The Medea Hypothesis

The Medea Hypothesis: Is Life on Earth Ultimately Self-Destructive?

PETER WARD
Copyright Date: 2009
Pages: 208
https://www.jstor.org/stable/j.ctt7ssch
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    The Medea Hypothesis
    Book Description:

    InThe Medea Hypothesis, renowned paleontologist Peter Ward proposes a revolutionary and provocative vision of life's relationship with the Earth's biosphere--one that has frightening implications for our future, yet also offers hope. Using the latest discoveries from the geological record, he argues that life might be its own worst enemy. This stands in stark contrast to James Lovelock's Gaia hypothesis--the idea that life sustains habitable conditions on Earth. In answer to Gaia, which draws on the idea of the "good mother" who nurtures life, Ward invokes Medea, the mythical mother who killed her own children. Could life by its very nature threaten its own existence?

    According to the Medea hypothesis, it does. Ward demonstrates that all but one of the mass extinctions that have struck Earth were caused by life itself. He looks at our planet's history in a new way, revealing an Earth that is witnessing an alarming decline of diversity and biomass--a decline brought on by life's own "biocidal" tendencies. And the Medea hypothesis applies not just to our planet--its dire prognosis extends to all potential life in the universe. Yet life on Earth doesn't have to be lethal. Ward shows why, but warns that our time is running out.

    Breathtaking in scope,The Medea Hypothesisis certain to arouse fierce debate and radically transform our worldview. It serves as an urgent challenge to all of us to think in new ways if we hope to save ourselves from ourselves.

    eISBN: 978-1-4008-2988-0
    Subjects: General Science, Ecology & Evolutionary Biology, Biological Sciences

Table of Contents

  1. Front Matter
    (pp. i-vi)
  2. Table of Contents
    (pp. vii-vii)
  3. [Illustration]
    (pp. viii-viii)
  4. INTRODUCTION
    (pp. ix-xxiv)

    Let us begin with a thought experiment. Envision the vast, life-filled rain forest now occupying the Amazon Basin of modern day Brazil. The wide, brown river slowly but inexorably flows eastward, carrying within its fluvial grasp unnumbered tons of mud, silt, sand, and in some places even gravel, originating either in the foothills of the rapidly eroding Andes Mountains far to the west, or from the upper reaches and banks of the river itself. Commingled with this future sedimentary rock are vast quantities of rotting plant material, ranging in size from entire trees to microscopic fragments of peat. This produce...

  5. 1 DARWINIAN LIFE
    (pp. 1-13)

    In the summer of 2007 I entered into a new experience: teaching the science of evolution to entering university students. Each of the nineteen students in my class, none older than eighteen years of age, started his or her first university class with some mixture of optimism and trepidation. Most, it turned out, wanted to be scientists. Yet in a series of short papers, most also readily admitted that while they had been well prepared in their high school classes in various mixtures of mathematics, chemistry, physics, and biology, virtually none had learned anything about what is variously labeled as...

  6. 2 WHAT IS EVOLUTIONARY “SUCCESS”?
    (pp. 14-23)

    The Pacific Northwest is moisture-shrouded much of the year; there are perhaps more different names for rain here than anywhere else in the world. Along the coastlines and islands fringing this region the rain seems a constant, with rain clouds either hanging above or coming right down to sea level, immersing life within the mist-bearing clouds themselves. Here and there, however, a few parcels of drier country exist, due to fortuitous rain shadows from the many overlooking mountains. One such place is Sucia Island, a tiny island almost straddling the U.S.–Canadian border, in the green, cold waters of the...

  7. 3 TWO HYPOTHESES ABOUT THE NATURE OF LIFE ON EARTH
    (pp. 24-54)

    In late August 2007 the Northern Hemisphere was witness to a spectacular lunar eclipse. It is rare that so large and so populated an area finds itself under the path of totality, but this one did. Near its West Coast totality (the eclipse reached totality in the very early morning hours even on the West Coast of North America), an actor and retired lawyer named Paul Taylor set fire to a four-story-tall wooden man standing serenely on a Nevadan desert at a place called Black Rock. This large effigy was scheduled to burn some days later, at the culmination of...

