Gaia and Evolution (preface)

If we accept the Gaia Thesis, in which the Earth is seen to be a planetary system with certain self-regulating features that are controlled by the combined activities of the biota, such as surface temperature, climate, oxidation state and acidity, then such acceptance must profoundly affect our view of Evolution. Life, as Jim Lovelock has pointed out, is essentially social, and it is the colligative properties of such associations of life that characterise planetary self-regulation. And because of the profound influence that life has had on its surroundings it becomes inconceivable to divorce life from the environment itself.

Once we realise the impact of the activities of living organisms on geological structures, on the atmospheric gases in terms of their oxidation state, their albedo and their greenhouse effect, on the sea and its saltiness, on the formation of rain through evapo-transpiration and the generation of cloud-condensation nuclei, perhaps even on tectonic plate movement, then we see indeed that life is not just a thin, fragile skin on the surface of a dead, inanimate planet—having adapted ingeniously enough to the conditions that it finds—but that life has transformed the planet into a gigantic self-regulating system involving massive energy transfers from the Sun to the Earth’s surface and back again to Space. Meanwhile, just enough energy is retained so that the Earth’s temperature stays within life-enhancing limits. In fact, the environment and life form a closely-knit partnership in which both evolve together. As Lovelock points out in The Ages of Gaia, “Life and its environment are so closely coupled that evolution concerns Gaia, not the organisms or the environment taken separately”. One might say that Gaia and evolution are two sides of the same coin.

The Gaia thesis is anathema to neo-Darwinists, such as the Oxford biologist, Richard Dawkins, who see evolutionary change resulting from the natural selection of organisms that through random mutations at the genetic level are somehow better adapted in the struggle for existence and can leave behind more successful progeny. Theirs is a reductionist thesis par excellence since it holds that random changes at the level of individual genes—hence the notion of selfish genes—will by chance match better with something out there—the environment—than will some putative competitor. In his refutation of the Gaia thesis, Dawkins came up with the proposition that the Earth, as a Gaian system, would have had to have been the one success story out of a succession of failures, since how could a lowly organism or even more so its genes have any idea of what was required on a planetary scale?

In fact, Lovelock and his colleagues, particularly those at the Plymouth Marine Biological Laboratories, have answered such criticisms through the Daisyworld model. Admittedly such a model is simplistic compared to Gaia, but it demonstrates how cybernetic systems can evolve once the environment is tied in with evolution in an inseparable process.

Today, there is certainly more evidence for Gaia as an evolutionary process than there is for neo-Darwinism. Evolution thus both generates niches, both physical and chemical, and then fills them: indeed any ecosystem exhibits a host of interactions and energy exchanges that have the net result of establishing some homeostatic status quo. For that reason Lovelock sees Gaia primarily as a geophysiological system in which opportunities for survival combine with efficient use of resources and their recycling.

As Sidney Fox and others point out, randomness plays little part in the organism’s strategy for survival. On the contrary, according to Teddy Goldsmith, the organism adapts to its environment within acceptable limits through prediction. That prediction gives the semblance of pre-adaptation.

Karl Popper, Michael Polanyi, Ludwig von Bertalanffy and others have also made it clear that Darwinism and its modern successor neo-Darwinism cannot be considered to have been scientifically proven. “In the debate on evolution,” says Bertalanffy, “there has been no more concern with proof than in the operation of a Tibetan prayer wheel.”

As many of the participants stated at the Second Symposium on Gaia held by the Wadebridge Ecological Centre, and as indicated in these proceedings, neo-Darwinism does not provide a satisfactory explanation for evolution and, however resilient it may prove to criticism, it must eventually give way to a more realistic theory. Many years ago Haldane predicted that facts would soon be discovered which would show that natural selection was not fully adequate to explain evolution. Waddington had similar thoughts. “I think”, he said at the Alpbach Symposium that “we are going to see extraordinary changes in our ideas about evolution quite soon.” Yet, although the deficiencies of neo-Darwinism have become increasingly apparent in recent years, and criticism has mounted on almost every front, it remains the official scientific explanation for evolution.

