Chapter One The Science of Biology

Responding to users' suggestions, the content of Chapter 1 has been reorganized, so that basic biological principles are presented before the scientific method, rather than after it. Considerable material has been added on the properties of life.

Chapter Two Evolution and Ecology

At the suggestion of users who like to begin with the larger concepts of ecology and evolution, the second edition has a new introductory chapter that presents the basics of evolution and ecology. It has a complete treatment of Darwin (6 pages), and an up-close examination of four cases of "evolution in action" (Galapagos finches, Hawaiian Drosophila, Lake Victoria cichlid fishes, and New Zealand alpine buttercups). The introduction to ecology introduces the concept of ecosystems and analyzes patterns of population growth.

Chapter Three The Chemistry of Life

This chapter has been reorganized to bring all the "origin of life" material together at the end of the chapter, rather than scattered throughout. The treatment of the origin of life has been updated to encompass current active research. A detailed 2-page examination of the "Mars rock" - controversial claims of past microbial life on a Mars meteorite - has been added. The chapter now concludes with a detailed examination of creationist objections to evolution.

Chapter Four Cells

This chapter now includes the treatment of membranes and transport that once appeared in the following chapter, so that all elements of cell structure and function are now taught together. Six process boxes are used to lay out the basic concepts of transport across cell membranes. A treatment of cell movement has been added.

Chapter Five Energy and Life

A treatment of the basics of thermodynamics now opens the chapter. Treatment of the light-dependent reactions of photosynthesis has been expanded to 4 pages, with a detailed look at the molecular anatomy of phosystems, and a step-by-step account of how a chloroplast's two photosystems act together to convert light to chemical energy. Process boxes make the overall architecture of glycolysis and the Krebs cycle much clearer and more approachable to students.

Chapter Six How Cells Divide

At the suggestion of many users, this new chapter gathers together mitosis and meiosis so that they can be taught together, and positions them immediately before Mendelian genetics, where meiosis provides a key explanation. A detailed treatment of "control of the cell cycle" has been added, followed by a 4-page examination of how cancer results from damage to these controls, and recent exciting progress in curing cancer. Mitosis and meiosis are compared, and the evolutionary consequences of sex discussed, in a new overview that ends the chapter.

Chapter Seven Foundations of Genetics

The treatment of phenotypic interactions has been expanded, and detailed coverage added of the chromosomal theory of inheritance and sex linkage. The presentation of human inherited disorders is now more extensive and detailed.

Chapter Eight How Genes Work

The treatment of classic experiments has been expanded to include Avery and Meselson & Stahl. Presentation of the Genetic Code has been simplified (see figure 8-13). A detailed treatment of mutation has been added, including its role in causing cancer.

Chapter Nine Gene Technology

Totally redone, this chapter carefully outlines the stages of a gene transfer experiment, and explains PCR and DNA fingerprinting. Up-to-date information on genome sequencing and the human genome project are provided. A new section has been added on cloning, with the most recent advances noted and potential ethical problems discussed.

Chapter Ten Evolution and Natural Selection

Reorganized, this chapter now starts with a consideration of the importance of genetic variation and how it affects the pace of evolution. Industrial melanism, the most famous case of evolution in action, is reexamined in light of new information.

Chapter Eleven How We Name Living Things

A new treatment of kingdoms and domains has been added (5 pages), which includes up-to-date information on the unexpected ubiquity of archaebacteria and the controversy over how to best classify them.

Chapter Twelve The First Single-Celled Creatures

A detailed comparison of bacteria to eukaryotes has been added, as well as a 2-page treatment of how animal viruses enter cells, featuring new information on the HIV life cycle. The controversy over prions and Prusiner's Nobel prize is examined in a new section that also considers viroids.

Chapter Thirteen Advent of the Eukaryotes

This chapter is reorganized, with general properties of eukaryotes presented first, including a section on the evolution of multicellularity. The protist phyla are regrouped into the most currently-accepted categories.

Chapter Fourteen Evolution of Multicellular Life

This chapter now begins with a consideration of complex multicellularity, and then gives a detailed look at the fungi.

Chapter Fifteen Evolution of the Plants

Little has been done to this chapter, except material has been added on the primitive vascular plants.

