubt, natural selection is a false term…. It has been said that I speak of natural selection as an active power or Deity…. Everyone knows what is meant and is implied by such metaphorical expressions; and they are almost necessary for brevity…. With a little familiarity such superficial objections will be forgotten. [Darwin 1872, p. 60.]

Alas, in every subsequent generation of evolutionists, familiarity has bred contempt as well as forgetfulness for such “superficial” objections. (Reid 2007)

Are All Changes Adaptive?

Here is one of my not-so-superficial objections. The persuasiveness of the selection metaphor gets extra clout from its link with the vague but pervasive concept of adaptiveness, which can supposedly be both created and preserved by natural selection. For example, a book review insists that a particular piece of pedagogy be “required reading for non-Darwinist `evolutionists’ who are trying to make sense of the world without the relentless imperatives of natural selection and the adaptive trends it produces.” (Reid 2007)

Adaptiveness, as a quality of life that is “useful,” or competitively advantageous, can always be applied in ways that seem to make sense. Even where adaptiveness seems absent, there is confidence that adequate research will discover it. If equated with integrativeness, adaptiveness is even a necessity of existence. The other day, one of my students said to me: “If it exists, it must have been selected.” This has a pleasing parsimony and finality, just like “If it exists it must have been created.” But it infers that anything that exists must not only be adaptive but also must owe its existence to natural selection. I responded: “It doesn’t follow that selection caused its existence, and it might be truer to say ‘to be selected it must first exist.”‘ A more complete answer would have addressed the meaning of existence, but I avoid ontology during my physiology course office hours. (Reid 2007)

“Adaptive,” unassuming and uncontroversial as it seems, has become a “power word” that resists analysis while enforcing acceptance. Some selectionists compound their logical burden by defining adaptiveness in terms of allelic fitness. But there are sexually attractive features that expose their possessors to predation, and there are “Trojan genes” that increase reproductive success but reduce physiological adaptability. They may be the fittest in terms of their temporarily dominant numbers, but detrimental in terms of ultimate persistence. (Reid 2007)

It is more logical to start with the qualities of evolutionary changes. They may be detrimental or neutral. They may be generally advantageous (because they confer adaptability), or they may be locally advantageous, depending on ecological circumstances. Natural selection is a consequence of advantageous or “adaptive” qualities. Therefore, examination of the origin and nature of adaptive novelty comes closer to the fundamental evolutionary problem. It is, however, legitimate to add that once the novel adaptive feature comes into being, any variant that is more advantageous than other variants survives differentiallyif under competition. Most biologists are Darwinists to that extent, but evolutionary novelty is still missing from the causal equation. Thus, with the reservation that some neutral or redundant qualities often persist in Darwin’s “struggle for existence,” selection theory seems to offer a reasonable way to look at what occurs after novelty has been generatedthat is, after evolution has happened. (Reid 2007)

“Oh,” cry my student inquisitors, “but the novelty to which you refer would be meaningless if it were not for correlated and necessary novelties that natural selection had already preserved and maintained.” So again I reiterate first principles: Self-sustaining integrity, an ability to reproduce biologically, and hence evolvability were inherent qualities of the first living organisms, and were prior to differential survival and reproduction. They were not, even by the lights of extreme neo-Darwinists, created by natural selection. And their persistence is fundamental to their nature. To call such features adaptive, for the purpose of implying they were caused by natural selection, is sophistry as well as circumlocution. Sadly, many biologists find it persuasive. Ludwig von Bertalanffy (1952) lamented:

Like a Tibetan prayer wheel, Selection Theory murmurs untiringly: ‘everything is useful,’ but as to what actually happened and which lines evolution has actually followed, selection theory says nothing, for the evolution is the product of ‘chance,’ and therein obeys no ‘law. [Bertalanffy 1952, p. 92.]

In The Variation of Animals in Nature (1936), G. C. Robson and O. W. Richards examined all the major known examples of evolution by natural selection, concluding that none were sufficient to account for any significant taxonomic characters. Despite the subsequent political success of ecological genetics, some adherents to the Modern Synthesis are still puzzled by the fact that the defining characteristics of higher taxa seem to be adaptively neutral. For example, adult echinoderms such as sea urchins are radially symmetrical, i.e., they are round-bodied like sea anemones and jellyfish, and lack a head that might point them in a particular direction. This shape would seem to be less adaptive than the bilateral symmetry of most active marine animals, which are elongated and have heads at the front that seem to know where they want to go. Another puzzler: How is the six-leg body plan of insects, which existed before the acquisition of wings, more or less adaptive than that of eight-legged spiders or ten-legged legged lobsters? The distinguished neo-Darwinists Dobzhansky, Ayala, Stebbins, and Valentine (1977) write:

This view is a radical deviation from the theory that evolutionary changes are governed by natural selection. What is involved here is nothing less than one of the major unresolved problems of evolutionary biology. []

The problem exists only for selectionists, and so they happily settle for the first plausible selection pressure that occurs to them. But it could very well be that insect and echinoderm and jellyfish body plans were simply novel complexities that were consistent with organismal integritythey worked. There is no logical need for an arbiter to judge them adaptive after the fact.