One reason for that is that its critics have not yet provided a coherent alternative to neo-Darwinism but have rather sought to modify it in different ways so that it might incorporate their various criticisms. Thus Waddington’s view of evolution is a long way from that of Huxley, Simpson, Dobzhansky and the other formulators of the Synthetic Theory (the latest version of neo-Darwinism), yet his ideas—such as that of genetic assimilation which has features in common with Lamarck’s inheritance of acquired characteristics—were formulated in such a way that they could (with a certain stretch of the imagination) be reconciled with the official doctrine.

The Neutralist School, which believed that it had shown that a large proportion of mutations were neutral vis á vis adaptation, and hence providing no particular selective advantage, also seems to have lost the strength of its own convictions. Although King and Jewkes originally titled their famous paper Non-Darwinian Evolution, they opted to remain entrenched within the Darwinian fold. So too have the advocates of punctuated equilibrium; indeed Gould, Stanley and Eldridge all appear to believe in Darwinian evolution even though Darwin himself made that celebrated statement that nature did not make leaps.

It is only in the French-speaking world, to our knowledge, where we find critics who are willing to make a clean break with neo-Darwinism and even to trace the ancestry of their ideas to Lamarck. Indeed, no one would dare admit support for Lamarckism in the English-speaking world for fear of ridicule. However, in France, Wintrebert was an avowed neo-Lamarckian; so too was Grassé, whose writings were generally ignored in the English-speaking world, except by Koestler, who quotes a number of passages from them in his superb last book Janus. Other interesting authors such as Cuenot and Vandel are distinctly neo-Lamarckian, but it could be argued that the French intellectual tradition is very different from the British, and that the French are notoriously chauvenistic about their own intellectuals.

Yet even the French neo-Lamarckians have failed to make a clean break with either Darwinism and its successor, neo-Darwinism. Undoubtedly the discovery of a mechanism that provided the small, chance mutations necessary for Darwin’s theory has held much of evolutionary science in its reductionistic grasp and for the most part prevented holistic thinking. It is there that Lovelock’s Gaia thesis opens up new ways of looking at life on Earth and the process of evolution. Moreover, it is our feeling and that of many, though not all the participants in this symposium, that a realistic and coherent theory of evolution will be developed only when a clean-break is made with neo-Darwinism.

As can be seen from Sidney Fox’s contribution to the debate, randomness is not a feature of the living world. His life-long research into the pre-biotic phase of the Earth’s history and the synthesis of proteinoids indicates a replicability of form and structure that is far from random. Given the right prevailing conditions on the Earth those 3 to 4 billion years ago, the emergence of life itself would appear to be an inevitable consequence.

A tenet of neo-Darwinism, inherited from Darwinism itself, is the survival of the fittest, hence of the individual, in a struggle for existence. Competition is therefore essential to neo-Darwinism in providing the necessary drive for selection to operate upon. According to Darwinism there can be no evolution of species without the invisible hand of natural selection, yet the long periods of stasis as revealed in the paleontological record by Gould et al, conflict fundamentally with the notion of perpetual mutations constantly pushing the individuals of a species into competition with each other and with other species.

Furthermore a number of the participants at the symposium expressed their unease with the notion of natural selection. Søren Løvtrup is sceptical both of the Darwinian notions of “fitness” and of “adaptation” since if they are measured under laboratory conditions then such a situation bears little relationship with reality. If natural selection does occur, he suggests, its power is much less than is usually supposed. Moreover, “it can only work on organisms which are already fit and partially adapted”. Mae-Wan Ho takes the criticism of natural selection further. “Natural selection”, she points out,

“depends on a conceptual separation between the environment which selects from the organisms which vary, or mutate independently of it. In reality, a host of physiological feedback interrelationships occur between organism and environment. These interrelationships have now been demonstrated to extend to the genetic material itself, which up to quite recently, has been thought to be immune from environmental influences. This means that organisms and environment are no longer neatly separable, and they must be considered as one dynamical system that undergoes a process of co-transformation with time.”

