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Preface to the Second Edition

Published online by Cambridge University Press:  14 January 2010

Jeffrey S. Levinton
Affiliation:
State University of New York, Stony Brook
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Summary

In the past decade, my vision of macroevolution has taken hold and will dominate macroevolutionary thinking in the next decade as well, although I can hardly say that I had much to do with its ascent. I defined macroevolution to be the sum of those processes that explain the character-state transitions that diagnose evolutionary differences of major taxonomic rank. I focused on the individual, development, and models explaining the evolution of form. Previously, the definition that held sway was: evolution above the species level. This is not just a definition: It directed macroevolutionary studies to speciation rates, the importance of speciation, and even models that argue that something about the speciation process is the motor of morphological evolution.

The focus on above-species-level processes has given us some very exciting results, such as the late Jack Sepkoski's relentless pursuit of a large-scale data base to provide a biodiversity thermometer for earth processes. But it leaves out much; I would say it omits the most interesting stuff. I would say that models emphasizing speciation and sorting among species have proven unimportant, even if the obvious effects of extinction as a filter are still self-evident.

In the past decade, the field has diverted strongly to studies that explain character transformation. This has been aided by the entry of phylogenetic methods in paleontological studies. Sure, there were a few phylogenetic studies done with fossil groups before 1990, but now they are dominant. Indeed, some phylogenetic systematists actively forestalled the use of fossil groups in constructing phylogenies, but paleontologists came back and even successfully introduced stratigraphic order of appearance as a credible approach to tree construction.

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Publisher: Cambridge University Press
Print publication year: 2001

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