Life of Earth: Potrait of a Beautiful, Middle-Aged, Stressed-Out World - Hardcover

Rice Ph.D., Stanley A.

Hardcover

ISBN 10: 1616142251 ISBN 13: 9781616142254

Verlag: Prometheus Books, 2010

Inhaltsangabe

In this portrait of Planet Earth—at just about the mid point of its probable lifespan—a biologist discusses the evolution of the network of life and the crucial role played by humans in determining the future of our world.

Unlike most books on earth history, which present the story of life on our planet in terms of one chronological period after another, the author discusses Earth’s teeming diversity in terms of pivotal evolutionary developments. Among these he stresses the importance of symbiosis, sex, and altruism as key determinants of the Earth’s biodiversity.

Symbiosis—when single cells began working together—sparked the sudden appearance of complex animals. Much later symbiotic relationships led to flowering plants that depended on animals for pollination and seed dispersal.

With the advent of sexual selection, there developed an astonishing world of complex behavior and a dizzying array of life forms. In humans, sexual selection exerted a great influence on the development of our large brains.

Altruism—when species learned to work together—resulted in even greater variety and complexity. In early humans, altruism gave rise to ever-widening social circles and the spread of culture.

The author also discusses the role of photosynthesis in establishing and maintaining life on earth; the evidence for ancient natural catastrophes, which caused widespread extinctions; and the importance of religion and the recent use of scientific reasoning in the development and the future of the human species.

This eloquent, panoramic perspective is well designed to foster an appreciation for the scope of life on Earth and to encourage wise stewardship of the natural world on which our survival depends.

Über diesen Titel

Über die Autorin bzw. den Autor

Stanley A. Rice, PhD (Durant, OK) is the author of Green Planet: How Plants Keep the Earth Alive, The Encyclopedia of Evolution, The Encyclopedia of Science and Technology, and The Encyclopedia of Biodiversity. He is a professor in the Department of Biological Sciences at Southeastern Oklahoma State University.

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LIFE OF EARTH

By Stanley A. Rice

Prometheus Books

Copyright © 2011 Stanley A. Rice
All right reserved.
ISBN: 978-1-61614-225-4

Contents

List of Illustrations.....................................................9Introduction: A Pile of Rocks in the Middle of Kansas.....................11Chapter 1. Meet Mother Earth..............................................23Chapter 2. Inevitable Evolution...........................................45Chapter 3. Innovation.....................................................75Chapter 4. Symbiosis......................................................93Chapter 5. Sex............................................................109Chapter 6. Altruism.......................................................137Chapter 7. Religion.......................................................163Chapter 8. Science........................................................181Chapter 9. Faith in Photosynthesis........................................201Notes.....................................................................221Bibliography..............................................................237Index.....................................................................249

Chapter One

MEET MOTHER EARTH

This book is the biography of planet Earth, sometimes loosely called Mother Earth. "Mother Earth" is, of course, a figurative term. Earth is not a person and does not have a mind. The ancient Greeks considered Earth to be a goddess, Gaia, but modern science reveals that everything in the history and current operation of Earth has a physical, chemical, or biological explanation. There is no body or mind or goddess-spirit of Earth.

On the other hand, Earth is not just a stage upon which life acts or a storehouse from which life gets its resources. Earth is not merely the playroom and cafeteria of organisms. Twentieth-century ecologist G. Evelyn Hutchinson's phrase "evolutionary play in an ecological theater" suggests that the physical conditions of the Earth control evolution, but he also indicated that the Earth's ecosystems alter those conditions over evolutionary time. Life forms a network of interaction. Usually the most important part of an organism's environment is other organisms. Moreover, this network of life has completely transformed Earth's temperature, its atmosphere, and even its geology. The activities of organisms have filled the air with oxygen, and even much of its limestone is biological in origin. The actors in the evolutionary play are making changes in the stage as they go along. It is as if the actors were the props.

Not only has the network of life transformed the conditions of Earth, but it appears to, in some ways and imperfectly, regulate those conditions, just as your body imperfectly regulates its temperature. Your body maintains a stable temperature because your brain stem sends out commands to your body to speed up or slow down processes that create or disperse heat. The Earth has no body or brain. It seems, however, to have a disembodied, mindless, but largely successful kind of self-regulation. This is why I have titled the book Life of Earth, not Life on Earth.

