III. An Organic Habitable Zone UniVerse
2. Earth Alive: A Bio-Eco-Ovo Sphere Sustains Her/His Self
Earth’s biosphere is now known to have regulated itself for some billion years in a homeostatic fashion so as to sustain conducive atmospheric and geochemical conditions for life’s survival and evolution. Since the 1970's, the British geochemist James Lovelock, with Lynn Margulis and colleagues, have provided theoretical and experimental support for living systems as a planetary phenomenon. Lovelock's country neighbor, the author William Golding, suggested the name of the earth goddess Gaia. The concept has received intense scrutiny, often rejection, over past decades but has become understood and accepted as an innovative, useful model.
Meyers, Stephen and Alberto Malinverno. Proterozoic Milankovitch Cycles and the History of the Solar System. Proceedings of the National Academy of Sciences. 115/6363, 2018. University of Wisconsin and Columbia University geoscientists expand Earth’s environs to include a dynamic spacescape and temporal depth to its earliest origin. See also Exo-Milankovitch Cycles II: Climates of G-dwarf Planets at arXiv:1805.00283.
Periodic variations in Earth’s orbit and rotation axis occur over tens of thousands of years, producing rhythmic climate changes known as Milankovitch cycles. The geologic record of these climate cycles is a powerful tool for reconstructing geologic time, for understanding ancient climate change, and for evaluating the history of our solar system, but their reliability dramatically decreases beyond 50 Ma. Here, we extend the analysis of Milankovitch cycles into the deepest stretches of Earth history, billions of years ago, while also reconstructing the history of solar system characteristics, including the distance between the Earth and Moon. Our results improve the temporal resolution of ancient Earth processes and enhance our knowledge of the solar system in deep time. (Significance)
Alvarez, Walter. A Most Improbable Journey: A Big History of Our Planet and Ourselves. New York: Norton, 2016. In a novel volume, the eminent UC Berkeley geologist joins this popular union of human temporal appearance with a cosmic evolutionary rooting. We log in at the same time as David Christian’s Big History and David Grinspoon’s The Earth in Human Hands. But the three otherwise fine works reflect a tacit mindset, or lack thereof, that this grand cosmos to culture vista yet results from random contingency or chance, a lottery without occasion or destiny, not to occur elsewhere or again.
One in a million doesn’t even come close. Not when we’re talking about the odds that you would happen to be alive today, on this particular planet, hurtling through space. Almost fourteen billion years of cosmic history, over four billion years of Earth history, a couple million years of human history, the rise and fall of nations, the unbroken string of generations necessary to lead to you―it’s staggering to consider. Yet behind everything in our world, from the phone in your pocket to even the force of gravity itself, lies a similarly grand procession of highly improbable events. This panoramic viewpoint has captured the imagination of historians and scientists alike, and together they’ve created a new field―Big History―that integrates traditional historical scholarship with scientific insights to study the full sweep of our universe and its past. Famed geologist Walter Alvarez―best known for the impact theory explaining dinosaur extinction―has championed a science-first approach to Big History, and A Most Improbable Journey is one of the first Big History books to be written by a scientist rather than a historian. (Publisher)
Arenes, Alexandra, et al. Giving Depth to the Surface: An Exercise in the Gaia-Graphy of Critical Zones. Anthropocene Review. Online June, 2018. We note this entry by a landscape planner A. Arenes, the sociologist of science Bruno Latour and geochemist Jerome Gaillardet, as a visual exercise to take in the whole bio-regulated Earth as some manner of solar heated, life bearing, people evolving, preciously fertile abode.
Foregrounding the importance of soil and more generally the surface of the Earth – what is now often called the critical zone (CZ) – remains very difficult as long as the usual planetary view, familiar since the scientific revolution, is maintained. In this joint effort coauthored by a landscape architect, a historian of science and a geochemist, we propose what is called in history of drawing an anamorphosis, a change in perspective that allows us to shift from sites located in the geographic grid, to a representation of events located in what we call a Gaia-graphic view. We claim that such a view is much better suited to situate the new actors of the Anthropocene because it brings pride of place to the CZ. (Abstract edits)
Arney, Giada, et al. The Pale Orange Dot: The Spectrum and Habitability of Hazy Archean Earth. Astrobiology. 16/11, 2016. In the thrall of our global collaboration, an astroscientist team from the USA, UK, and France cast back some 2.6 billion years to reconstruct ancient climates, photochemistry, and especially fractal atmospheric hazes and clouds. Whom then is this personsphere progeny arising out of the mists to be able to learn this? As if a late blossom or birth, what does it say about what manner of organic object an Earth might be?
Benner, Steven, et al. Planetary Biology. Science. 296/864, 2002. As “a civilization-wide enterprise,” the global expanse of life and its human phase is reconstructed akin to a developing, cognizant organism.
