Tuesday, June 17, 2014

Book Review: The Gaia Hypothesis, science on a pagan planet

Michael Ruse: The Gaia Hypothesis, science on a pagan planet. University of Chicago Press, 2013. 224 pages, references, index, figures

Gaia Hypothesis: formulated by British inventor / physical chemist James Lovelock and American biologist Lynn Margulis, circa 1970. In essence, this "hypothesis" holds that the living species of earth have "co-evolved" so as to regulate essential properties of their physical environment (temperature, oxygen level, acidity, salinity..) for the mutual benefit of all. (Alternative definitions are possible.) I placed the term hypothesis in quotes because some scientists refuse to grant it such high status.

       The Gaia hypothesis owes its genesis to the American space program. Lovelock was contracted by NASA, the American Space Agency, to devise a way to detect life on distant planets. Lovelock - showing his native genius - came up with an elegant and efficient method: search for spectral lines indicating the presence of life supporting molecules in the planet's atmosphere. Spectral lines are monochromatic emissions / absorptions of light (or similar radiations) by atoms or molecules. 

An example: the biogenic oxygen of earth's atmosphere, produced by plant photosynthesis, is converted to small quantities of ozone in the upper layers of the earth's atmosphere. Ozone strongly absorbs some ultraviolet rays and the resulting absorption lines could be used as a "biosignature" indicating the potential existence of life on an earthlike planet.


       Prof Ruse is a philosopher of science at Florida State University. His goal in writing this book is to situate the Gaia Hypothesis within the contemporary cultural context and to analyze it from the perspective of philosophy and accepted scientific theory. (A somewhat circular proposition, one might argue, since philosophy and scientific analysis are also products of the ambient culture!) For me, the work was worth the effort, informing and stimulating, raising interesting questions and perspectives about the role of science in society today, some of them quite subtle and unexpectedly deep ("philosophical").

      Gaia Hypothesis reveals the mutual interactions - conflictual or symbiotic - between 1- the various "institutions" that comprise society, 2- science (itself one of these institutions), and 3- the work of the scientist. A flagrant example of such interactions are Darwin's attitudes towards catastrophic - rapid - change in the natural world. The industrial revolution created an increased demand for minerals and coal.  The increased intensity of mining operations combined with the emergence of modern scientific investigation of the natural world revealed what we now call the "fossil record", the mineralized remains or impressions of ancient life forms in soil and rock strata. From the beginning it was evident that this "record" contained many gaps, was fragmentary. Religionists tended to interpret these gaps as evidence for the Great Deluge of the Old Testament when an angry God punished sinful mankind with near universal destruction. The Deluge, it was held, also caused many animal and plant species to go extinct: dinosaurs were too large to fit on Noah's ark and so were left behind (!!) 

      As the fossil record became more complete, several gaps, corresponding to radical shifts in biota remained. Some thinkers argued for multiple deluge-like chastisements on the part of God. Others saw multiple creations / destructions of the the living world, either by Divine Providence or Natural Causation.

      As an avowed - and militant -atheist Darwin rejected such "episodic" or "discontinuous" interpretations of World History. And, be it noted, he also rejected the evidence of the fossil record itself. He, along with other scientists (geologists, naturalists,..), proposed an alternative hypothesis: Gradualism (other terms have been employed) which held that natural processes in the past are 1- essentially identical to those of today, 2- act steadily over time (at least on large geographic and time scales ) and 3- the gaps in the fossil record are simply due to physical discontinuities in geological processes. Thus a layer of dino bones under a layer of modern looking mammal bones need not imply a biological discontinuity. Instead, changes in hydrology, land elevation, sea level, etc might have resulted in erosion of intervening layers of fossils before a new phase of fossil deposition began. If we had a more complete record, Darwin argued, we would see dinosaur species slowly dying out and being replace by primitive mammals.

         Today, with increased knowledge of the chronology of geological events and a more complete fossil record, we have come to the conclusion that, effectively, Darwin was wrong and the religionists right (though for the wrong reasons!). Evolution is, in fact, marked by relative discontinuities - mass extinctions - which have profoundly modified the course of terrestrial biological evolution, a position sometimes referred to as "Neo-catastrophism".



        The lesson I drew from reading Prof Ruse's book is that science is, in part (and, to me, only in part), a "social construction". The scientist and the hypotheses which emanate from his brain do not emerge fully formed from the brain of Zeus! Rather, the scientist and his hypotheses are immersed in and emerge from a social, cultural, political matrix which, itself, has a history, a trajectory, a momentum, a "becoming" (French: un devenir). Science, and scientists, interact with, modify, and are modified by the institutions and the times they inhabit. There are quite a few examples in the book of such interactions, some a bit amusing, all informing.

        Thus, Rachel Carson, the pioneering ecological activist and author of Silent Spring (1962,) was not just an idealist but a consummate strategist to boot. One of her major informants of on-the-ground ecosystemic damage caused by pesticides was a biodynamic gardener, writer and speaker. Biodynamics is a form of organic farming developed by the Austrian medium-mystic Rudolf Steiner (1861 - 1925). Steiner can be seen as a forerunner of contemporary New Age movements and sects. He founded a philosophical, mystical, ethical school - Anthroposophy - and the Waldorf School system of alternative education based on play and creative self-expression within a social context.

