The Evolution of Individuality

The Evolution of Individuality

LEO W. BUSS
Copyright Date: 1987
Pages: 220
https://www.jstor.org/stable/j.ctt7zvwtj
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  • Book Info
    The Evolution of Individuality
    Book Description:

    Leo Buss expounds a general theory of development through a simple hierarchical extension of the synthetic theory of evolution. He perceives innovations in development to have evolved in ancestral organisms where the germ line was not closed to genetic variation arising during the course of ontogeny.

    Originally published in 1988.

    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: 978-1-4008-5871-2
    Subjects: Biological Sciences

Table of Contents

  1. Front Matter
    (pp. i-iv)
  2. Table of Contents
    (pp. v-vi)
  3. PREFACE
    (pp. vii-x)
  4. ACKNOWLEDGMENTS
    (pp. xi-xii)
  5. FIGURE SOURCES
    (pp. xiii-xv)
  6. AUGUST WEISMANN’S LEGACY
    (pp. 1-26)

    The Darwinian notion of evolution as a process directed by selection upon heritable variation has not been effectively challenged since Darwin first articulated it. Evolution by common descent had become established as undeniable fact within decades of the publication of theOrigin of Species. Yet, the original theory lacked any mechanism by which variation might be inherited. Nor did it provide any assurance that such a mechanism, if discovered, could also direct the myriad details of ontogeny. Biologists, content that evolution had occurred, were understandably far from any agreement onhowit had occurred. Turmoil marked the late nineteenth and...

  7. THE EVOLUTION OF DEVELOPMENT
    • [Introduction]
      (pp. 27-31)

      Development has traditionally been viewed as a cooperative enterprise. The zygote gives rise to clones of cells which, by a complex interplay of mutual interactions, faultlessly orchestrate the production of a new individual. While the cooperative model is an appealing characterization of development in extant taxa, it is inappropriate to view the processes which gave rise to developmental programs as cooperative. The opposite is more likely the case. At the dawn of metazoan life, the germ line was not determined at the outset of ontogeny. Those cells which ultimately gave rise to new individuals had to earn their position in...

    • THE CONSERVATISM OF EARLY ONTOGENY
      (pp. 33-68)

      The ontogeny of metazoans begins in a highly stereotyped fashion. Whether the resulting individual is to develop into a coral or a clam, the initial stages of metazoan development display a marked similarity. The zygote typically cleaves in either a spiral or radial fashion to yield a spherical ball of cells, the blastula, which undergoes a series of morphogenetic movements producing a multilayered structure, the gastrula. The zygote of a coral cleaves somewhat differently from that of the clam, and the gastrula is formed by rather different patterns of cell movement, but both undergo manifestly similar transformations of cell division,...

    • THE DIVERSITY OF LATE ONTOGENY
      (pp. 69-118)

      After gastrulation, the initially stereotyped development of metazoan embryos disappears into complex, taxon-specific modes of elaboration from which one of several discrete body plans emerges. These fundamental “bauplans” evolved rapidly and, inexplicably, became fixed. The first unicellular eukaryotes are known from the Bitter Springs Formation (0.9 b.y.b.p.); yet metazoans clearly recognizable as members of extant phyla are found only 200 million years later in the Ediacara Formation (0.7 b.y.b.p.). The fundamental body plans of extant taxa swam, floated, and crawled in the early Paleozoic oceans. Modifications upon existing plans certainly arose: land was conquered, flight evolved, and myriad species-specific complexities...

  8. LIFE CYCLE EVOLUTION
    (pp. 119-168)

    Evolution can occur only if life cycles. Life itself does not require reproduction—sterile individuals are no less living entities for their misfortune—but life without reproduction is surely doomed. Only if life reproduces itself can it persist indefinitely. And only via reproduction can natural selection have products on which to act. Life cycles are thesine qua nonof evolution. Yet, as George C. Williams says, “The main work of providing a workable theoretical structure for understanding the enormous diversity of life cycles remains to be done.”¹ The condition is curious; on the one hand we have a modern...

  9. THE EVOLUTION OF HIERARCHICAL ORGANIZATION
    (pp. 169-198)

    It is neither bold, nor even particularly insightful, to predict that this century will end as did the last—in an attempt to frame a consistent theoretical superstructure that merges development, genetics, and evolution. The close of the nineteenth century brought to an end an era of speculation on heredity, on development, and on phylogeny. Gone were the inheritance theories of Weismann and the biogenic law of Haeckel, displaced by the empirical tradition taking hold in the new science of genetics and Roux’s experimental approach to embryology. Nearly a century of empiricism has now passed. The genetic material is known...

  10. AUTHOR INDEX AND REFERENCE KEY
    (pp. 199-202)
  11. TAXONOMIC INDEX
    (pp. 203-203)
  12. Back Matter
    (pp. 204-204)