After volume 33, this book series was replaced by the journal "Evolutionary Biology." Please visit www.springer.com/11692 for further information. This volume continues bringing to readers the findings of eminent evolutionary biologists and paleobiologists. Among the topics discussed in this book are the origin of the dermal skeleton in conodont chordates, patterns of nucleotide substitution and codon usage in plasmid DNA evolution, a model to explain phenotype stability in functional systems, and inter-island speciation of Hawaiian biota.

After volume 33, this book series was replaced by the journal "Evolutionary Biology." Please visit www.springer.com/11692 for further information. The current volume includes articles on the conceptual relationship of ontogeny, phylogeny, and classification; correlation studies of spatial patterns of genetic variation; and the evolution of flower display and reward.

After volume 33, this book series was replaced by the journal "Evolutionary Biology." Please visit www.springer.com/11692 for further information. The nature of science is to work on the boundaries between the known and the unknown. These boundaries shift as new methods are developed and as new concepts are elaborated (e.g., the theory of the gene, or more recently, the coalescence framework in population genetics). These tools allow us to address questions that were previously outside the realm of science, and, as a consequence, the boundary between the knowable and unknowable has shifted. A study of limits should reveal and clarify the boundaries and make sharper the set of questions. This book examines and analyzes these new limits as they are applied to evolutionary biology and population genetics. It does this by framing the analysis within four major classes of problems - establishing the fact of evolution; understanding the evolutionary pathways that led to today's biological world; mechanisms of evolutionary change (e.g., models of social behavior, sexual selection, macro evolution); and, finally, prediction.

This volume is the twenty-ninth in this series, which includes twenty-eight numbered volumes and one unnumbered supplement. The editors continue to focus on critical reviews, commentaries, original papers, and controversies in of the reviews range from anthropology to evolutionary biology. The topics molecular evolution, population biology to paleobiology. Recent volumes have included a broad spectrum of chapters on such subjects as population biology, comparative morphology, paleobiology, molecular phy logenetics, developmental evolutionary biology, systematics, and the history of evolutionary biology. The editors continue to solicit manuscripts in all areas of evolutionary biology. Manuscripts should be sent to anyone of the following: Max K. Hecht, Department of Biology, Queens College of the City University of New York, Flushing, New York 11367; Ross 1. MacIntyre, Department of Genetics and Development, Cornell University, Ithaca, New York 14853; or Michael T. Clegg, Department of Botany and Plant Sciences, University of California, Riverside, California 92521. vii Contents 1. Homology and Embryonic Development Brian K. Hall Introduction .............................................. 1 A Brief History of the Concept of Homology ................. 1 von Baer's Laws ........................................ 4 Germ Layers and Ernst Haeckel ............................ 6 Embryology and Homology ............................... 7 Homology: An Unsolved Problem ............................ 8 Latent Homology ........................................ 8 Serial Homology ........................................ 9 Common Origins and Common Inductions ..................... 12 Mechanisms of Gastrulation ............................... 13 Origin of the Alimentary Canal ............................ 14 Origin of Germ Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 . . . . . . . . . . Induction of Meckel's Cartilage ............................ 15 Induction of the Lens of the Eye ........................... 16 Development of Internal and External Cheek Pouches .......... 18 Selection for Increased Tail Length in Mice .................. 19 Regeneration and Homology .... . . . . . . . . . . . . . . . . . . . . 20 . . . . . . ."

Human activities influence the chemical and physical properties of the atmosphere; examples are increases in troposphere concentrations of ozone, carbon dioxide, oxides of nitrogen and sulfur, heavy metals and UV-B radiation. Many of these changes can alter the physiological status of terrestrial vegetation through either inhibition or enhancement of growth and reproduction, thereby influencing the ability of sensitive plants to compete for limited resources. As a result, air pollution stress may be changing the genetic structure of plant populations. In this book, leading researchers with a broad, interdisciplinary range of expertise discuss the known and measurable effects of pollution on terrestrial vegetation within the framework of ecological genetics, as well as suitable experimental methodologies to analyze the often novel or unusual effects of such environmental stresses. For environmental researchers and managers, Ecological Genetics and Air Pollution will be a welcomed introduction to this field of growing importance for long-term ecological studies.

After volume 33, this book series was replaced by the journal "Evolutionary Biology." Please visit www.springer.com/11692 for further information.

This volume is the 33rd in this series, which includes 32 numbered volumes and an unnumbered supplement. Several special volumes have also been published as separate monographs. This volume, like the others in the series, has chapters devoted to a broad spectrum of topics. Indeed, the editors continue to solicit manuscripts on subjects covered by the encompassing rubric of Evolutionary Biology.

