Time Frames

Time Frames: The Evolution of Punctuated Equilibria

NILES ELDREDGE
Copyright Date: 1985
Pages: 240
https://www.jstor.org/stable/j.ctt7zv155
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    Time Frames
    Book Description:

    Scientists have recently begun to question one of the pillars of modern thought--Charles Darwin's theory of evolution. Certainly evolution occurs; but if it is a slow, continuous process by which one species gradually modifies itself into a new one, as Darwin believed, why are there so many missing links in the fossil records? Two eminent scientists, Niles Eldredge and Stephen Jay Gould, startled the world by challenging Darwin's cherished beliefs proposing instead that once a species has evolved it rarely undergoes change, and that the evolution of new species occurs only periodically, in relatively rapid spurts. In Time Frames Niles Eldredge explains how his own work with trilobite fossils led him to this unexpected conclusion, and describes the fascinating development of the new theory of punctuated equilibria.

    Originally published in 1989.

    ThePrinceton Legacy Libraryuses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

    eISBN: 978-1-4008-6029-6
    Subjects: Ecology & Evolutionary Biology

Table of Contents

  1. Front Matter
    (pp. 1-8)
  2. Table of Contents
    (pp. 9-12)
  3. PREFACE
    (pp. 13-16)
  4. 1 EVOLUTION NOWADAYS
    (pp. 17-37)

    The California coastline is volatile. The huge Pacific chunk of crustal plate surfaces as a thin rind of the North American continent, a sliver of rock running from Mexico up through L.A. and San Francisco before slipping once again below the waves. In the last 120 million years this outer rim of California coast has moved north perhaps as much as 350 miles—a rate of .2 inches per year. But that is only the average rate: what really happens is far more sporadic. Tension constantly mounts as the Pacific plate tries to slip north past the rest of the...

  5. 2 ANCIENT SEAS AND EVOLUTIONARY FANTASIES
    (pp. 38-56)

    These are unusual times. The continents stand high and dry, and though they occupy a mere 29 percent of the earth’s surface—the rest given over to the seas—yet it is not the normal course of things for so much land to be exposed. It is far more usual to find the lands flooded, covered with a thin veneer of seawater. The great polar ice caps have locked up a tremendous volume of water, and sea level has been rising for the last 20,000 years or so as the latest glacial sheets retreated. But the ice caps, with their...

  6. 3 AT SEA IN THE AMERICAN MIDWEST
    (pp. 57-91)

    The European–North American collision that began about 380 million years ago did more than change the face of the globe: it also grossly affected the face of life in North America. Many of the Hamilton species that were to dominate American life for the next 8 million years were immigrants from Europe and Africa, derived from species living in the early Middle Devonian whose fossils now come from the Rhine Valley in Germany and the desert reaches of what was, until recently, the Spanish Sahara.Phacops africanus,a species closely related toP. rana,is known from northern Africa,...

  7. 4 THE EMERGENCE OF PUNCTUATED EQUILIBRIA: SPECIATION AND EVOLUTIONARY CHANGE IN ANCIENT SEAS
    (pp. 92-122)

    There is an old saying “The present is the key to the past.” Charles Lyell, who founded the modern science of geology with the publication of his three-volumePrinciples of Geology(1830–33), enjoined his colleagues to use their heads and common sense: we can understand much of the earth’s past if we simply assume that the processes we see acting around us today were also operating in the remote past.* Thus we see stream beds laden with silt and clay, and a little investigation shows us that the particles come from soils and, ultimately, bedrock somewhere upstream. Water runs...

  8. 5 PARADOX FOUND: ADAPTATION AND MACROEVOLUTION
    (pp. 123-151)

    There are some thirty-eight active volcanoes on Java. Sitting on the edge of a subduction zone, where oceanic crust is being sucked down and heated under the major islands of the Indonesian archipelago, the volcanoes are vents for some of that deep-seated mélange of molten rock. Though much of Java is now dedicated to rice cultivation, the fuming volcanoes and lush greenery still present a distinctly primitive feel. And one wonders whyHomo sapiens,in all its rich cultural and ethnic diversity, is there at all. What ever happened to Java man?

    “Java man” was the discovery of a Dutch...

  9. 6 PARADOX LOST: SPECIES AT PLAY IN THE EVOLUTIONARY GAME
    (pp. 152-179)

    Frustrating occupation, trying to think about fossils in evolutionary terms. On the one hand we have a theory deeply rooted in genetics, and on the other the scattered and partial remains of thoroughly dead organisms. The patterns of stasis and change that do come through this filter of death and destruction really are so gross that even if we miraculously knew the genetic basis of the features we see in some of our fossil specimens, there would still be the horrendous difficulty of specifying just what happened to those genes during the eons that elapsed between our imaginary “genetical” fossil...

  10. 7 WHERE TO? WHAT NEXT?
    (pp. 180-192)

    In Esmeralda County, Nevada, just east of the California border, what’s left of the advent of complex life is there in the rocks for all who are curious. Now a barren and rather desolate place, with dry scrubland lying among rocky hills, it presents a seeming irony as a locale where the beginnings of life’s big explosion would crop up. And yet the Joshua trees, hawks and prairie rattlers, the coyotes and mule deer are all here; the place is by no means lifeless. And just a few miles away, in the White-Inyo Mountains, stand the bristlecone pines, those hardy,...

  11. APPENDIX: PUNCTUATED EQUILIBRIA: AN ALTERNATIVE TO PHYLETIC GRADUALISM
    (pp. 193-224)
    Niles Eldredge and Stephen Jay Gould
  12. BIBLIOGRAPHY
    (pp. 225-230)
  13. INDEX
    (pp. 231-240)