  8. 4 MEDEAN FEEDBACKS AND GLOBAL PROCESSES
    (pp. 55-71)

    One of the fundamental findings of Earth system science has been the discovery of numerous “feedback” systems—where a given environmental change cycles through various systems and ultimately produces further change. James Lovelock noted these early in the history of the Gaia hypothesis; one of the predictions of the various Gaia hypotheses is that biological feedbacks—in which life plays an important part in the overall system and its effects—should be dominantly “negative.” For instance, a negative biological feedback for planetary temperature would mean that rising temperatures would eventually cause the feedback system to bring about a subsequent lowering...

  9. 5 MEDEAN EVENTS IN THE HISTORY OF LIFE
    (pp. 72-90)

    This chapter presents a list of events that, combined, provide abundant evidence that effectively refutes the Gaia hypothesis. This evidence does not “prove” the Medean hypothesis; proof is difficult to nigh impossible in science. But as it will be the last one standing, the evidence presented should certainly strengthen its acceptance. First I describe a series of episodes from Earth history, each producing events that should not have occurred if the Gaia hypothesis is correct. Then I look at the long-term history of life on this planet in terms of our best estimates of biomass through time. Using this as...

  10. 6 HUMANS AS MEDEANS
    (pp. 91-97)

    One has only to be an aficionado of futuristic cinema to get a sense of how really BAD we humans are. The entire post-apocalyptic genre—the high-water mark of Blade Runner, such oldies as Soylent Green, THX 1138, the Mad Max epics, A Boy and His Dog, the Planet of the Apes old and new—points to a future that really looks not only dreadful, but dead, in most cases. From a productivity point of view, those futures look both bleak (for us humans) and positively post–mass extinction in terms of biotic biomass. Be it polluted cities (Blade Runner,...

  11. 7 BIOMASS THROUGH TIME AS A TEST
    (pp. 98-113)

    The Medea hypothesis supports the view that life decreases the prospects for more life. Therefore it can be shown that biomass will eventually decrease through time and in fact is doing so now, as we will see in this chapter. Here we will look at two different ways of judging planetary biotic “success”—through diversity and biomass through time. We will begin with biodiversity. Has the change in species through time followed patterns predicted by the Medea hypothesis, or some other pathway?

    The history of biodiversity—the assembly and measurement of diversity and boimass through time—was first considered in...

  12. 8 PREDICTED FUTURE TRENDS OF BIOMASS
    (pp. 114-125)

    As we have seen, biomass seems to be highly dependent on the amount of carbon dioxide in the atmosphere and global temperature. Many things affect the amount of carbon dioxide in the atmosphere, but since the evolution of plants, biotic weathering has become one of the most important.

    As the Sun continues to warm through time, it will cause a global warming that translates into increased weathering rates. The faster the silicate rocks in the crust weather, the more CO₂ will be removed from the atmosphere through the various chemical reactions that cause carbonate rocks to form. This continual removal...

  13. 9 SUMMATION
    (pp. 126-127)

    Let us sum up—in the shortest chapter of all. Three hypotheses have been presented. The first, the Gaia hypothesis (Optimizing), promotes the idea that life makes conditions better for itself. The second Gaia hypothesis (Self-regulating or Homeostatic) posits that life maintains conditions that, if not optimal, certainly stay within habitable bounds. Third, the Medea hypothesis suggests quite the opposite—that life, and future life, limits itself in any number of ways, and does so in no small way by causing positive feedbacks in various Earth systems necessary for life. A number of specific tests were proposed early on. They...

  14. 10 ENVIRONMENTAL IMPLICATIONS AND COURSES OF ACTION
    (pp. 128-140)

    This was the hardest chapter to write. It is far from my comfort level (science), for it called for philosophy and meditation on the future, and I therefore beg the reader to forgive my undoubted inelegance here, for philosophy and meditation are in short supply in my makeup. I will try a short summary of the main point: the implication of viewing life as Medean rather than Gaian requires a paradigm shift in our worldview.We must change from being witlessly destructive life forms to being consciously active anti-Medean life forms.

    This is a big change (one might almost call...

  15. 11 WHAT MUST BE DONE
    (pp. 141-156)

    We are in a box. Ultimately it is a lethal box, a gas chamber or fryer, depending how things work out. If we as a species are to survive, we will have to do a Houdini act.

    In this chapter I will suggest a series of engineering feats that will have to be accomplished.

    My friend and past coauthor Don Brownlee, the man who successfully guided a spacecraft far out into the solar system and retrieved bits of a comet in the now famous NASA Stardust mission (itself named for a line from Joni Mitchell’s song “Woodstock,” which pretty pins...

  16. REFERENCES
    (pp. 157-172)
  17. INDEX
    (pp. 173-180)