"Volume 33 continues the grand tradition of Evolutionary Biology in being the most comprehensive series in the field. The chapters are always up-to-date, informative, and stimulating; sometimes infuriating. Just what good scientific literature should be Particularly attractive is the free-wheeling spirit of the series: no style or length is imposed. If you want to remain cognizant of contemporary evolutionary advances in general and have time to read only one volume a year outside your own specialty, make it Evolutionary Biology."
(Jeffrey R. Powell, Ph.D., Yale University)

After volume 33, this book series was replaced by the journal "Evolutionary Biology." Please visit www.springer.com/11692 for further information.

This volume is the 33rd in this series, which includes 32 numbered volumes and an unnumbered supplement. Several special volumes have also been published as separate monographs. This volume, like the others in the series, has chapters devoted to a broad spectrum of topics. Indeed, the editors continue to solicit manuscripts on subjects covered by the encompassing rubric of Evolutionary Biology.

"Volume 33 continues the grand tradition of Evolutionary Biology in being the most comprehensive series in the field. The chapters are always up-to-date, informative, and stimulating; sometimes infuriating. Just what good scientific literature should be Particularly attractive is the free-wheeling spirit of the series: no style or length is imposed. If you want to remain cognizant of contemporary evolutionary advances in general and have time to read only one volume a year outside your own specialty, make it Evolutionary Biology."
(Jeffrey R. Powell, Ph.D., Yale University)

After volume 33, this book series was replaced by the journal "Evolutionary Biology." Please visit www.springer.com/11692 for further information.

The nature of science is to work on the boundaries between the known and the unknown. These boundaries shift as new methods are developed and as new concepts are elaborated (e.g., the theory of the gene, or more recently, the coalescence framework in population genetics). These tools allow us to address questions that were previously outside the realm of science, and, as a consequence, the boundary between the knowable and unknowable has shifted. A study of limits should reveal and clarify the boundaries and make sharper the set of questions. This book examines and analyzes these new limits as they are applied to evolutionary biology and population genetics. It does this by framing the analysis within four major classes of problems - establishing the fact of evolution; understanding the evolutionary pathways that led to today's biological world; mechanisms of evolutionary change (e.g., models of social behavior, sexual selection, macro evolution); and, finally, prediction.

After volume 33, this book series was replaced by the journal "Evolutionary Biology." Please visit www.springer.com/11692 for further information.

This volume continues bringing to readers the findings of eminent evolutionary biologists and paleobiologists. Among the topics discussed in this book are the origin of the dermal skeleton in conodont chordates, patterns of nucleotide substitution and codon usage in plasmid DNA evolution, a model to explain phenotype stability in functional systems, and inter-island speciation of Hawaiian biota.

After volume 33, this book series was replaced by the journal "Evolutionary Biology." Please visit www.springer.com/11692 for further information.

Volume 30 brings readers up to date on the investigation of eminent evolutionary biologists and paleobiologists. Contributions explore such topics as

• Adaptation in Drosophila and the role of cytochrome P450s
• Population genetics and species conservation of the cheetah
• germ-layer theory
• assymetry in the mammalian skeleton
• genetic diversity of marine fish
• the phenomenon of industrial melanism
• the variation in lizard cranal kinesis.

Other chapters focus on such issues as overdominance and its relation to higher mutation-rate estimates and the use of molecular clocks in determining the rate of nucleotide substitution in higher plants.

After volume 33, this book series was replaced by the journal "Evolutionary Biology." Please visit www.springer.com/11692 for further information. In Volume 29, internationally acclaimed researchers address a broadrange of topics including the organization of eukaryotic genes, evolution of Drosophila mating systems, and evolutionary-developmental approaches to fin/limb transformation.

"The present book is intended as a progress report on the] synthetic approach to evolution as it applies to the plant kingdom." With this simple statement, G. Ledyard Stebbins formulated the objectives of "Variation and Evolution" in Plants, published in 1950, setting forth for plants what became known as the "synthetic theory of evolution" or "the modern synthesis." The pervading conceit of the book was the molding of Darwin's evolution by natural selection within the framework of rapidly advancing genetic knowledge.
At the time, "Variation and Evolution" in Plants significantly extended the scope of the science of plants. Plants, with their unique genetic, physiological, and evolutionary features, had all but been left completely out of the synthesis until that point. Fifty years later, the National Academy of Sciences convened a colloquium to update the advances made by Stebbins.
This collection of 17 papers marks the 50th anniversary of the publication of Stebbins' classic. Organized into five sections, the book covers: early evolution and the origin of cells, virus and bacterial models, protoctist models, population variation, and trends and patterns in plant evolution.