Life : The Science of Biology

1. An Evolutionary Framework for Biology

A new section shows how experimental and comparative approaches are used by biologists to test hypotheses.

PART ONE THE CELL

2. Life and Chemistry: Small Molecules

The description of cell chemistry (small molecules) now focuses more on applications to biology and less on nomenclature.

3. Life and Chemistry: Large Molecules

Rewritten to feature the ideas for the origin and continuity of life and experimental evidence supporting these ideas. There is also considerable emphasis on the role of molecular shapes in biological function.

4. Cells: The Basic Units of Life

The chapter on cell biology is now framed in ideas on the origin and evolution of cells. It also has new material on how cell organelles are isolated and studied.

5. Cellular Membranes

Features new material on important discoveries of lipid rafts, cytoskeletal interactions, and the structure and function of a membrane ion channel for potassium.

6. Energy, Enzymes, and Metabolism

The discussion of thermodynamics has been reduced and is more focused on biological applications. The description of how enzymes work features the chemistry at the active site.

7. Cellular Pathways That Harvest Chemical Energy

Art describing complex biochemical pathways has been streamlined for clarity and there are better overviews to keep the reader focused on the big picture.

8. Photosynthesis: Energy from the Sun

Art has been streamlined for clarity and the material on C3 and C4 plants is more focused in basic concepts and less on details.

ESSAY: What is science?

PART TWO INFORMATION AND HEREDITY

9. Chromosomes, the Cell Cycle, and Cell Division

Features new material on the control of cell division at the restriction point and its relevance to cancer, and on how chromosomes stick together, plus a more focused discussion of cell death.

10. Genetics: Mendel and Beyond

After carefully developing Mendel's principles, the chapter focuses on human applications. There is a new discussion of the important interactions of heredity and environment in producing complex characteristics.

11. DNA and Its Role in Heredity

The subject of telomeres, the ends of DNA molecules, has been moved to this chapter, which also features the applications of the principles of DNA replication in PCR (polymerase chain reaction) and DNA sequencing.

12. From DNA to Protein: Genotype to Phenotype

Features experimental evidence for such concepts as genes and proteins and the genetic code, as well as a clear description of the nature of mutations.

13. The Genetics of Viruses and Prokaryotes

This chapter on microrganisms and viruses emphasizes gene control in these systems, as well as new discoveries in the merging field of microbial genomics.

14. The Eukaryotic Genome and Its Expression

Includes recent discoveries on sequenced genomes, ranging from the yeast to fruit fly to worm to the puffer fish and rice. Also describes new gene control mechanisms such as RNA editing.

15. Cell Signaling and Communication

New in the Sixth Edition, this chapter includes new material on signaling in bacteria, and is more clearly focused on such aspects as amplification and second messengers.

16. Recombinant DNA and Biotechnology

Updated to include new methods, such as RNA interference (RNAi) and the two-hybrid system, and new results, such as breeding of salt-tolerant crops. There is a more focused discussion of these applications, as well as their implications and public concerns.

17. Molecular Biology and Medicine

A focused yet comprehensive overview of the molecular genetics of humans, including new discoveries from the human genome project and the emerging field of proteomics.

18. Natural Defenses against Disease

Includes new and clearer art to describe complex immune system phenomena, and more focused discussions of nonspecific defenses and AIDS.

ESSAY: What are the ethical and philosophical issues surrounding genetically modified foods?

PART THREE DEVELOPMENT

Part Three is new in this edition. It deals with the fascinating processes of development from fertilized egg to adult organism.

19. Differential Gene Expression in Development

Chapter 19 on the genetic principles that govern development is a bridge between Parts Two and Three. It applies the molecular concepts outlined in Chapters 12, 14, and 15 to development.

20. Animal Development: From Genes to Organism

This chapter has been updated with new information on the molecular mechanisms of determination that are initiated in the fertilized egg and create the basic body plan of the embryo.

NEW 21. Development and Evolutionary Change

This NEW chapter discusses how the rapidly developing science of evolutionary developmental biology, which unites developmental biology, ecology, and genetics, is providing new insights into how new body structures appear during evolution and how the development of organisms can be modified without making the resulting adult organisms nonfunctional.

ESSAY: What are the moral issues surrounding stem cell therapy?

PART FOUR EVOLUTIONARY PROCESSES

22. The History of Life on Earth

The major features of the evolution of the diversity of life over several billion years
are described to provide a background for the discussion of evolutionary processes that are discussed in subsequent chapters. The discussion integrates information on Earth's geological history with patterns in life's evolution.

