The previous three editions of <b><i>BIOLOGY</b></i>, written by <b>Dr. Rob Brooker, Dr. Eric Widmaier, Dr. Linda Graham, and Dr. Peter Stiling</b>, have reached thousands of students and provided them with an outstanding view of the biological world. Now, the fourth edition has gotten even better! The author team is dedicated to producing the most engaging and current text that is available for undergraduate students who are majoring in biology. The authors want students to be inspired by the field of biology and become critical thinkers. They understand the goal of a professor is to prepare students for future course work, lab experiences, and careers in the sciences. Building on the successes of the previous editions, the fourth edition reflects a focus on core competencies and provides a more learner-centered approach. The strength of an engaging and current text is improved with the addition of new pedagogical features that help develop and strengthen critical thinking skills.