1859, the year of publication of Darwin’s The Origin of Species, was the year that the concept of evolution exploded into popular consciousness. It went on to foment a controversy that raged for a hundred years and still continues, in some quarters, to be considered problematic. That was because Darwin, and independently Alfred Wallace, had proposed a mechanism, natural selection, for the evolution of species that did not require the intervention of a divine creator, in what was considered to be an overwhelmingly Christian country.
The idea of an evolutionary development of biological forms was hardly new. Its first known expression was in the Greek Presocratic philosopher Anaximander (c.610-546) but based on purely rationalistic speculation. Many others throughout history proposed some form of evolutionary development, in both nature and society, intuiting some form of morphological or societal continuity. What Darwin did was unique: he took the detailed observations of phenotypical variation he had gathered during his three-year voyage on HMS Beagle and linked that to his knowledge of the practices of animal breeders, to arrive at the idea of natural selection, that is a process by which nature – rather than a human agent – selected the traits which were most desirable under prevailing local environmental conditions.
The wider context, and the subject of this essay, is that Darwin did not articulate his theory in an intellectual vacuum, nor did he theorise into one. Evolutionary theory has itself undergone a transformation that we can refer to as evolutionary. The idea of evolution, as the title of Depew and Weber’s (1995) book, Darwinism Evolving, makes the point, has itself evolved, from the basic natural selection of Darwin’s own time to neo-Darwinism or the “modern synthesis” of natural selection with Mendelian genetics, to the modern iterations of complex systems theory, and new fields of study such as epigenetics and horizontal gene transfer. Each development has challenged some aspect of the central dogmas of Darwinism and extended the meaning of evolution, though in the end even theories that have sought to supplant natural selection, such as complexity, have actually enriched the idea (Wilson, 2009).
However, the argument made here is that evolutionary theory is not simply a matter of fact but a form of discourse that triangulates between naturalistic and experimental observation, philosophical speculation, including on the course of societal development and linguistic innovation, particularly the implementation of analogy but also metaphor.
There is a long history of speculative evolutionary theory to which Darwin was heir. Charles Lyell, one of the most famous and influential geologists of the nineteenth century, whose books were known to Darwin and were standard geological texts well into the twentieth century, advanced an evolutionary theory based on his observations of the fossil record. Post The Origin of Species, a contemporary of Darwin, Herbert Spencer, took the idea of natural selection and applied it to human society, creating Social Darwinism and coined the phrase “the survival of the fittest” in his book The Principles of Biology (1864), a phrase that Darwin had not used, but of which he approved and which has come for many to epitomise the idea of Darwinian evolution.
The term ‘evolution’ comes from the Latin evolere meaning ‘to unroll’ and has taken on the sense of a continuous process of transformation or opening out. This is why it is often used as a synonym for ‘change’ or ‘transformation’. But the idea of evolution has also acquired something of an evaluative meaning of ‘development’ or ‘progress’ through the observation that things have become more complex over time. The notion of progress is a peculiarly human notion that things change for the better, or at least should do, although we might fight over what ‘better’ means in any specific case. In the social context, therefore, the idea of evolution has taken on a teleological connotation of moving towards a goal. It is not a coincidence that Darwin’s theory was developed in the nineteenth century in Britain, which was at the height of its power and was going through an extraordinary period of social, economic and political transformation in which the idea of progress was very much to the fore.
Though we know Darwin did not see natural selection in these terms, one could argue that the notions of progress and agency are already encoded in the concept of natural selection; just as the pigeon or dog breeder is actively selecting for the preferred characteristics in the breed, it is difficult not to transfer these notions of preference and agency to the forces of nature and generations of evolutionary thinkers have struggled manfully – usually unsuccessfully – to avoid imputing anthropomorphic tendencies to nature in their choice of metaphors for variation and adaptation. Richard Dawkins is well known for his metaphor of the ‘blind watchmaker’, referencing William Paley’s argument from design, yet the metaphor gains its power precisely because, by sleight-of-hand, it invokes the agency of the watchmaker while simultaneously denying that agency. To be descriptively accurate our watchmaker would have to be not merely sans eyes but also sans hands and sans brain, in which case not a watchmaker at all.