Some innovations result from coincidental interactions between formerly independent systems. Natural selection can take no credit for their origin, their co-existence, or their interaction. And some emergent novelties often involve redundant features that persisted despite the culling hand of nature. Indeed, life depends on redundancy to make evolutionary experiments. Initially selectionism strenuously denies the existence of such events. When faced with the inevitable, it downplays their importance in favor of selective adjustments necessary to make them more viable. Behavior is yet another function that emphasizes the importance of the whole organism, in contrast to whole populations. Consistent changes in behavior alter the impact of the environment on the organism, and affect physiology and development. In other words, the actions of plants or animals determine what are useful adaptations and what are not. This cannot even be conceived from the abstract population gene pools that neo-Darwinists emphasize.

If some evolutionists find it easier to understand the fate of evolutionary novelty through the circumlocution of metaphorical forces, so be it. But when they invent such creative forces to explain the origin of evolutionary change, they do no better than Special Creationists or the proponents of Intelligent Design. Thus, the latter find selectionists an easy target. Neo-Darwinist explanations, being predictive in demographic terms, are certainly “more scientific” than those of the creationists. But if those explanations are irrelevant to the fundamentals of evolution, their scientific predictiveness is of no account.

What we really need to discover is how novelties are generated, how they integrate with what already exists, and how new, more complex whole organisms can be greater than the sums of their parts. Evolutionists who might agree that these are desirable goals are only hindered by cant about the “relentless imperatives of natural selection and the adaptive trends it produces.”

(….) Reductionism

Reduction is a good, logical tool for solving organismal problems by going down to their molecular structure, or to physical properties. But reductionism is a philosophical stance that embraces the belief that physical or chemical explanations are somehow superior to biological ones. Molecular biologists are inclined to reduce the complexity of life to its simplest structures, and there abandon the quest. “Selfish genes” in their “gene pools” are taken to be more important than organisms. To compound the confusion, higher emergent functions such as intelligence and conscious altruism are simplistically defined in such a way as to make them apply to the lower levels. This is reminiscent of William Livant’s (1998) “cure for baldness”: You simply shrink the head to the degree necessary for the remaining hair to cover the entire patethe brain has to be shrunk as well, of course. This “semantic reductionism” is rife in today’s ultra-Darwinism, a shrunken mindset that regards evolution as no more than the differential reproduction of genes.

Although reducing wholes to their parts can make them more understandable, fascination with the parts makes it too easy to forget that they are only subunits with no functional independence, whether in or out of the organism. It is their interactions with higher levels of organization that are important. Nevertheless, populations of individuals are commonly reduced to gene pools, meaning the totality of genes of the interbreeding organisms. Originating as a mathematical convenience, the gene pool acquired a life of its own, imbued with a higher reality than the organism. Because genes mutated to form different alleles that could be subjected to natural selection, it was the gene pool of the whole population that evolved. This argument was protected by polemic that decried any reference to the whole organism as essentialistic. Then came the notion that genes have a selfish nature. Even later, advances in molecular biology, and propaganda for the human genome project, have allowed the mistaken belief that there must be a gene for everything, and once the genes and their protein products have been identified that’s all we need to know. Instead, the completion of the genome project has clearly informed us that knowing the genes in their entirety tells us little about evolution. Yet biology still inhabits a genocentric universe, and most of its intellectual energy and material resources are sucked in by the black hole of reductionism at its center.

(….) Epigenetic Algorithms

Mechanical metaphors have appealed to many philosophers who sought materialist explanations of life. The definitive work on this subject is T. S. Hall’s Ideas of Life and Matter (1969). Descartes, though a dualist, thought of animal bodies as automata that obeyed mechanical rules. Julien de la Mettrie applied stricter mechanistic principles to humans in LʼHomme machine (1748). Clockwork and heat engine models were popular during the Industrial Revolution. Lamarck proposed hydraulic processes as causes of variation. In the late nineteenth century, the embryologists Wilhelm His and Wilhelm Roux theorized about developmental mechanics. However, as biochemical and then molecular biological information expanded, popular machine models were refuted, but it is not surprising that computers should have filled the gap. Algorithms that systematically provide instructions for a progressive sequence of events seem to be suitable analogues for epigenetic procedures.

A common error in applying this analogy is the belief that the genetic code, or at least the total complement of an organism’s DNA contains the program for its own differential expression. In the computer age it is easy to fall into that metaphysical trap. However, in the computer age we should also know that algorithms are the creations of programmers. As Charles Babbage (1838) and Robert Chambers (1844) tried to tell us, the analogy is more relevant to creationism than evolutionism. At the risk of offending the sophisticates who have indulged me so far, I want to state the problems in the most simple terms. To me, that is a major goal of theoretical biology, rather than the conversion of life to mathematics. (Robert G. B. Reid. Biological Emergences: Evolution by Natural Experiment (Vienna Series in Theoretical Biology) (p. 263). Kindle Edition.)

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