This book summarizes the key adaptations enabling extremophile fishes to survive under harsh environmental conditions. It reviews the most recent research on acidic, Antarctic, cave, desert, hypersaline, hypoxic, temporary, and fast-flowing habitats, as well as naturally and anthropogenically toxic waters, while pointing out generalities that are evident across different study systems. Knowledge of the different adaptations that allow fish to cope with stressful environmental conditions furthers our understanding of basic physiological, ecological, and evolutionary principles. In several cases, evidence is provided for how the adaptation to extreme environments promotes the emergence of new species. Furthermore, a link is made to conservation biology, and how human activities have exacerbated existing extreme environments and created new ones. The book concludes with a discussion of major open questions in our understanding of the ecology and evolution of life in extreme environments.

The history of biology is populated by numerous model species or organisms. But few vertebrate groups have aided evolutionary and ecological research more than the live-bearing fishes of the family Poeciliidae. Found throughout tropical and subtropical waters, poeciliids exhibit a fascinating variety of reproductive specializations, including viviparity, matrotrophy, unisexual reproduction, and alternative mating strategies, making them ideal models for research on patterns and processes in ecology, behavior, and evolution. Ecology and Evolution of Poeciliid Fishes is a much-needed overview of the scientific potential and understanding of these live-bearing fishes. Chapters by leading researchers take up a wide range of topics, including the evolution of unisexual reproduction, life in extreme environments, life-history evolution, and genetics. Designed to provide a single and highly approachable reference, Ecology and Evolution of Poeciliid Fishes will appeal to students and specialists interested in all aspects of evolutionary ecology.

In most habitats, adaptations are the single most obvious aspects of an organism's phenotype. However, the most obvious feature of many subterranean animals are losses, not adaptations. Even Darwin saw subterranean animals as degenerates: examples of eyelessness and loss of structure in general. For him, the explanation was a straightforward Lamarc

When Charles Darwin first proposed Sexual Selection Theory, he suggested two mechanisms: competition among males and choice by females. Although their importance is long established and extremely well understood, their mirror images have remained largely underappreciated; males also choose, and females also compete. The combination of male mate choice (MMC) and female competition (FC) may be one of the most overlooked yet important and intriguing phenomena in modern sexual selection theory. This novel text reviews our current understanding of MMC and FC, highlighting the important connections between them. It places both concepts in the context of related fields such as female choice, mating systems, and sexual selection theory more broadly. A truly holistic approach is provided which takes all the relevant elements into consideration, especially the relative roles of MMC and FC, female ornamentation, their evolutionary consequences, and their genetic basis. Considering male mate choice and female competition in this way as effectively two sides of the same coin creates a powerful paradigm for a more complete understanding of sexual selection. Male Choice, Female Competition, and Female Ornaments in Sexual Selection will be suitable for both graduate students and researchers interested in sexual selection from an evolutionary, psychological, and anthropological perspective. It will also appeal to a broader audience of behavioural ecologists and evolutionary psychologists.

This book provides fascinating insights into the development and genetics of evolutionary processes on the basis of animals living in the dark, such as the Astyanax cave fish. Biologically functionless traits show high variability, which results from neutral deleterious mutations no longer being eliminated by natural selection, which normally acts to preserve functional capability. These negative mutations accumulate until the traits they are responsible for become rudimentary or even lost. The random genetic basis of regressive evolution is in accordance with Nei’s Neutral Theory of Molecular Evolution, which applies to the molecular level. Such processes are particularly conspicuous in species living in constant darkness, where, for example in Astyanax, all traits depending on the exposure to light, like eyes, pigmentation, visually triggered aggressive behaviour, negative phototaxis, and several peripheral outcomes of circadian rhythmicity, are useless and diminish. In compensation constructive traits like taste, olfaction or the lateral line senses are improved by selection and do not show variability. Regressive and constructive traits inherit independently, proving that the rudimentation process is not driven by pleiotropic linkage between them. All these traits are subject to mosaic evolution and exhibit unproportional epistatic gene effects, which play an important role in evolutionary adaptation and improvement. Offering valuable evolutionary insights and supplemented by a wealth of illustrations, this book will appeal to evolutionary and developmental biologists alike.