Hybrid zones--geographical areas in which the hybrids of two races are found--have attracted the attention of evolutionary biologists for many years, both because they are windows on the evolutionary process and because the patterns of animals and plant variation seen in hybrid zones do notfit the traditional classification schemes of taxonomists. Hybrid zones provide insights into the nature of the species, the way barriers to gene exchange function, the genetic basis of those barriers, the dynamics of the speciation process. Hybrid Zones and the Evolutionary Process synthesizes theextensive research literature in this field and points to new directions in research. It will be read with interest by evolutionary biologists, geneticists, and biogeographers.

Michael L. Arnold offers an exploration of the evolutionary process of natural hybridisation, and presents data from various sources that support the paradigm of natural hybridisation as an important evolutionary process.

The nature of populations, races, subspecies, and species. Genetic basis of isolation. Origin of isolation - theoretical. Origin of isolation - experimental. The nature of the speciation process.

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.

This visually appealing book recounts the history of molecular ecology and evolution as seen through the personal lens of one of its most prolific practitioners, who has studied a panorama of creatures ranging from corals, sponges, and other invertebrates to a wide variety of vertebrate animals including numerous birds, mammals, herps, and fishes. The sketches are of two types: evocative drawings of the animals themselves, and more than 230 written abstracts summarizing the author's eclectic research on ecological-genetic topics spanning the microevolutionary to macroevolutionary. With the abstracts arranged by organismal group and placed in chronological order, the chapters in this book lead readers on a fascinating historical journey into the realm of molecular genetics as applied across the past four decades to intriguing questions in ecology, evolution, animal behavior, and natural history. - Encapsulates salient genetic findings on a diverse array of creatures in nature - Recounts the history of technological and conceptual developments in ecological genetics - Includes approximately 80 beautiful line drawings of the animals themselves - Provides context by preceding each abstract with an anecdote or historical backdrop - Concludes each abstract with an addendum that further contextualizes the research findings - Written by a world-leading authority in molecular ecology and evolution

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 for AP® courses covers the scope and sequence requirements of a typical two-semester Advanced Placement® biology course. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology for AP® Courses was designed to meet and exceed the requirements of the College Board’s AP® Biology framework while allowing significant flexibility for instructors. Each section of the book includes an introduction based on the AP® curriculum and includes rich features that engage students in scientific practice and AP® test preparation; it also highlights careers and research opportunities in biological sciences.