          Rachel Carson, wisely, backed away from any overt association with her biodynamic collaborators. She realized that association with such marginals could be used against her by the large chemical companies who manufactured the pesticides she was denouncing.

          Science and society mutually interact. Point taken.

         James Lovelock is a British physical chemist and independent researcher / inventor who is proud of his lack of dependence upon direct institutional or government funding (of course, some of his clients, like the National Aeronautical and Space Administration (USA), are government funded, meaning that Lovelock does receive some indirect institutional funding).

        Lovelock is a gifted scientific instrument inventor with numerous patents to his name. He has occasionally invented instruments that the scientific community said were "impossible".


        For me, the most fascinating parts of Prof Ruse's book dealt with the philosophical aspects of the "Gaia debate".

        There are probably at least two levels to this debate. On the popular level, a large section of the public - vaguely anxious by the disquieting roles science and technology are playing  - uncritically embraces several popular versions (?or debasements?) of the hypothesis. Perhaps the hypothesis affords us a way of tapping into a "holistic" vision of the world, a type of thinking many people intuitively recognize is lacking in our modern materialistic, reductionist - "scientific" - way of thinking and approaching problems. Many things have been read into the Gaia Hypothesis that Lovelock and Margulis, especially the former, never proposed: Gaia is a conscious being, "She" is the "soul of the World" (the Anima Mundi of ancient philosophy), Gaia consciously directs evolution. She may even be placated or induced through magical rites into satisfying human desires (the analogy with traditional forms of payer for divine intervention is only too evident!) Any or all of these positions, beliefs or practices may, of course, be valid (from various perspectives) but, in reality, they form part of the popular reaction to the hypothesis and do not necessary represent what Lovelock was trying to say. On the scientific level of analysis, Lovelock saw Gaia as the biochemically integrated  and goal directed behavior of the totality of living organisms on earth. The goal direction - teleology - proved to be an extremely controversial point of the hypothesis for a significant segment of the scientific community. Darwinists, in particular, because of their early battles with Christian creationists, were always sceptical of explanations involving teleology (purpose).

         Lovelock's lack of training in biological science began to show. In nature, "form follows function": wings are adapted to flying. But wings, Darwinists insist, were not "designed" by some Great Designer in the Sky. Rather, adaptations - like flight - that increased the chances of passing on one's genes were "selected" by the "struggle for survival". Thus what functions well - without being consciously designed - survived and is passed on, even becoming more perfect over time (Darwin). But, in the case of Gaia, where does the selection that would give rise to her integrated, self-regulating properties come from? Gaia is obviously not an individual organism to be eliminated in some competitive race to survive long enough to pass genes to the next generation. Since selection only operates on the individual in competition, "Gaia" could not have evolved self regulating properties.

         In some fundamental ways, Ruse argues, Lovelock failed to really grasp the point the Darwinists were trying to make. I suspect this is the case. Years ago, my environmental interests led me to study the Gaia Hypothesis. In reading Lovelock, I was at times a bit shocked with what blithe naivete he introduced ad hoc teleological explanations to explain Gaia's workings.

          For example, he explained the production of iodine containing gases by sea kelp as an (essentially) altruistic mechanism to transport iodine inland for the benefit of land vertebrates. These organisms have thyroid glands which require iodine to function. Whoa! Wait a minute! I thought. What is the advantage the sea kelp get from pumping gaseous iodine shoreward? There appears little or no benefit to the kelp. Lovelock simply didn't know enough about the rules of the biology game, did not understand the ideology of the biological community.

         A more "ideologically acceptable" explanation of the kelps' iodine transport looks at the benefits to the kelp of extracting iodine from seawater. The kelp employ the iodine they extract to reduce the salinity of the interior of their cells. Too much salt is harmful. A byproduct - unintended - of the kelps' "self-serving" iodine metabolism is the release of iodine to the atmosphere. Prevailing winds then carry it inland and vertebrate life, at some point in its evolution, began to exploit the ambient iodine as a metabolic booster (the hormone thyroxine). The latter point is important: land vertebrates began to exploit iodine because it was ALREADY present in the environment and had appropriate chemical properties. The kelp do NOT send iodine for our benefit! Such bad science did not help Gaia's reception among scientists who were more critical, on the whole, than the public.

         It is at this point that the whole debate begins to take on a philosophical / ideological flavor and touch on some really fundamental questions about the way the universe works. We touch here on the question of individual versus group evolutionary selection. Or the perennial war in Western science of "reductionism" versus "holism" (now appearing in the guise of contemporary issues and interests). 