23. The Mechanisms of Evolution

This chapter discusses the agents of evolution, shows why natural selection is the only agent that can adapt organisms to their environments, and presents experiments that show how scientists study biological evolution.

24. Species and Their Formation

This chapter defines what species are, describes how new species arise, discusses the factors that reinforce reproductive isolation between newly formed species, and outlines the conditions that lead to evolutionary radiations.

25. Reconstructing and Using Phylogenies

How phylogenies are reconstructed, and how knowledge about the evolutionary relationships among organisms is used to help us understand other biological processes, are succinctly described in this chapter.

26. Molecular and Genomic Evolution

This substantially revised chapter discusses the evolution of macromolecules and genomes, how proteins acquire new functions, and how scientists use information about molecular and genomic evolution to solve other biological problems.

ESSAY: How has Darwin's theory of natural selection transformed our view of humanity's place in the universe?

PART FIVE THE EVOLUTION OF DIVERSITY

27. Bacteria and Archaea: The Prokaryotic Domains

Emphasizes evolution in the prokaryotes and focuses on a few well-established clades. The treatment of archaea has been updated and expanded, including a discussion of lateral gene transfer and a brief introduction to biofilms.

28. Protists and the Dawn of the Eukarya

As in the previous edition, this evolutionarily-oriented chapter focuses on a number of protist clades and is based on the best current evidence. Our reviewers have helped us choose among competing viewpoints of current researchers.

29. Plants without Seeds: From Sea to Land

This chapter includes an improved discussion of alternation of generations. The evolutionary relationships among the ferns have been clarified.

30. The Evolution of Seed Plants

The emphasis on evolution continues through the chapter on seed plants. The treatment of groups that are neither monocots nor eudicots has been upgraded and clarified to reflect current views of phylogeny.

31. Fungi: Recyclers, Pathogens, Parasites, and Plant Partners

The definition and classification of fungi used here are based on phylogenetic evidence. The life cycles have been redrawn for improved clarity.

32. Animal Origins and the Evolution of Body Plans

This chapter presents the evidence that shows that all animals, with the possible exception of sponges, are descendants of a common ancestor. It reviews the types of evidence used to infer evolutionary relationships among the lineages of animals, and gives an overview of the phyla of simple diploblasic animals and the lophotrochozoans, one of two major lineages of protostomate animals.

33. Ecdysozoans: The Molting Animals

This chapter reviews the impressive diversity of the ecdysozoans, the protostomate lineage that includes the animals that molt their exoskeletons several times during their development to adulthood. It discusses how having an exoskeleton has influenced the evolution of ecdysozoans.

34. Deuterostomate Animals

This chapter describes the deuterostomate phyla, paying particular attention to human evolution, and provides an overview of some of the major themes in the evolution of animals on Earth.

ESSAY: What is our duty to nature?

PART SIX THE BIOLOGY OF FLOWERING PLANTS

35. The Plant Body

We include a thorough introduction to the anatomy of angiosperms, with close attention to the meristems that give rise to the primary and secondary plant bodies.

36. Transport in Plants

In this edition, we paid special attention to the question of level, removing certain material more appropriate to a plant physiology course but adding interesting new material such as an experiment figure demonstrating the effect of potassium ions on flow rate in the xylem.

37. Plant Nutrition

This chapter on plant nutrition includes an increased emphasis on the economic importance of parasitic plants and an enhanced treatment of the role of chemical weathering in soil formation.

38. Regulation of Plant Growth

This presentation of the hormones and photoreceptors that regulate plant growth and development includes an updated treatment of auxin carriers and polar auxin transport. The coverage of brassinosteroids has been updated to link more firmly to the photomorphogenesis material that follows, and the treatment of blue-light receptors is fully current.

39. Reproduction in Flowering Plants

We clarified, sharpened, and updated the treatments of the genes determining flower structure and of the role of the synergids in attracting pollen tubes. There is a new figure and text on the photoperiodic regulation of flowering, based on the genes constituting the biological clock and on the interaction of proteins and light absorption by phytochrome and cryptochrome.

40. Plant Responses to Environmental Challenges

This chapter on plant responses to environmental challenges, both by other organisms and by physical factors, reflects current interests in plant biology. It includes new material on RNA silencing and its role in plant defenses against viruses.

ESSAY: How should we manage fire in the forest?

