Vertebrate Life explores how the anatomy, physiology, ecology, and behaviour of animals interact to produce organisms that function effectively in their environments, and how lineages of organisms change through evolutionary time. It looks at the evolution, diversity, and classification of vertebrates. It considers chondrichthyes, osteichthyes as well as teteapods. Ectothermy is examined as an example of a low-energy approach to life. Other vertebrates considered are turtles, lepidosaurs, crocodylians, and extant birds and mammals.
Book
F. Harvey Pough, William E. Bemis, Betty Mcguire, and Christine M. Janis
Chapter
Diversity, Classification, and Evolution of Vertebrates
This chapter explores the diversity, classification, and evolution of vertebrates. It highlights how evolution is central to biology since its overarching principles allow further understanding of how living organisms operate and organize their diversity. Phylogenetic systematics produces branching evolutionary diagrams or phylogenetic trees which show changes in characteristics. The chapter then covers the genetic mechanisms and environmental events that have shaped the evolution and biology of vertebrates. It looks into Earth's history in relation to the evolution of vertebrates and Earth's pattern of fragmentation and coalescence which isolated and renewed contacts of major groups of vertebrates, and which then produced the biogeographic distributions of vertebrates.
Chapter
Ectothermy and Endothermy
Two Ways of Regulating Body Temperature
This chapter looks at the concept of ectothermy and endothermy in relation to regulating body temperature. It highlights the importance of controlling body temperature. Vertebrates employ a variety of behavioral and physiological mechanisms to control body temperature. The evolution of endothermy was a major event in vertebrate evolution, especially within the sauropsid and synapsid lineages. Moreover, the processes of endothermy and ectothermy are not mutually exclusive since many tetrapods combine elements of both modes. The consequences of ectothermy and endothermy shaped the lifestyles of different vertebrates and this informs some important consequences of these lifestyles in the context of ecosystems.
Chapter
Primate Evolution and the Emergence of Humans
This chapter discusses the relationship between primate evolution and the emergence of humans. Molecular techniques show that chimpanzees and bonobos are the closest extant relatives to humans. Humans and their fossil relatives belong to a tribe within Hominidae called Hominini. In comparison to other hominids, humans exhibit three major derived characteristics which are bipedality, a greatly enlarged brain, and the ability for speech and language. The chapter then details the effects of Homo sapiens, the only surviving hominin species, on other vertebrates and the course of life on Earth. It acknowledges humans as superpredators that kill large animals that otherwise have no natural predators as adults.
Chapter
Living in Water
This chapter looks at vertebrates which live successfully in water. A vertebrate must adjust its buoyancy to remain at a specific depth and must force its way through a dense medium to pursue prey or escape predators. Thus, aquatic vertebrates have evolved solutions to the physical challenges of life in water. The chapter primarily focuses on fishes and lissamphibians to consider sensory systems in water and on land. The evolutionary diversification of teleosts resulted in an enormous array of sizes and ways of life in freshwater and marine environments. The chapter details the process of osmoregulation in different environments.
Book
F. Harvey Pough, Robin M. Andrews, Martha L. Crump, Alan H. Savitzky, Kentwood D. Wells, and Matthew C. Brandley
Herpetology explains why amphibians and reptiles, which are distantly related evolutionary lineages, are grouped in the discipline known as herpetology, and describes the position of amphibians and reptiles within the evolution of vertebrates. Part I asks, what are amphibians and reptiles? It considers the origins, systematics, and diversity of amphibians and reptiles. Part II looks at the way that amphibians and reptiles actually function. It looks at reproduction and feeding. The third part questions what amphibians and reptiles do? It looks at how they communicate, mate, and at their diets. The last part looks to the future, considering the conservation of amphibians and reptiles and their prospects for survival.
Chapter
Vertebrate development I: life cycles and experimental techniques
This chapter explores similarities and differences in the development of frogs, birds, fish, and mammals. It also looks into experimental approaches which investigate vertebrate development using Xenopus, zebrafish, chick, and mouse as models. The chapter refers here to transgenic techniques which are used to produce mutations with specific genes as an example. Additionally, the chapter notes how all vertebrates have a similar basic body plan with defining structures such as the spinal cord and skull. It shows the similarity between a mouse and a human in terms of early development. The chapter also links approaches used in investigating human embryonic development. Techniques for interfering with development can be broadly divided between experimental embryological techniques and genetics-based techniques.
Chapter
Cardiovascular systems
This chapter discusses the cardiovascular systems of animals. Most invertebrates have an open circulatory system, although decapod crustaceans and some species of non-cephalopod molluscs have an incompletely closed system. Vertebrates have a closed circulatory system: all blood vessels are lined with endothelium. In water-breathing invertebrates, the ventricle propels the blood around the body and then through the gills for gas-exchange. The chapter then looks at the structure and function of blood vessels. In vertebrates, blood vessels consist of three layers: tunica intima, tunica media, and tunica externa. The rate of flow of a fluid through a long straight rigid tube is described by Poiseuille's equation. The major factor affecting the resistance to blood flow is the radius of a blood vessel.
Chapter
Neurons, nerves and nervous systems
This chapter evaluates the nervous systems in animals. All animals except Placozoa and Porifera (sponges) have a well-defined nervous system, which is the main means of communication between the animal and the outside world. Animals with bilateral symmetry have a central and a peripheral nervous system. The central nervous system (CNS) in invertebrates is organized in ganglia close to sensory structures, while the CNS in vertebrates consists of the brain and the spinal cord. The chapter then looks at the ionic basis of electrical activity in neurons, before considering how neurons communicate with each other. Signal transmission between neurons takes place at synapses, which are of two types: electrical synapses and chemical synapses.