Many scientists have conceptualized this network of life as Gaia. These scientists are not offering sacrifices at a Delphic Oracle or hallucinating on the carbon dioxide in the oracular caves. They are not nature worshippers. To them, Gaia is a personal name for a living planet that is not, or not quite, a person. Earth does not care for its organisms as would a mother; in fact, some scientists, such as planetary scientist Peter Ward, characterize Earth as being like Medea, rather than Gaia. Medea, another character from Greek mythology, was the vengeful wife of Jason, whom she tricked into eating his own (and her) children. The network of life has often, like a good mother, enhanced the welfare of its inhabitants, but sometimes it has made conditions worse for them. Nevertheless we, and all other species, depend on this web of life as surely as any animal depends on its mother.

LUCKY GAIA

One day in 1950, over lunch with his scientific colleagues, physicist Enrico Fermi heard someone speculate about how many advanced civilizations there must be out in space. Fermi quipped, "So, where are they?" He meant that if there were many advanced civilizations, some of them must be more advanced than we are, they must have invented space travel, and at least some of them should have contacted us by now. This has come to be known as "Fermi's Paradox." One answer to this paradox is that there are so few advanced civilizations in the universe that they have not found us yet and probably never will. According to this view, sometimes called the "Lucky Gaia" hypothesis, Earthlike planets, Gaia planets, might be very rare. Very few planets have been as lucky as Earth.

It cannot be denied that, from the very beginning, Gaia has been very, very, very lucky. The network of life arose and developed to its present astounding complexity as a result of a vanishingly rare conjunction of circumstances presumably enjoyed by very few other planets in the universe.

Planets are not at all rare in the universe. More than four hundred planets have been detected orbiting nearby stars. Astronomers can detect these planets and calculate their masses and orbit distances by the fluctuations in light intensity and by the slight swaying movements of the star itself. In one case, scientists were able to generate an image of the planet. Most of these planets have been what astronomers call "hot Jupiters," that is, large gaseous planets orbiting very close to their stars. They resemble a double-star system in which the smaller star never ignited. But a few of the planets are believed to be rocky like Venus, Earth, and Mars. It is therefore likely that rocky planets are common in the universe.

Earth's luck goes far beyond just being a rocky planet, according to the Rare Earth hypothesis of planetary scientists Peter Ward and Donald Brownlee. We can begin, Ward and Brownlee say, by thanking our lucky star, the sun.

Thank Our Lucky Star

First, the sun is a calm and stable star. Many stars, such as the Cepheid variable stars mentioned earlier, fluctuate wildly in their energy output: they are small and dim; then as quickly as one day to a couple of months later, they become larger and more than twice as luminous. Such pulsations in energy may prevent life from ever getting started on any planets that revolve around variable stars. In contrast, the sun has been stable for billions of years. Not perfectly stable, of course. The sun has had occasional "coronal mass ejections," in which it propels energy and particles from its outer layer out into the solar system. One of these mass ejections, on September 1, 1859, was strong enough that it shut down the telegraph systems in the United States and Europe and caused auroras to occur in the skies of even tropical regions. The sun also has an eleven-year sunspot cycle. These variations, however, have not had much effect on Earth. Coronal ejections have not been known to have ever harmed life on Earth (no organisms were harmed when the telegraphs shut down), and solar intensity shifts by only 0.1 percent during the sunspot cycle. The sun has, in fact, changed its energy output over the billions of years of its existence. It has increased the intensity of its radiation by about...

Details zur Ausgabe

• Verlag: Prometheus Books
• Erscheinungsdatum: 2010
• Sprache: Englisch
• ISBN 10: 1616142251
• ISBN 13: 9781616142254
• Einband: Gebundene Ausgabe
• Anzahl der Seiten: 255
• Kontakt zum Hersteller: Nicht verfügbar
• Verantwortliche Person: Simon and Schuster Netherlands BV, GPSR Europäische Union; info@simonandschuster.nl; ; Herculesplein 96; Utrecht; 3584 AA; Niederlande