Since the implication of Darwin’s theory of evolution by natural selection became obvious, there has been an attempt to purge evolutionary thinking of its anthropomorphising of nature and present it as pure mechanism. There is no doubt that the rediscovery in 1900 of Gregor Mendel’s 1865 work on the recombination of inherited traits, through his experimentation with pea varieties, and its synthesis with natural selection (neo-Darwinism) brought the holy grail of testable mechanism of evolution closer. What it did do was to lay to rest Lamarck’s theory of inheritance of acquired characteristics as an alternative to natural selection and to provide a deeper level of understanding of the mechanism of variability and inheritance which led to the development of population genetics. What it could not account for, at the macroevolutionary level, was the proposed transition from one form of life to another. Once more, metaphor was called into play with, for example Goldschmidt’s theory of ‘hopeful monsters’ to account for the emergence of phenotypic novelty. Once again, in order to generate an explanatory mechanism based on the then state of knowledge, a scientist was forced to anthropomorphise nature, which demonstrates how difficult it is to escape from the conceptual language of intention.
Interestingly, Havstadt (2011, p.512) lists all the characterisations of natural selection in The Origin of Species, such as “an action,… a doctrine,… a means,… a power,… a principle,… a process,… and a theory”, but there is no mention of Darwin referring to it as a mechanism (ibid.). It is only later commentators, such as Ernst Mayr, who introduce the idea of natural selection as a mechanism. Havstadt, though, makes a strong case that the very variability of adaptive processes within nature make the argument for a single generalised mechanism untenable, as it would have to be extended to non-natural selective processes (ibid.), rather than one limited to biological contexts.
Darwin’s theory seemed elegantly simple at the time, as it seems so to us today. The basic idea that most people are familiar with is that of random variation that confers survival advantages that is then inherited by future generations, so-called (though not originally by Darwin) ‘survival of the fittest’ though properly referred to as evolution by natural selection. A number of scientific and philosophical arguments have been made against natural selection. It has been a longstanding view that “survival of the fittest” is tautological; Karl Popper pointed out its supposed unfalsifiability, which led him to refer to it as a “metaphysical research programme” rather than a scientific theory, that is to say, a hypothesis that encompasses a view of the world and directs the research of scientists across many disciplines but for which no direct evidence exists. This view has always been considered one of Popper’s – considered by many to be the foremost philosopher of science of the twentieth century – most controversial ideas. Yet, this seems close to what I am proposing here, which is that evolution is an idea which is always in flux, caught in the interplay between actual observation, theory, social policy and culture, but for which a thorough causal explanation is tantalisingly just out of reach.
One scientist who had no issue with a thoroughgoing metaphysics of evolution was the Jesuit and co-discoverer of Peking Man, homo erectus pekinensis, Pierre Teilhard de Chardin. In The Phenomenon of Man (1959) Teilhard laid out his philosophy of the divine unrolling of evolution in nature and human history through the principles of radiation and individuation, leading to an ‘omega point’ at which the divine and human become one. Once feted by leading lights of evolution such as Julian Huxley, today no one takes Teilhard’s theories seriously as scientific explanation. However, he was heir to a tradition of philosophical evolutionism that includes G. F. W. Hegel, T. H. Green and Samuel Alexander and, as I have argued in two previous essays, an exponent of an alternative to secular humanism and the culture of disenchantment. A Teilhardian interpretation of human destiny has recently emerged in some futurist circles, who see in the concept of the omega point a metaphor for the point at which human consciousness and advanced AI merge.
The population genetics of this period, as well as being the paradigm within which evolutionary biology worked during the early to middle part of the twentieth century, also had a profound and troubling impact on social theory and practice through the eugenics movement. Eugenics, meaning ‘good breeding’, grew directly out of the application of the concept of the survival of the fittest to a policy of improvement of the human race, by scientific means it claimed. This was to be achieved by encouraging those with desirable traits to breed and discouraging those considered physically or mentally unfit. The eugenics movement, founded by Francis Galton, a cousin of Darwin, gained a degree of popularity in Britain among the political, artistic and intellectual elites. It sought to achieve this through education and social policy, but the rise of compulsory sterilisation in Nazi Germany led to its gradual rejection in Britain. Nevertheless, forms of involuntary eugenics continued to exist in the United States and Sweden several decades after the end of WW2.
