It is sometimes said that the standpoint of dialectics is identical with that of evolution. There can be no doubt that these two methods have points of contact. Nevertheless, between them there is a profound and important difference which, it must be admitted, is far from favouring the teaching of evolution. Modern evolutionists introduce a considerable admixture of conservatism into their teaching. They want to prove that there are no leaps either in nature or in history. Dialectics, on the other hand, knows full well that in nature and also in human thought and history leaps are inevitable. But it does not overlook the undeniable fact that the same uninterrupted process is at work in all phases of change. It only endeavours to make clear to itself the series of conditions under which gradual change must necessarily lead to a leap.

– Plekhanov, Selected Philosophical Works

Darwin regarded the pace of evolution as a gradual process of orderly steps. It proceeded at a constant rate. He adhered to Linnaeus’ motto: “Nature does not make leaps.” This conception was reflected elsewhere in the scientific world, most notably with Darwin’s disciple, Charles Lyell, the apostle of gradualism in the field of geology. Darwin was so committed to gradualism, that he built his whole theory on it. “The geological record is extremely imperfect,” stated Darwin, “and this fact will to a large extent explain why we do not find interminable varieties, connecting together all the extinct and existing forms of life by the finest graduated steps. He who rejects these views on the nature of the geological record will rightly reject my whole theory.” This Darwinian gradualism was rooted in the philosophical views of Victorian society. From this “evolution” all the leaps, abrupt changes and revolutionary transformations are eliminated. This anti-dialectical outlook has held sway over the sciences to this present day. “A deeply rooted bias of Western thought predisposes us to look for continuity and gradual change,” says Gould.

However, these views have given rise to a heated controversy. The present fossil record is full of gaps. It reveals long-term trends, but they are also very jerky. Darwin believed that these jerks were due to the gaps in the record. Once the missing pieces were discovered, it would reveal a gradual smooth evolution of the natural world. Or would it? Against the gradualist approach, palaeontologists Niles Eldredge and Stephen Jay Gould have put forward a theory of evolution called punctuated equilibria, suggesting that the fossil record is not as incomplete as had been thought. The gaps could reflect what really occurred. Gould argues that evolution proceeds with leaps and jumps, punctuated with long periods of steady, gradual development.

The history of life is not a continuum of development, but a record punctuated by brief, sometimes geologically instantaneous, episodes of mass extinction and subsequent diversification. Rather than a gradual transition, modern multicellular animals make their first uncontested appearance in the fossil record some 570 million years ago – and with a bang, not a protracted crescendo. This ‘Cambrian explosion’ marks the advent (at least into direct evidence) of virtually all major groups of modern animals – and all within the minuscule span, geologically speaking, of a few million years.[67]

Gould also points to the feature that the boundaries of geological time coincide with turning points in the evolution of life. This conception of evolution comes very close to the Marxist view. Evolution is not some smooth, gradual movement from lower to higher. Evolution takes place through accumulated changes which burst through in a qualitative change, through revolutions and transformations. Already at the end of the 19th century, the Marxist George Plekhanov polemicised against the gradual conception of evolution:

German idealist philosophy, decisively revolted against such a misshapen conception of evolution. Hegel bitingly ridiculed it, and demonstrated irrefutably that both in nature and in human society leaps constituted just as essential a stage of evolution as gradual quantitative changes. ‘Changes in being,’ he says, ‘consists not only in the fact that one quantity passes into another quantity, but also that quality passes into quantity and vice versa. Each transition of the latter kind represents an interruption in gradualness, and gives the phenomenon a new aspect, qualitatively distinct from the previous one’.[68]

“Evolution” and “revolution” are two sides of the same process. In rejecting gradualism, Gould and Eldredge have sought an alternative explanation of evolution, and have been influenced by dialectical materialism. Gould’s paper on “Punctuated Equilibria” draws parallels with the materialist conception of history. Natural selection theory is a good explanation of how species get better at doing what they do, but provides an unsatisfactory explanation for the formation of new species. The fossil record shows six major mass extinctions took place at the beginning and end of the Cambrian period (600 million and 500 million years ago respectively), and the ends of the Devonian (345 million years ago), the Permian (225 million), the Triassic (180 million) and the Cretaceous (63 million). A qualitatively new approach is needed to explain this phenomenon.