That dynamism of Gaia and its myriad parts is a theme taken up by several of the other participants. David Lambert and Richard Newcomb see the intelligibility of Gaia as having much in common with biological structuralism. They point out that the classical interpretation of evolution is to see the organism as responding passively to the action of external forces, in particular of natural selection. Therefore, if an insect becomes resistant to a pesticide the reason, according to orthodoxy, is that a mutant strain arises—by chance—that under the new circumstances is selected for, essentially by the environment. However, Lambert and his colleague point out that increasingly such resistance is being found to be the result of gene amplification in which the presence of the pesticide actually stimulates the production of its own biochemical destruction. Clearly, under such circumstances, those insects that can at the relevant stage in their life cycle use gene-amplification to their advantage will more likely survive on to reproduce. Here we undoubtedly have a phenomenon that is closer to Lamarckism than it is to Darwinism, although it incorporates elements of both hypotheses. Structuralism, in fact, is the view that understanding of the underlying principles will give an explanation of nature: equally that wholes are more than the parts and will maintain their integrity despite alterations in their constituents.

According to Brian Goodwin, the classical neo-Darwinian view of evolution is flawed because it denies the role of the organisms in evolution. “In this account,” he says, “organisms have disappeared and have been replaced by genotypes, with phenotypes as their causal effects.” Goodwin refutes the proposition that organisms can be reduced to their hereditary essences; instead he brings forward evidence that dynamic transformations taking place during morphogenesis indicate a delicate interaction at the interface of the organism with its immediate environment. The forms that result from subtle changes in chemistry—the concentration of calcium for example—can become new phenotypes, but the genes, that in neo-Darwinism are supposed to govern the form of the phenotype, remain the same. The potential for evolutionary change therefore lies to a considerable extent in morphogenesis—a subject that tends to be wholly neglected by neo-Darwinists.

As we pointed out earlier, neo-Darwinism can no longer provide an adequate explanation of evolutionary processes. At best it is only part of the story. Even Darwin’s hope that the tracing of genealogical lines would indicate centres of origin appears to have failed the test of time. Darwin had no idea of tectonic plate movement, nor indeed did Leon Croizat when he developed his panbiogeographical method of tracking the distribution of species. As Ron Brady and Giuseppe Sermonti point out, there may indeed be centres of origin but they are not evident. Instead, the empiricism of Croizat indicates that barriers to migration have certainly led to endemism and to what can be described as a close relationship between the organisms and their environment. In effect, should distant, disconnected environments be similar, then the taxons inhabiting them may show similarities, such parallel evolution being the result, suggests Sermonti, of similarities in the interaction with the environment. Again, Earth and Life can be seen to have evolved together, a confirmation of Lovelock’s Gaia thesis.

Our second symposium on the Gaia thesis, this time on Gaia and Evolution, brought together a number of different strands and with a remarkable degree of unanimity that neo-Darwinism can no longer be considered an adequate theory to explain evolution. Ironically, it is the despised Lamarck who offered some pointers to a true understanding insofar as for him living organisms were alive and hence able to take their evolution, as it were, into their own hands, in response to their immediate surroundings. Evolution must be seen as an interactive process, in which the aim is the achievement of stability within the dynamic of an ever-changing world. As Mae-Wan Ho points out, there is action in evolution and evolution in action.

 
Edward Goldsmith and Peter Bunyard

The Editors,
Gaia and Evolution: Proceedings of the Second Annual Camelford Conference on the Implications of the Gaia Thesis. Wadebridge Ecological Centre, Cornwall, UK (1989)