If the modern synthesis seemed to have reached an impasse by the middle of the twentieth century, a new chapter opened up with the discovery of the structure of DNA and its subsequent recognition as the fundamental molecular basis of all living forms. Although there has been much ink spilled in recent years over the lack of recognition of the observational work of Rosalind Franklin emerging from her X-Rays of the crystal structure of DNA, upon which Francis Crick and James Watson constructed their model of DNA as the iconic double helix in 1953, for which they and Maurice Wilkins, but not Franklin, won the 1962 Nobel prize (Cobb & Comfort, 25 April 2023), there has been only scant recognition that the motifs of the helix, symbolised by entwined serpents, has been at the basis of almost every culture’s conception of the origin of life, together with associated symbolism to which DNA has been compared, such as twins, a ladder and a tree. Though highly speculative, the anthropologist Jeremy Narby, who spent years among the shamans of the Amazon, noted the prevalence of snake symbolism in shamanistic lore and visual art of every culture, which he hypothesised could be the result of awareness of the nature of DNA – or at least its figurative representation – during altered states of consciousness under the influence of hallucinogens (Narby, 1999). These symbols, somewhat recast, also find their way into the story of origins in the book of Genesis, from which myth research into human origins in the last few years has drawn on with the idea of the ‘mitochondrial Eve’, the female ancestor of every living human today. This ‘Eve’ is not the first human ancestor, just the first with a continuous female lineage down to the present day.
The evolutionary theorist Ernst Mayr (1985) argued that Darwinism, rather than a single theory, encapsulates five separate theories: continuous change; a common ancestor for all species; speciation, or the splitting of populations into separate species; gradualism; and natural selection. The first three of these are largely uncontroversial these days as the physical evidence (through DNA and the fossil record) supporting them is very strong and well-established. I want to focus on the latter two, gradualism and natural selection, as more interesting from the perspective of the argument being made here.
Gradualism is an extension of the assumption that scientific laws are the same in every place and time to changes over time, specifically to the development of life on earth, which states the process of speciation, the radiation of all extinct and extant life forms from a common ancestor, has occurred through continuous, incremental and non-directed change. This was seen as a conscious departure from the biblically-based ideas of divine creation and deluge. We have already considered one deviation from this belief, that of Goldsmith’s ‘hopeful monster’. In the 1970s Niles Eldredge and Stephen Jay Gould looked again at the blatant discontinuities of the fossil record and put forward a theory known as ‘punctuated equilibrium’ which hypothesises long periods of gradual change interspersed with periods of extremely rapid change (by geological standards) initiated by catastrophic environmental events Gould & Eldredge, 1977). Gould popularised the idea in a series of vignettes on notable geological cataclysms. What cannot be completely discounted is Gould’s philosophical commitment to Marxism, with its ideas of class conflict and violent revolution. Engels, Marx’s collaborator, in particular, outlined a dialectics of nature, including the principle of the transformation of a change in quality to a change in quality, a strikingly close analogue of punctuated equilibrium.
One cul-de-sac into which gradualism strayed is sometimes known as panevolutionism, the idea that the entire history of the universe can be understood in evolutionary, i.e., Darwinian, terms. Exemplified in the thinking of Jacques Monod and, to a large extent, Richard Dawkins, this is an example of the fundamentalism into which all types of beliefs can fall. Contemporary evolutionists are more willing to consider that there may be more principles at work in the evolutionary process. Some of those point to the seminal work on morphogenesis by D’Arcy Thompson in the early twentieth century, which indicate that there are physical parameters that seem to constrain the forms that biological entities can manifest. This has given rise to a whole new language in complex systems theory, that of “phase space”, “emergent forms”, “strange attractors” and “fitness landscapes”, and set off a search for the physico-chemical mechanism by which life could spontaneously emerge.
