A readily comprehensible guide for biologists, field taxonomists and interested laymen to one of the oldest problems in biology: the species problem. Written by a geneticist with extensive experience in field taxonomy, this practical book provides the sound scientific background to the problems arising with classifying organisms according to species. It covers the main current theories of specification and gives a number of examples that cannot be explained by any single theory alone.

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.

There is long-standing disagreement among systematists about how to divide biodiversity into species. Over twenty different species concepts are used to group organisms, according to criteria as diverse as morphological or molecular similarity, interbreeding and genealogical relationships. This, combined with the implications of evolutionary biology, raises the worry that either there is no single kind of species, or that species are not real. This book surveys the history of thinking about species from Aristotle to modern systematics in order to understand the origin of the problem, and advocates a solution based on the idea of the division of conceptual labor, whereby species concepts function in different ways - theoretically and operationally. It also considers related topics such as individuality and the metaphysics of evolution, and how scientific terms get their meaning. This important addition to the current debate will be essential for philosophers and historians of science, and for biologists.

Nineteenth-century scientist David Starr Jordan built one of the most important fish specimen collections ever seen, until the 1906 San Francisco earthquake shattered his life's work.

This open access book offers the first comprehensive account of the pan-genome concept and its manifold implications. The realization that the genetic repertoire of a biological species always encompasses more than the genome of each individual is one of the earliest examples of big data in biology that opened biology to the unbounded. The study of genetic variation observed within a species challenges existing views and has profound consequences for our understanding of the fundamental mechanisms underpinning bacterial biology and evolution. The underlying rationale extends well beyond the initial prokaryotic focus to all kingdoms of life and evolves into similar concepts for metagenomes, phenomes and epigenomes. The book’s respective chapters address a range of topics, from the serendipitous emergence of the pan-genome concept and its impacts on the fields of microbiology, vaccinology and antimicrobial resistance, to the study of microbial communities, bioinformatic applications and mathematical models that tie in with complex systems and economic theory. Given its scope, the book will appeal to a broad readership interested in population dynamics, evolutionary biology and genomics.

Over the last two decades, the study of speciation has expanded from a modest backwater of evolutionary biology into a large and vigorous discipline. Speciation is designed to provide a unified, critical and up-to-date overview of the field. Aimed at professional biologists, graduate students and advanced undergraduates, it covers both plants and animals and deals with all relevant areas of research, including biogeography, field work, systematics, theory, and genetic and molecular studies. It gives special emphasis to topics that are either controversial or the subject of active research, including sympatric speciation, reinforcement, the role of hybridization in speciation, the search for genes causing reproductive isolation, and mounting evidence for the role of natural and sexual selection in the origin of species.

In December 2004, the National Academy of Sciences sponsored a colloquium on "Systematics and the Origin of Species" to celebrate Ernst Mayr's 100th anniversary and to explore current knowledge concerning the origin of species. In 1942, Ernst Mayr, one of the twentieth century's greatest scientists, published Systematics and the Origin of Species, a seminal book of the modern theory of evolution, where he advanced the significance of population variation in the understanding of evolutionary process and the origin of new species. Mayr formulated the transition from Linnaeus's static species concept to the dynamic species concept of the modern theory of evolution and emphasized the species as a community of populations, the role of reproductive isolation, and the ecological interactions between species. In addition to a preceding essay by Edward O. Wilson, this book includes the 16 papers presented by distinguished evolutionists at the colloquium. The papers are organized into sections covering the origins of species barriers, the processes of species divergence, the nature of species, the meaning of "species," and genomic approaches for understanding diversity and speciation.