PART SEVEN THE BIOLOGY OF ANIMALS

41. Physiology, Homeostasis, and Temperature Regulation

Additions to this chapter include the use of energy budgets to integrate the effects of allphysiological, anatomical, and behavioral adaptations that influence the thermal biology of a species. Another new feature is a treatment of the relationship between body size and metabolism.

42. Animal Hormones

An important addition to the hormones chapter is a description of a principle tool in hormone research, the radioimmunoassay. Coverage of the hormonal regulation of calcium metabolism has been expanded to include the regulation of blood phosphate levels.

43. Animal Reproduction

Additions include discussions of testes size in mammals and the evolutionary consequences of sperm competition. The discussions of human reproductive systems and both contraceptive and assisted reproductive technologies have been improved.

44. Neurons and Nervous Systems

The presentation of the generation and conduction of action potentials has been improved along with a series of excellent illustrations.

45. Sensory Systems

The discussions of sensory transduction mechanisms have been updated and there is new treatment of recent research on the vomeronasal organ that plays an important role in the sensing of mammalian pheromones.

46. The Mammalian Nervous System: Structure and Higher Functions

This unique chapter treats very interesting higher-level functions of the mammalian nervous system. Coverages of learning and memory, sleep, and visual processing have been updated.

47. Effectors: Making Animals Move

The description of the molecular mechanism of skeletal muscle contraction has been expanded by inclusion of the role of the unique protein titin that prevents the muscle fibers from being overstretched.

48. Gas Exchange in Animals

New coverage in this chapter includes mechanisms of ventilation in insects and the function of lung surfactants in mammals. A strong point of this chapter remains the comparative mechanisms of gas exchange in animals.

49. Circulatory Systems

A new discussion of how the hearts of reptiles are not "imperfect" mammalian hearts but are uniquely suited to their physiology is included. A new hypothesis about the exchange of carbon dioxide between tissues and the blood is presented. A discussion of heart disease has been included.

50. Nutrition, Digestion, and Absorption

Exciting recent information on genes involved in the regulation of food intake and body mass is discussed. Coverage of the hormonal control of fuel metabolism has been revised and remains a strong feature of the chapter.

51. Salt and Water Balance and Nitrogen Excretion

The coverage of the mechanisms of urine production and concentration in the mammalian kidney has been revised and improved. Coverage of the role of the kidney in acid base balance has been added.

52. Animal Behavior

This chapter continues to cover the spectrum from classical ethology to current studies of the molecular genetics of behavior. Recent research on the molecular mechanisms of reproductive behavior in Drosophila and the molecular mechanisms of the circadian clock are presented.

ESSAY: What are the ethical issues surrounding medical treatment?

PART EIGHT ECOLOGY AND BIOGEOGRAPHY

53. Behavioral Ecology

Many features of populations and ecological communities are the result of the myriad decisions individuals make about where to live, what to eat, and with whom to associate. How individuals make these important decisions, and the consequences of how they make them, are described in this chapter with some new examples.

54. Population Ecology

The discussion of the structure and dynamics of populations has been changed in this heavily revised chapter to show how ecology can be used to help us provide answers to major questions asked by both ecologists and the general public. Why are some species common whereas others are rare? Why do some populations fluctuate much more than others? Why do species' ranges vary so much? How can we use our understanding of population dynamics to manage species of interest?

55. Community Ecology

This revised chapter integrates community and ecosystem ecology to illustrate how interactions among species in ecological communities and environmental disturbances influence the species-richness of communities and affect the productivity and stability of ecosystems. New material is presented to show how disturbances influence the structure and dynamics
of ecological systems.

56. Biogeography

The distribution of terrestrial biomes is illustrated in this chapter with a combination of photographs and graphs that show temporal patterns of temperature, precipitation, and the activities of organisms in them. The boundaries between marine biomes and how they are determined by abrupt changes in the temperature and salinity of ocean waters are also described.

57. Conservation Biology

This chapter has been revised to illustrate the ways conservation biologists use information from ecology, population genetics, biogeography, and evolutionary biology to determine the causes of endangerment and extinction of species, conduct new experiments, and then use that information to help preserve the biological diversity of life on Earth.

NEW 58. Earth System Science

This NEW chapter covers a rapidly developing field of study that looks at the whole Earth as a system. The chapter describes how life has altered the chemistry and climate of Earth, making it a very unusual planet. The chapter also describes the great biogeochemical cycles that control how the elements of which life is composed move among the oceans, atmosphere, freshwaters, and land. The chapter ends with a brief discussion of possible future visions of interactions of humans with Earth's systems.

ESSAY: What are the economics of sustainable management of ecosystems?