All protists, fungi, animals, and plants on Earth are eukaryotes. Their cells possess membrane-bound organelles including a nucleus and mitochondria, distinct cytoskeletal features, and a unique chromosome structure that permits them to undergo mitosis or meiosis. The emergence of eukaryotic cells from prokaryotic ancestors about 2 billion years ago was a pivotal evolutionary transition in the history of life on Earth. But the change was abrupt, and few clues exist as to the nature of the intermediate stages. Written and edited by experts in the field, this collection from Cold Spring Harbor Perspectives in Biology examines evolutionary scenarios that likely led to the emergence and rapid evolution of eukaryotes. Contributors review the mechanisms, timing, and consequences of endosymbiosis, as well as molecular and biochemical characteristics of archaea and bacteria that may have contributed to the first eukaryotic lineage. They explore all of the available evidence, including clues from the fossil record and comparative genomics, and formulate ideas about the origin of genomic characteristics (e.g., chromatin and introns) and specific cellular features (e.g., the endomembrane system) in eukaryotes. Topics such as the origins of multicellularity and sex are also covered. This volume includes discussion of multiple evolutionary models that warrant serious attention, as well as lively debate on some of the most contentious topics in the field. It will thus be fascinating reading for evolutionary biologists, cell and molecular biologists, paleobiologists, and all who are interested in the history of life on Earth.

A reconceptualization of origins research that exploits a modern understanding of non-covalent molecular forces that stabilize living prokaryotic cells. Scientific research into the origins of life remains exploratory and speculative. Science has no definitive answer to the biggest questions--"What is life?" and "How did life begin on earth?" In this book, Jan Spitzer reconceptualizes origins research by exploiting a modern understanding of non-covalent molecular forces and covalent bond formation--a physicochemical approach propounded originally by Linus Pauling and Max Delbrück. Spitzer develops the Pauling-Delbrück premise as a physicochemical jigsaw puzzle that identifies key stages in life's emergence, from the formation of first oceans, tidal sediments, and proto-biofilms to progenotes, proto-cells and the first cellular organisms.

Prokaryotes are profoundly original, highly efficient microorganisms that have played a decisive role in the evolution of life on Earth. Although disjunct, taken together their cells form one global superorganism or biological system. One of the results of their non-Darwinian evolution has been the development of enormous diversity and bio-energetic variety. Prokaryotic cells possess standardized mechanisms for easy gene exchanges (lateral gene transfer) and they can behave like receiving and broadcasting stations for genetic material. Ultimately, the result is a global communication system based on the prokaryotic hereditary patrimony, by analogy, a two-billion-year-old world wide web for their benefit. Eukaryotes have evolved from the association of at least three complementary prokaryotic cells, and their subsequent development has been enriched and accelerated by symbioses with other prokaryotes. One of these symbioses was responsible for the origin of vascular plants which transformed vast sections of the continental surface of the Earth from deserts to areas with luxuriant, life-supporting vegetation. All forms of life on our planet are directly or indirectly sustained and enriched by the positive contribution of prokaryotes. Sorin Sonea and L�o G. Mathieu have been professors at the Department of Microbiology and Immunology (Faculty of Medicine) at the Universit� de Montr�al. They have long been advocates of the ideas presented in this book.

Black & white print. Concepts of Biology is designed for the typical introductory biology course for nonmajors, covering standard scope and sequence requirements. The text includes interesting applications and conveys the major themes of biology, with content that is meaningful and easy to understand. The book is designed to demonstrate biology concepts and to promote scientific literacy.

This book is about the various roles of bioactive ceramides and other sphingolipids in cellular biology. The enigmatic biophysical and biochemical properties of ceramides and their propensity to influence membranes whether as rafts or protein-permeable channels are heavily discussed. Metabolism of ceramides and their metabolites is also focused with ceramide synthase family of proteins being a target of extensive review. Ceramide 1-phosphate and other sphingolipids are also presented in cellular physiology and pathophysiology. Prokaryotic origins of mitochondria at the level of membranes and the occurrence of apoptosis in bacteria are presented. Many aspects of ceramide and sphingolipid biology are addressed in this book. Its focus is the metabolism of ceramide in normal and diseased states and the biophysical and biochemical mechanisms governing the bioactivity of these molecules. Sphingolipid research has surged over the past thirty years and this book gathers the recent findings of various aspects of sphingolipid biochemistry. World-renowned scientists from the field of lipid biology, specifically sphingolipid biochemistry, were gathered to write this book. Scholars from most continents of the globe committed to write diligently about their expertise and the newest findings in the relevant fields. This book came to fruition after almost a year and a half of laborious preparation and diligent writings. This book is targeted to the experienced reader who is looking to read about the various aspects of bioactive ceramide signaling, as well as to the newcomer into the field, as the topics are explained in concise yet very informative manner. The authors and editor wish all readers a pleasant time reading this volume, and are adamant that this book will meet all expectations.

This comprehensive history of cell evolution “deftly discusses the definition of life” as well as cellular organization, classification and more (San Francisco Book Review). The origin of cells remains one of the most fundamental mysteries in biology, one that has spawned a large body of research and debate over the past two decades. With In Search of Cell History, Franklin M. Harold offers a comprehensive, impartial take on that research and the controversies that keep the field in turmoil. Written in accessible language and complemented by a glossary for easy reference, this book examines the relationship between cells and genes; the central role of bioenergetics in the origin of life; the status of the universal tree of life with its three stems and viral outliers; and the controversies surrounding the last universal common ancestor. Harold also discusses the evolution of cellular organization, the origin of complex cells, and the incorporation of symbiotic organelles. In Search of Cell History shows us just how far we have come in understanding cell evolution—and the evolution of life in general—and how far we still have to go. “Wonderful…A loving distillation of connections within the incredible diversity of life in the biosphere, framing one of biology’s most important remaining questions: how did life begin?”—Nature