"Evolutionary biology has changed dramatically during the 15 years we have worked on Evolutionary Analysis. As one measure of this change, consider that when the first edition went to press, the genomes of just five cellular organisms had been sequenced: three bacteria, one archaean, and one eukaryote. As the fifth edition goes to press, Erica Bree Rosenblum and colleagues reported in the Proceedings of the National Academy of Sciences (110: 9385–9390) that they had sequenced the genomes of 29 strains of a single species, the chytrid fungus Batrachochytrium dendrobatidis. This work was part of an effort to unravel the evolutionary history of an emerging pathogen that has decimated amphibian populations around the world and driven some species to extinction. The avalanche of sequence data has allowed evolutionary biologists to answer long-standing questions with greatly increased depth and clarity. In Chapter 20, Human Evolution, for example, we discuss a recent analysis of differences among genomic regions in the evolutionary relationships among humans, chimpanzees, and gorillas. For some questions, the answers have changed completely. In the fourth edition we noted that available sequence data provided no support for the hypothesis that modern humans and Neandertals interbred. But in the fifth edition we describe genomic analyses suggesting that the two lineages interbred after all.
Evolutionary Analysis provides an entry to this dynamic field of study for undergraduates majoring in the life sciences. We assume that readers have completed much or all of their introductory coursework and are beginning to explore in more detail areas of biology relevant to their personal and professional lives. Therefore, throughout the book we attempt to show the relevance of evolution to all of biology and to real-world problems.
Since the first edition, our primary goal has been to encourage readers to think like scientists. We present evolutionary biology not as a collection of facts but as an ongoing research effort. When exploring an issue, we begin with questions. Why are untreated HIV infections typically fatal? Why do purebred Florida panthers show such poor health, and what can be done to save their dwindling population? Why do mutation rates decrease with genome size among some kinds of organisms, but increase with genome size among others? We use such questions to engage students’ curiosity and to motivate discussions of background information and theory. These discussions enable us to frame alternative hypotheses, consider how they can be tested, and make predictions. We then present and analyze data, consider its implications, and highlight new questions for future research. The analytical and technical skills readers learn from this approach are broadly applicable, and will stay with them long after the details of particular examples have faded."
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