p. 1. Few were as far apart as the authors of this book when they first met in the 1970s. At that time, a split was appearing in the practice of science. Traditionalists were persevering with the reduction of whole systems into their constituent parts, an approach that had led to the triumphs of the decipherment of the genetic code and the new science of genomics. A different way of thinking was combining science and new social movements. Post-normal science was beginning to accept that, for complex issues such as planetary climate change and global food security, scientists needed to practise their art where facts were uncertain, values in dispute, stakes high and decisions urgent. The authors met, 45 years ago, in the Department of Zoology at The Australian National University (ANU). Chris Bryant was then a reader, with a flourishing research group in parasite biochemistry. He had remained a reductionist, focusing his attention on the subcellular mechanisms of respiration in anaerobic organisms. Val Brown, having raised a family, was a mature-age PhD student working in the then-new field of holistic thinking as applied to the human sciences. She was already a fan of Lovelock’s space-engendered view of the Earth as a self-maintaining and self-organising planetary system he named ‘Gaia’.
p. 77 Reductionism has proved to be a useful tool in science, which progresses by accretion of knowledge, so that arguments improve as more of the unknowns become known. The contrasting view to reductionism is wholism: the idea that things can have properties as a whole (emergent properties) that cannot be understood from a simple knowledge of their individual parts. Even a quick look at evolutionary history suggests that the evolutionary process is a series of emergent phenomena. Emergent properties are generally the properties of complex systems, whose complexity is the consequence of many simple, reiterated, recursive interactions. Every major evolutionary event has led to consequences that a contemporary observer, from Mars, say, could not have predicted. … The whole of the biosphere, including human social systems, is an emergent consequence of the appearance of the first cell. To do them justice, many reductionists understood this phenomenon, but chose to ignore it in the process of studying what was possible, given the state of science at the time. Up to the middle of the twentieth century, the study of biological and human systems as a ‘whole’ was difficult, unreliable and time-consuming. It created an unfortunate but pragmatic situation, where things were studied more because they could be studied, rather than because they necessarily should be.
p. 78 The advent of genomics, the study of the highly variable genetic kit owned by all organisms (see, for example, Lesk 2017), brought about another wave of scientific reductionism. Readily available ‘cookbooks’ gave the simple and detailed instructions for gene sequencing and manipulation. Graduate students were exploited as intelligent workhorses to do the menial task of gene and protein sequencing. The cynical slogans ‘one polypeptide chain, one PhD’ and later, as techniques evolved, ‘one gene, one PhD’ were current around the turn of the twentieth century! The past is indeed a foreign country and, as LP Hartley remarked, they certainly did things differently there. The sense of the connectedness of things was lost during the Enlightenment when the scientific method of destructive analysis became de rigeur. Philosophers believed that understanding came from dissection, and much understanding did come. By unweaving the network of knowledge into its component threads, the philosophers of the time were so intoxicated by their so-called objective discoveries that they lost sight of the whole.
p. 94 Even a quick look at the evolutionary history in Chapter 3 suggests that the evolutionary process is built on a series of emergent phenomena. Although emergent phenomena are commonplace, we rarely see them as such. Mistakenly, we tend to look at a whole as a static system – a reductionist view – whereas in a dynamic system, wholes are consequences of the influences of other wholes. Recurrence of a different spring in the northern and southern hemispheres is a consequence of the spin of a planet with a tilted axis in a solar system. Individual plants and animals are consequences of a fertilised ovum. Humans are the consequence of a particular pattern of DNA expressed in a social and physical context. Microscopic examination of either an unknown seed or a fertilised egg gives no clues to its final destiny. WB Yeats wrote: O chestnut tree, great rooted blossomer, Are you the leaf, the blossom or the bole? O body swayed to music, O brightening glance, How can we know the dancer from the dance? The nut that is planted becomes the ‘tree’ and the ‘tree’ is all of the things listed by Yeats in the one living form. One cannot know the ‘dancer’, nor the ‘dance’, by simply studying the choreography. ‘Dancers’ may be changed and the new ones master the same choreography with different interpretations, while the dance itself will be influenced by different settings.
p.120 , let us simply talk about cells, for the first modern cells are themselves tri- or tetra-symbionts: the interaction between two or more different cells living in close association, to the benefit of all parties. We now have a definition that includes the whole of biological creation. Individual animals and plants become symbiotic associations of cells.