There have been a number of challenges to natural selection as the sole explanation for the development of life. Even Darwin himself was aware of the limits of natural selection as an explanation of phenotypic change and proposed an alternative, or at least parallel, explanation, that of sexual selection. According to sexual selection individual creatures may develop features such as elaborate plumage that may compromise their individual survival but assist them in attracting mates, which means those features are going to be inherited. The challenges are not so much to do with the principle of variation and adaptation as such; even the most diehard evolutionary sceptics accept that that is taking place. But these are evolution within a phenotype. What is highly problematic for the Darwinian perspective is the emergence within very short periods on the geological scale of multiple body forms and the populating of ecological niches, such as in the Pre-Cambrian explosion.
There are at least three serious challenges to natural selection. The first is the point already referred to, its tautological nature. The criticism amounts to the charge that evolution through natural selection amounts to little more than stating that whatever survives must be by definition the fittest, so fitness and survivability are mutually defining. This criticism has been somewhat circumvented by taking a contextual perspective, that of local adaptation rather than global conquest.
The second is palaeontological. The fossil evidence to support gradualism does not exist, which is why theories such as the ‘hopeful monster’ and punctuated equilibrium have arisen. Given the relative rarity of fossils, it is hardly surprising that a full audit trail is not available, and some intermediate forms have been found, so the criticism is something of a reductio ad absurdam. However, the biggest gap of all remains, the emergence of life itself, which is why a route to the spontaneous emergence of a simple life form from initial conditions remains the holy grail of biochemistry.
The third is mathematical. Given the extremely low probability of any mutation being beneficial to an organism, there is simply not enough time, even on geological timescales, for complex fully functional life forms to emerge. The rejoinder to this is that had this highly improbable sequence of events not occurred, we would not be here to argue about it, so the point is invalid. This rejoinder falls into the category of post hoc fallacy. The concept of intelligent design has been mooted to account for the seemingly insurmountable issue of (im)probability. This has attractions from a rationalist perspective but fails to gain any empirical traction and, moreover, fails to provide any testable mechanism other than human intuition. We await still a satisfactory scientific explanation for how evolution occurred at all scales.
Meanwhile, evolution through natural selection remains the best story we have of the emergence and development of life here on earth. I speak of it as a story, partly because it remains an unproven hypothesis in itself, though it has constituted a paradigm within which the life sciences have operated and inspired more than a century of scientific progress. It is a story, though, and one that has had dark moments, in its interweaving with philosophical ideas, political theory and the actions of governments. Its undermining of the biblical idea of creation removed one of the last pillars of belief in human exceptionalism and uniqueness, which, it can be argued, unleashed an indifference to humanity that justified all manner of barbarities that was one of the hallmarks of the twentieth century and one for which we have as yet no clear philosophical response. At the same time it is a story that has given us a sense of the continuity of human life with the rest of nature and with that a growing awareness of the importance of the environment and other living things we share this world with, even for our own wellbeing. This clearly has implications for the type of society we will want to live in in the future, although our understanding of what this should be is still…, well, evolving.
References
Cobb, M. and Comfort, N. (25 April 2023), What Rosalind Franklin truly contributed to the discovery of DNA’s structure. Nature (Online): https://www.nature.com/articles/d41586-023-01313-5
Depew, D. J. and Weber, B. H. (1995), Darwinism Evolving: Systems Dynamics and the Genealogy of Natural Selection. Cambridge, MA: MIT Press.
Gould, S.J. and Eldredge, N. (1977), Punctuated Equilibria: The Tempo and Mode of Evolution Reconsidered. Paleobiology, Vol. 3, No. 2 (Spring, 1977), pp. 115-151 (37 pages)
Havstad, J.C. (2011), Problems for Natural Selection as a Mechanism. Philosophy of Science, Volume 78, Issue 3 (July 2011), pp. 512 – 523.
Mayr, E. (1985), The Growth of Biological Thought: Diversity, Evolution, and Inheritance. Harvard, MA: Belknap Press, p.757.
Narby, J. (1999), The Cosmic Serpent: DNA and the Origins of Knowledge. London: Wiedenfeld & Nicholson.
Wilson, D. (2009), Natural selection and complex systems: A complex interaction. In C. Hemelrijk (Ed.), Self-Organisation and Evolution of Biological and Social Systems (pp. 151-165). Cambridge: Cambridge University Press.
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