Biology 2e is designed to cover the scope and sequence requirements of a typical two-semester biology course for science majors. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology includes rich features that engage students in scientific inquiry, highlight careers in the biological sciences, and offer everyday applications. The book also includes various types of practice and homework questions that help students understand—and apply—key concepts. The 2nd edition has been revised to incorporate clearer, more current, and more dynamic explanations, while maintaining the same organization as the first edition. Art and illustrations have been substantially improved, and the textbook features additional assessments and related resources.

By the end of this section, you will be able to do the following:

Define species and describe how scientists identify species as different
Describe genetic variables that lead to speciation
Identify prezygotic and postzygotic reproductive barriers
Explain allopatric and sympatric speciation
Describe adaptive radiation

In some cities, especially large cities such as Los Angeles or Mexico City, visible air pollution is a major problem, both for human health and the environment. A variety of sources contribute to air pollution, but personal vehicles account for one of the main sources. Though each car has relatively low emissions when compared to vehicles of the 1970s, there are so many more cars on the road now that their emissions play a large role in overall pollution. In this activity, students think about alternate ways to power a vehicle to reduce emissions. Student teams design an eco-friendly car using the engineering design process, and make a presentation to showcase their product.

Learn about the principle of dominance as you watch animations showing Mendel's experiments with pea plants. Find out what happened when he crossed plants that produced green seeds with those that produced yellow seeds.

Students investigate different forms of hybrid engines as well as briefly conclude a look at the different forms of potential energy, which concludes the Research and Revise step of the legacy cycle. Students are introduced to basic circuit schematics and apply their understanding of the difference between series and parallel circuits to current research on hybrid cars.

Students gain perspective on the intended purpose of hydraulic accumulators and why they might be the next best innovation for hybrid passenger vehicles. They learn about how hydraulic accumulators and hydraulic systems function, specifically how they conserve energy by capturing braking energy usually lost as heat. Students are given the engineering challenge to create small-scale models from which their testing results could be generalized to large-scale latex tubing for a hydraulic accumulator. After watching a video clip of an engineer talking about his lab-based model to test the feasibility of using an elastomer as an energy accumulator, they brainstorm ideas about how latex can be used in a hydraulic system and how they could test the strength of latex for use in a hydraulic accumulator. The concepts of kinetic energy and energy density are briefly discussed.

Students learn more about magnetism, and how magnetism and electricity are related in electromagnets. They learn the fundamentals about how simple electric motors and electromagnets work. Students also learn about hybrid gasoline-electric cars and their advantages over conventional gasoline-only-powered cars.