p. 121
Rabbits make up for having a small, rabbit-sized intestine by eating their own faeces. This process is called coprophagy. At night rabbits produce soft, green, partially digested faeces and eat them, giving the microbes in their intestine a second go at breaking down cellulose. Important nutrients are synthesised by symbionts in the posterior, large intestine while absorption occurs in the anterior small intestine. What else can a poor rabbit do but recycle? Coprophagy also happens in rodents and it has been observed in koalas, ringtail possums, piglets, foals, dogs and nonhuman primates. Pigs regard human faeces as an excellent source of nutrition
p. 122 One truly remarkable mollusc, the sea slug Elysia, consumes algae and then makes use of their chloroplasts which go on photosynthesising for a considerable time, relocated in the skin of the sea slug and turning it into a ‘crawling green leaf’ (Mujer et al. 1996,
p. 123 The pea aphid (Acyrthosiphon pisum) has an endosymbiont bacterium called Buchnera; its primary role is to synthesise essential amino acids that the aphid cannot acquire from plant sap (Wilson et al. 2010). The tsetse fly Glossina has an endosymbiotic bacterium that is called, rather grandly, Wigglesworthia, a name that also commemorates a famous entomologist. Wigglesworthia synthesises vitamins that the tsetse fly cannot get from the blood it feeds on (Soumana et al. 2014). Without its endosymbiont, the tsetse fly could not survive – and the world would be free of the scourge of sleeping sickness
p. 124 Riftia is a marine worm that lives its strange life in close proximity to black smokers. Riftia lacks a gut and so relies for nutrition on endosymbiotic bacteria that can deal with this extreme environment (Bandi et al. 1999).
p. 143
One possible reason why the rate of change of mitochondrial DNA is greater than that in the nuclear DNA is because oxygen is dangerous stuff (Baker and Orlandi 1995). Mitochondria have to interact intimately with oxygen as it is used in energy metabolism. In making ATP (adenosine triphosphate), the ‘energy currency’ of the cell, they transfer electrons to oxygen to yield a molecule of water. In this process, highly reactive intermediate oxygen products that react with almost anything, including DNA, are produced. Damage to DNA is a constant possibility that must be avoided and there are protective molecules ready to scavenge the dangerous oxygen radicals. Even so, some of the highly reactive oxygen compounds do escape to do damage to important molecules and subcellular structures. Plants have to deal with the perils of oxygen in two systems; chloroplasts as well as mitochondria. Chloroplasts once were free-living anaerobic photosynthesisers producing oxygen as an end product of photosynthesis, and therefore have a much longer history of dealing with toxic oxygen than mitochondria. Perhaps they are better at it. They too have their antioxidants to deal with reactive oxygen. In any event, modern cells successfully crossed this barrier to symbiosis and the rest is all about you
p. 180
An Australian magpie of our acquaintance has taken the first step towards superstition. It has learned that it will probably get a morsel of food if it knocks on the window. Many birds do that, but this one hops down, waits until you open the door and then rapidly turns around on the spot. The number of turns, up to four, is a rough measure of its eagerness and appetite. It has been doing this for several years now, a behaviour that probably occurred accidentally on first acquaintance is now considered essential by the bird. It is in the position of the person who is an unfortunate performer of ritual behaviour to ensure a favourable outcome in a specific situation. Professional sportspersons often show this behaviour – footballers who insist on wearing the same socks for every game, cricketers who, when batting, perform a specific sequence of actions adjusting their armour before receiving the next delivery. It is not a great step from this to communities lighting ritual fires to ensure the Sun returns at the end of the winter. Such people – and, presumably the magpie – have an imaginary tiger by the tail. They dare not let go.
– p. 217
Studies have shown that infants in orphanages may die without emotional care before they are six years old. If they do not hear a language spoken before they are nine, they will never develop speech. If they do not use their hands (feet can replace them) as they grow, their thinking capacity will be limited. The conclusion is that humans are inherently social animals, co-dependent on opportunities for learning, and needing manual as well intellectual stimulation for growth. They learn to integrate with their social groups and learn of the rewards of cooperative behaviour.
p. 219
Genes for lactose tolerance have also spread rapidly through the British population in the last 2,000 years, presumably reflecting the historical growth of dairy farming. The introduction of milk in the diet had at least one unfortunate repercussion – the spread of tuberculosis (consumption) in Victorian England. In 1924 free milk (now tuberculin tested) in schools was introduced, and so a change of behaviours and increased health followed the first impact of the incorporation of a new component to the human diet; social evolution at its best.
p. 221
‘Survival of the fittest’ always conjures up in the popular mind the idea of competition. And that usually means, to the average farmer or gardener, competition between their crop plants and invading weed species. There is a famous cartoon from Punch of a beautiful cottage garden and a plaque on the cottage wall quoting TE Brown’s ‘A garden is a lovesome thing, God wot’. The proud gardener is leaning on his wall and remarking to an admirer ‘You shoulda seen the mess it was in when God had it to hisself!’ A well-kept cottage garden (or farm) is so far out of natural equilibrium that it is indeed a battlefield requiring constant supportive assaults from gardener or farmer.
p. 223 Recently, a paper entitled ‘Gaia 2.0’, by Lenton and Latour (2018), put forward a plausible mechanism by which Gaia herself might evolve. It is derived from observations on automata that reset, or ‘reboot’ themselves. Each time they reboot, they tend to move to a condition of greater stability. Gaia has suffered half a dozen ‘great’ extinctions – or reboots – and 20-odd ‘lesser’ extinctions, in each case leading to a new period of stability during which complexity appears to have increased. Thus, each reboot is a resetting, as long as it is not a total extinction event, and Gaia can build on what has gone before. The evolutionary tendency is thus towards stability. Based on this, the so-called Anthropocene is merely a harbinger of a new steady state.
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