         Lynn Margulis (1938 - 2011), who joined Lovelock in popularizing the Gaia Hypothesis, was, however a trained - if sometimes controversial - biologist and a self-avowed holistic thinker. She was probably better equipped intellectually to recognize the ground she was fighting on, the nature of the battle and the arms to employ. Ruse notes that her collaboration with Lovelock in popularizing the Gaia Hypothesis was fairly short lived. Ruse suggests this may have been due to Lovelock's (essentially) ideological commitment to a deterministic - reductionist worldview inherited from his training in the physical (as opposed to the biological) sciences.

         Scientific fundamentalism? "Fundamentalist" Darwinists insist that natural selection only selects fitter individuals. This is the classical default position, honed by decades of intellectual warfare with religionists (creationists, theists) and "holists" seeking some "vital" essence in life which distinguishes it from non-life. Holism, in addition, has, especially in popular manifestations, tended to attract some pretty hairy characters, further eroding its credibility among "serious" scientists.

        Since the 1970s, Evolutionary Psychologist (AKA Sociobiologist), E O Wilson has argued that more global traits of organisms, those involving social interactions between individuals, can also be selected for. Such selection could operate on a gene regulating a neurotransmitter associated with an increased tendency for social cooperation between individuals of a species. If increased cooperation had survival value, claims Wilson, the gene in question would, of course, be selected for. Groups in which the gene was more prevalent would out compete groups with lower levels of the neurotransmitter. They would produce more offspring. Thus the mutant gene would rise in frequency over time. But the competing entities here would no longer be individual but groups of individuals of a given species in competition with other groups of the same species. The group, not the individual, is the site of selection in this hypothesis. Some Darwinists, however, seem intellectually incapable of accepting - or even understanding - such an idea. Science too has its fundamentalists..



       Basically, the debate between individual versus group selection may be seen as a case of the old Holism versus Reductionism Wars. Reductionists live in a Lego universe:

           "Wholes" - organisms, living cells, ecosystems, molecules, societies.. (anything which has an identifiable boundary) - can, for the reductionist, be broken down into "elemental" functional subunits: atoms, chemical elements.. whose behavior can be described, usually, with simple mathematical equations. Theoretically, if one has a complete set of elemental subunits, properly described, one should be able to completely describe any complex entity composed of the subunits as well as its behavior(s).

                               A cityscape represented in Lego blocks (as "atomic units")

            Much of the power of modern technology derives from applying reductionist analyses to the physical world. We need only think of the way modern gadgets are constructed to the see the "lego world" mentality at work. (Lego itself is a cultural artifact produced by a reductionist industrial mind set - it merely reflects back the worldview it emerged from..)

           Today, however, our proliferating, interlocking, mutually reinforcing crises - demographic, environmental, climatological, technological, economic, spiritual,.. - are demonstrating the limits of such reductionist approaches to complex, self-organizing systems like our world. Such "wholes" are now seen to be demonstrably "more than the sum of their parts". Otherwise we would not be in the trouble we now are! Complex self-organizing wholes though which energy and matter flow, we now are beginning to understand, are systems that generate novelty and surprises (technically speaking, these are dissipative systems - footnote 1). Life itself is the major novel "emergent" we observe on earth. Such systems, while indeed composed of simpler elements, causally linked by simple equations, need to be observed "from the top down" if we are to grasp their most interesting - "emergent" - behaviors. We must adopt a holistic approach to grasp their full complexity and richness of response.

          For me, the most interesting point is not whether such behavior actually exists in Gaia but the degree of ideological commitment  shown by opposing sides and how this commitment expresses itself. Such commitment - sometimes bordering on fanaticism - often results in people "talking over each other's head".

        In truth, it is still too early to say if Gaia has legs and will last. At the very least it is a useful metaphor, especially at the popular level, to get people to consider the impacts of our economic behavior on the world we live in and how these impacts affect our own health and welfare. Gaia says: what goes round, comes round. But as a scientific theory, it is still early days and the jury's still out..

        I liked this book. Give it maybe 8 on 10. I apologize for the text in white background above. The internet gremlins are responsible, not me - I tried to remove it several times. Any suggestions, from the techies..?


1- dissipative system: examples - organism, living cell, beehive.. but also some non-living systems like hurricanes, tornadoes, the earth's climate "machinery", crystals and viruses. Typically such a system has an active, more or less well-defined, boundary which separates it functionally from its (usually simpler) environment. Generally, "small" amounts of matter may (usually are) exchanged with the environment across the boundary: food goes in, waste goes out (in the case of organisms). Most importantly, energy (including information) crosses the boundary and a significant amount of energy is stored within the boundary (for example as fat tissue, a source of energy for emergencies). The "system" - the stuff inside the boundary - uses the energy flow across the boundary to do self-organizational work: the metabolism of the cell repairs cellular damage. When growing, the cell increases its mass, using matter fror the environment. Energy absorbed (from food) is used to organize that matter into living tissues. Waste heat - degraded (high entropy) energy - is evacuated to the environment. The system is said to organize itself - self-organize - at the entropic "expense" of its environment (2nd law of thermodynamics). To organize itself the system degrades high quality (low entropy) energy - such as sunlight - into degraded (high entropy) waste heat. The waste heat released to the environment has a reduced capacity to do further useful work (thus is said to be "degraded energy").


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