New discoveries of ancient vertebrates, filling in gaps in the fossil record, are quickly eroding the traditionally recognized differences between the principal groups of vertebrates—for example, between dinosaurs and birds—and radically changing our understanding of the evolutionary history of the major group of animals to which our species belongs. This book describes this changing scientific landscape and contributes to the revolution in our knowledge of the developmental mechanisms that underlie evolutionary transformation.
During evolution there have been several major changes in the way genetic information is organized and transmitted from one generation to the next. These transitions include the origin of life itself, the first eukaryotic cells, reproduction by sexual means, the appearance of multicellular plants and animals, the emergence of cooperation and of animal societies. This is the first book to discuss all these major transitions and their implications for our understanding of evolution.Clearly written and illustrated with many original diagrams, this book will be welcomed by students and researchers in the fields of evolutionary biology, ecology, and genetics.
The factors that influenced the evolution of the vertebrates are compared with the importance of variation and selection that Darwin emphasised in this broad study of the patterns and forces of evolutionary change.
How did flying birds evolve from running dinosaurs, terrestrial trotting tetrapods evolve from swimming fish, and whales return to swim in the sea? These are some of the great transformations in the 500-million-year history of vertebrate life. And with the aid of new techniques and approaches across a range of fields—work spanning multiple levels of biological organization from DNA sequences to organs and the physiology and ecology of whole organisms—we are now beginning to unravel the confounding evolutionary mysteries contained in the structure, genes, and fossil record of every living species. This book gathers a diverse team of renowned scientists to capture the excitement of these new discoveries in a collection that is both accessible to students and an important contribution to the future of its field. Marshaling a range of disciplines—from paleobiology to phylogenetics, developmental biology, ecology, and evolutionary biology—the contributors attack particular transformations in the head and neck, trunk, appendages such as fins and limbs, and the whole body, as well as offer synthetic perspectives. Illustrated throughout, Great Transformations in Vertebrate Evolution not only reveals the true origins of whales with legs, fish with elbows, wrists, and necks, and feathered dinosaurs, but also the relevance to our lives today of these extraordinary narratives of change.
This book encourages readers to view similarities and differences in various species as fundamental to a comprehensive understanding of nervous systems.
'Patterning in Vertebrate Development' is a new volume in the 'Frontiers in Molecular Biology' series which provides a range of comprehensive, and authoritative reviews of current research into patterning, a fundamental process in developmental biology.
The vertebrate integument arose about 450 million years ago as an ‘armour’ of dermal bony plates in small, jawless fish-like creatures, informally known as the ostracoderms. This book reviews the major changes that have occurred in the vertebrate integument from its beginnings to the present day. Critical questions concerning the origin, structure and functional biology of the bony integument are discussed and intrinsically linked to major steps in vertebrate evolution and phylogeny—the origin of jaws and the origin of teeth. The discussions include the origins of mineralization of major vertebrate skeletal components such as the dermatocranium, branchial arches and vertebral column. The advances that led to the origin of modern fishes and their phylogenetic development are reviewed and include the evolution of fins and replacement of the bony plates with several types of dermal scales. The evolution of reptiles saw a major transformation of the integument, with the epidermis becoming the protective outermost layer, from which the scales arose, while the dermis lay below it. The biological significance of the newly-evolved β-keratin in reptilian scales, among the toughest natural materials known, is discussed in the context of its major contribution to the great success of reptiles and to the evolution of feathers and avian flight. The dermis in many vertebrates is strengthened by layers of oppositely oriented cross-fibres, now firmly entrenched as a design principle of biomechanics. Throughout the book conventional ideas are discussed and a number of new hypotheses are presented in light of the latest developments. The long evolutionary history of vertebrates indicates that the significance of the Darwinian concept of “survival of the fittest” may be overstated, including in our own mammalian origins and that chance often plays a major role in evolutionary patterns. Extensive illustrations are included to support the verbal descriptions. Professor Theagarten Lingham-Soliar is in the Department of Life Sciences at the University of KwaZulu-Natal.
It is said that "necessity is the mother of invention". To be sure, wheels and pulleys were invented out of necessity by the tenacious minds of upright citi zens. Looking at the history of mankind, however, one has to add that "Ieisure is the mother of cultural improvement". Man's creative genius flourished only when his mind, freed from the worry of daily toils, was permitted to entertain apparently useless thoughts. In the same manner, one might say with regard to evolution that "natural selection mere(y tnodifted, while redundanry created". Natural selection has been extremely effective in policing alleHe mutations which arise in already existing gene loci. Because of natural selection, organisms have been able to adapt to changing environments, and by adaptive radiation many new species were created from a common ancestral form. Y et, being an effective policeman, natural selection is extremely conservative by nature. Had evolution been entirely dependent upon natural selection, from a bacterium only numerous forms of bacteria would have emerged. The creation of metazoans, vertebrates and finally mammals from unicellular organisms would have been quite impos sible, for such big leaps in evolution required the creation of new gene loci with previously nonexistent functions. Only the cistron which became redun dant was able to escape from the relentless pressure of natural selection, and by escaping, it accumulated formerly forbidden mutations to emerge as a new gene locus.
This text discusses whether the origin of radically new kinds of organisms - new higher taxa - are the result of normal Darwinian evolution proceeding, or whether unusual genetic processes and/or special environmental circumstances are necessary.