Consequently, one can imagine a comprehensive model of life on Earth combining paleontology, geology, structural biology, systems biology, and genomics, that captures history and function from molecule to the planet. (867)
Bunyard, Peter, ed. Gaia in Action: Science of the Living Earth. Edinburgh: Floris Books, 1996. Scientific and philosophical papers explore this holistic, ecological hypothesis. The authors look toward the Russian geoscientist Vladimir Vernadsky as its original founder earlier in the 20th century whose theories of the inherent emergence of living matter informs the volume.
Crist, Eileen and H. Bruce Rinker, eds. Gaia in Turmoil: Climate Change, Biodepletion, and Earth Ethics in an Age of Crisis. Cambridge: MIT Press, 2010. This hypothesis is not in peril, rather it is the biosphere due to an unchecked onslaught from a consumptive civilization. The usual proponents from James Lovelock himself, still fiesty at ninety, Lynn Margulis, Tyler Volk, Stephan Harding, Timothy Lenton, Connie Barlow, and an array of ecologists and philosophers who weigh in with the latest impressions. The editors introduction is “One Grand Organic Whole.” A salient contribution is “Principles of Gaia Governance” by University of Washington political scientist Karen Litfin.
Dauphas, Nicolas. The Isotropic Nature of the Earth’s Accreting Material through Time. Nature. 541/521, 2017. The University of Chicago geophysicist reports new findings about how our home bioplanet formed by gradual additions of moon, and meteorite size masses, which were similar in chemical composition. This work, along with a companion article Ruthenium Isotopic Evidence for an Inner Solar System Origin of the Late Veneer (mantle) in the same issue, merited notice as Earth’s Building Blocks (541/468).
Dobretsov, Nikolay, et al, eds. Biosphere Origin and Evolution. New York: Springer, 2008. Guided by the foundational influence of Vladimir Vernadsky, along with their integral proclivity, Russian geoscience tends to the whole biosphere as the proper subject of study. This latest volume from various Institutes of Geophysics, Paleontology, Cytology, Microbiology, and so on, views “living matter” as quite engaged in the achievement of a global “homeostatic” system. The sciences of self-organizing complexity are somewhat mechanically employed to explore life’s hierarchy from a proposed “astrocatalysis” all the way to scientific civilization.
Doolittle, W. Ford. Making Evolutionary Sense of Gaia. Trends in Ecology & Evolution. Online May, 2019. The veteran Dalhousie University biologist has long disavowed this hypothesis of a steady self-regulating biosphere. It just does not square with or be explained by standard Darwinian selection. However as this vital theory has steadily grown by way of robust study and application, the author offers a novel rationale, much to his credit, as to how this presence is indeed possible.
The Gaia hypothesis in a strong and frequently criticized form assumes that global homeostatic mechanisms have evolved by natural selection favoring the maintenance of conditions suitable for life. Traditional neoDarwinists hold this to be impossible in theory. But the hypothesis does make sense if one treats the clade that comprises the biological component of Gaia as an individual and allows differential persistence – as well as differential reproduction – to be an outcome of evolution by natural selection. Recent developments in theoretical and experimental evolutionary biology may justify both maneuvers. (Abstract)
Downing, Keith. Exploring Gaia Theory. Mark Bedau, et al, eds. Artificial Life VII. Cambridge: MIT Press, 2001. By means of evolutionary computation and simulation models for a natural selection on a global scale.
Dyke, James and Iain Weaver. The Emergence of Environmental Homeostasis in Complex Ecosystems. PLoS Computational Biology. 9/5, 2013. As readers know, James Lovelock’s 1970s Gaia hypothesis of Earth’s viable biosphere as a self-regulated and sustained system due to life’s geological, ecological and atmospheric effects has been under much study since, often attack, but leading to a general affirmation and practical acceptance. Here University of Southampton, Computational Modelling Group, researchers (see web bios below) further quantify and concur that, dare one say, the living planet seems to be actually be taking physiological and anatomical health care of itself.
The Earth, with its core-driven magnetic field, convective mantle, mobile lid tectonics, oceans of liquid water, dynamic climate and abundant life is arguably the most complex system in the known universe. This system has exhibited stability in the sense of, bar a number of notable exceptions, surface temperature remaining within the bounds required for liquid water and so a significant biosphere. Explanations for this range from anthropic principles in which the Earth was essentially lucky, to homeostatic Gaia in which the abiotic and biotic components of the Earth system self-organise into homeostatic states that are robust to a wide range of external perturbations. Here we present results from a conceptual model that demonstrates the emergence of homeostasis as a consequence of the feedback loop operating between life and its environment. Formulating the model in terms of Gaussian processes allows the development of novel computational methods in order to provide solutions. We find that the stability of this system will typically increase then remain constant with an increase in biological diversity and that the number of attractors within the phase space exponentially increases with the number of environmental variables while the probability of the system being in an attractor that lies within prescribed boundaries decreases approximately linearly. We argue that the cybernetic concept of rein control provides insights into how this model system, and potentially any system that is comprised of biological to environmental feedback loops, self-organises into homeostatic states. (Abstract)