The Arthur M. Sackler Colloquia of the National Academy of Sciences address scientific topics of broad and current interest, cutting across the boundaries of traditional disciplines. Each year, four or five such colloquia are scheduled, typically two days in length and international in scope. Colloquia are organized by a member of the Academy, often with the assistance of an organizing committee, and feature presentations by leading scientists in the field and discussions with a hundred or more researchers with an interest in the topic. Colloquia presentations are recorded and posted on the National Academy of Sciences Sackler colloquia website and published on CD-ROM. These Colloquia are made possible by a generous gift from Mrs. Jill Sackler, in memory of her husband, Arthur M. Sackler.
Genetic studies aimed at understanding the origin of species are dominating major scientific journals. In the past decade, genetic tools that were previously available only in model systems have become accessible to investigators working on nearly all species. Concurrent with these technical advances has been an increase in understanding of both the importance of considering the ecological context of speciation and testing hypotheses about causes for species formation. Many recent studies suggest a prominent role of sexual selection in species formation. These advances have produced a need for a synthesis of what we now understand about speciation, and perhaps more importantly, where we should go from here. In this volume, several leading investigators and rising stars have contributed reviews and/or novel primary research findings aimed at understanding the ultimate mystery on which Darwin named his most famous and influential book. Fundamental to the origin of species is the evolution of mate choice systems. This collection of papers discusses burgeoning genetic, evolutionary, and ecological approaches to understanding the origins of mating discrimination and causes of premating reproductive isolation both within and between species. The individual contributions span a wide spectrum of disciplines, taxa, and ideas (some controversial). This synthesis brings together several of the most recent ideas with supporting empirical data. This book will be of particular interest to both undergraduate and postgraduate researchers and students and researchers in the field of evolutionary biology, genetics and animal behaviour.
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.
"The last ten years have seen an explosion of activity in the application of molecular biological techniques to evolutionary and ecological studies. This volume attempts to summarize advances in the field and place into context the wide variety of methods available to ecologists and evolutionary biologists using molecular techniques. Both the molecular techniques and the variety of methods available for the analysis of such data are presented in the text. The book has three major sections - populations, species and higher taxa. Each of these sections contains chapters by leading scientists working at these levels, where clear and concise discussion of technology and implication of results are presented. The volume is intended for advanced students of ecology and evolution and would be a suitable textbook for advanced undergraduate and graduate student seminar courses." -- Publisher.
The average person can name more bird species than they think, but do we really know what a bird “species” is? This open access book takes up several fascinating aspects of bird life to elucidate this basic concept in biology. From genetic and physiological basics to the phenomena of bird song and bird migration, it analyzes various interactions of birds – with their environment and other birds. Lastly, it shows imminent threats to birds in the Anthropocene, the era of global human impact. Although it seemed to be easy to define bird species, the advent of modern methods has challenged species definition and led to a multidisciplinary approach to classifying birds. One outstanding new toolbox comes with the more and more reasonably priced acquisition of whole-genome sequences that allow causative analyses of how bird species diversify. Speciation has reached a final stage when daughter species are reproductively isolated, but this stage is not easily detectable from the phenotype we observe. Culturally transmitted traits such as bird song seem to speed up speciation processes, while another behavioral trait, migration, helps birds to find food resources, and also coincides with higher chances of reaching new, inhabitable areas. In general, distribution is a major key to understanding speciation in birds. Examples of ecological speciation can be found in birds, and the constant interaction of birds with their biotic environment also contributes to evolutionary changes. In the Anthropocene, birds are confronted with rapid changes that are highly threatening for some species. Climate change forces birds to move their ranges, but may also disrupt well-established interactions between climate, vegetation, and food sources. This book brings together various disciplines involved in observing bird species come into existence, modify, and vanish. It is a rich resource for bird enthusiasts who want to understand various processes at the cutting edge of current research in more detail. At the same time it offers students the opportunity to see primarily unconnected, but booming big-data approaches such as genomics and biogeography meet in a topic of broad interest. Lastly, the book enables conservationists to better understand the uncertainties surrounding “species” as entities of protection.
Biology was forged into a single, coherent science only within living memory. In this volume the thinkers responsible for the "modern synthesis" of evolutionary biology and genetics come together to analyze that remarkable event. In a new Preface, Ernst Mayr calls attention to the fact that scientists in different biological disciplines varied considerably in their degree of acceptance of Darwin's theories. Mayr shows us that these differences were played out in four separate periods: 1859 to 1899, 1900 to 1915, 1916 to 1936, and 1937 to 1947. He thus enables us to understand fully why the synthesis was necessary and why Darwin's original theory--that evolutionary change is due to the combination of variation and selection--is as solid at the end of the twentieth century as it was in 1859.