The evolution of a new species is marked by the evolution of a genetic make-up that allows members of the new species to breed with each other, but not with members of other species. New species arise from a branching off from ancestral stocks. That is, as Darwin explained, one species descended from another species. The tree of life shows that more than one species can be traced back to one ancestral stock. Humans and chimpanzees are different species, but had one common extinct ancestor. Change from one species into another takes place rapidly between two stable species. This transformation does not take place in one generation or two, but over possibly hundreds of thousands of years. As Gould comments:

This may seem like a long time in the framework of our lives, but it is a geological instant…If species arise in hundreds or thousands of years and then persist, largely unchanged, for several million, the period of their origin is a tiny fraction of one per cent of their total duration.

The key to this change lies in geographical separation, where a small population has become separated from the main population at its periphery. This form of speciation, called allopatric, allows a rapid evolution to take place. As soon as an ancestral species is separated, the inter-breeding stops. Any genetic changes build up separately. However, in the smaller population, genetic variations can spread very quickly in comparison to the ancestral group. This can be brought about by natural selection responding to changing climatic and geographical factors. As the two populations diverge, they eventually reach a point where two species are formed. Quantitative changes have given rise to a qualitative transformation. If they ever meet in the future, then so genetically divergent are they, that they are unable to breed successfully; either their offspring will be sickly or sterile. Eventually, similar species with the same way of life would tend to compete, leading eventually to the extinction of the least successful.

As Engels commented:

“The organic process of development, both of the individual and of species, by differentiation, is the most striking test of rational dialectics.” Again, “The further physiology develops, the more important for it becomes these incessant, infinitely small changes, and hence the more important for it also the consideration of differences within identity, and the old abstract standpoint of formal identity, that an organic being is to be treated as something simply identical with itself, as something constant, becomes out of date.” Engels then concludes: “If there the individuals which become adapted survive and develop into a new species by continually increasing adaption, while the other more stable individuals die away and finally die out, and with them the imperfect intermediate stages, then this can and does proceed without any Malthusianism, and if the latter should occur at all it makes no change to the process, at most it can accelerate it.”[69]

Gould correctly says that the theory of punctuated equilibria is not in contradiction to the main tenet of Darwinism, natural selection, but, on the contrary, enriches and strengthens Darwinism. Richard Dawkins in his book The Blind Watchmaker attempts to downgrade Gould and Eldredge’s recognition of dialectical change in nature. He sees little difference between “real” Darwinian gradualism and “punctuated equilibria”. He states: “The theory of punctuated equilibrium is a gradualist theory, albeit it emphasises long periods of stasis intervening between relatively short bursts of gradualistic evolution. Gould has misled himself by his own rhetorical emphasis…” Dawkins then concludes, “in reality, all are ‘gradualists’.”

Dawkins criticises the punctuationists for attacking and misrepresenting Darwin. He says we need to see Darwin’s gradualism in its context – as an attack on creationism. “Punctuationists, then, are really just as gradualist as Darwin or any other Darwinian; they just insert long periods of stasis between spurts of gradual evolution.” But this is not a secondary difference, it is the essence of the matter. To criticise the weakness of Darwinism is not to undermine its unique contribution, but to synthesise it with an understanding of real change. Only then can Darwin’s historic contribution be fully rounded out as an explanation of natural evolution. As Gould correctly says, “The modern theory of evolution does not require gradual change. In fact, the operation of Darwinian processes should yield what we see in the fossil record. It is gradualism that we must reject, not Darwinism.”[70]

  1. Gould, S. Wonderful Life, pp. 54 and 24.

  2. Plekhanov, G. The Development of the Monist View of History, pp. 96-7.

  3. Engels, F. Dialectics of Nature, pp. 154, 162 and 235, 1946 edition.

  4. Gould, S. The Panda’s Thumb, p. 151.