Chapter Sixteen Plant Form and Function

The "Living Plant" chapter has been reorganized, with hormones and plant reproduction moved to a new chapter.

Chapter Seventeen Plant Reproduction and Growth

This new chapter incorporates elements of the previous edition's "Living Plant" chapter, with little new material.

Chapter Eighteen Evolution of the animal Phyla

The chapter now opens with a 2-page discussion of general features of animals, rather than 2 paragraphs. A page discussing body cavities has been added, as well as 2 pages discussing the transition from protostome to deuterstome.

Chapter Nineteen History of the Vertebrates

The physiological adaptation section of this chapter has been moved to individual physiology chapters later in the text, and the treatment of mammals expanded.

Chapter Twenty How Humans Evolved

This chapter has been entirely redone, using considerable recent information to bring it up to date in a rapidly-developing field. Much of the early human family tree has been redrawn by recent fossil finds. The Out-of-Africa vs. Multiregional hypotheses are contrasted, an area of considerable current controversy.

Chapter Twenty One The Animal Body and How It Moves

This chapter now begins with a 4-page consideration of the animal body plan, focusing on four issues: radial vs. bilateral symmetry, solid body vs. body cavity, segmented vs. non-segmented bodies, and protostome vs. deuterostome embryos. Throughout, nonhuman vertebrates and other animals are emphasized as appropriate, rather than restricting the treatment to humans as in the past edition.

Chapter Twenty Two Circulation and Respiration

This chapter has been expanded by half, with extensive new coverage of nonhuman animals. It now opens with a 2-page discussion of the variety of animal circulation systems, followed by a 2-page discussion of the evolution of vertebrate circulatory systems. Later in the chapter, respiration is similarly introduced by 4 more pages on the diversity and evolution of animal respiratory systems. The discussion of lung cancer and smoking has been updated to reflect current knowledge of Rb and p53 tumor suppressors and their mutation by benzo (a) pyrene, a chemical in cigarette smoke.

Chapter Twenty Three The Path of Food Through the Animal Body

This chapter has been greatly expanded to better cover nonhuman animals. General discussions of animal digestive systems now precede vertebrate ones, and a 2-page treatment of variations in vertebrate digestive systems (ruminants, etc.) has been added. Two pages have been added on osmoregulatory organs in non-vertebrate animals, and four more on the evolution of the vertebrate kidney.

Chapter Twenty Four How the Animal Body Defends Itself

A 2-page treatment has been added on the evolution of the immune system, and a 4-page discussion of antibody diversity and clonal selection. The AIDS discussion is updated.

Chapter Twenty Five The Nervous System

This chapter now opens with a 2-page discussion of the evolution of animal nervous systems, and then moves to neurons and synapses. The treatment of the molecular basis of drug addiction has been greatly expanded. There is a new 2-page section on the evolution of the vertebrate brain, and one page devoted to the evolution of the eye.

Chapter Twenty Six Chemical Signaling Within the Animal Body

The role of nitric oxide signaling (for which this year's Nobel Prize in Medicine was awarded) has been added, as well as a discussion of molting hormones.

Chapter Twenty Seven Reproduction and Development

This chapter has been extensively reworked to better treat the breadth of animal approach to reproduction. It now begins with a 2-page overview of the different approaches animals take to reproduction, including many sorts of asexual and sexual systems. This is now followed by 4 pages treating the evolution of reproductive systems in the vertebrates.

Chapter Twenty Eight Ecosystems

A detailed look at El Nino weather systems has been added, as well as a detailed consideration of the high degree of diversity recently (and unexpectedly) discovered in the deep benthos.

Chapter Twenty Nine Living in Ecosystems

The section on the theory of population growth has been redone and expanded, and is used to discuss variations in life history strategies of natural populations. The section on competition and resource partitioning is new, reflecting recent discoveries. A 2-page treatment of predator-prey cycles has been added, the section on biodiversity rewritten to reflect new ideas being discussed by researchers, and a new section on island biogeography added.

Chapter Thirty Planet Under Stress

Information for this chapter has been updated to reflect changes in the three years since the last edition.