This Immersion Unit provides a coherent series of lessons designed to guide students in developing deep conceptual understanding that is aligned with the standards, key science concepts, and essential features of classroom inquiry (as defined by the National Science Education Standards). The Unit's overarching concepts are:- Naturally occurring variations of traits in a population are influenced by genetic and environmental factors and evolve over generations by selective processes.- Science knowledge advances through inquiry.Unit Supporting Concepts:- The variation of organisms within a species increases the likelihood that at least some members of the species will survive under changed environmental conditions.- Individual organisms with certain traits are more likely than others to survive and have offspring. Changes in environmental conditions can affect the survival of individual organisms and entire species.- Some variation in heritable characteristics exists within every species. One of these characteristics gives individuals an advantage over others in surviving and reproducing, and the advantaged offspring, in turn,are more likely than others to survive and reproduce.- New varieties of cultivated plants and domestic animals have resulted from selective breeding for particular traits.- Scientists differ greatly in whatphenomena they study and how they go about their work. Although there is nofixed set of steps that all scientists follow, scientific investigations usually involve the collection of relevant evidence, the use of logical reasoning, and the application of imagination in devising hypotheses and explanations to make sense of the collected evidence.- Important contributions to the advancement of science, mathematics, and technology have been made by different kinds of people, in different cultures, at different times.In Immersion Units, students learn academic content by working like scientists: making observations, asking questions, doing further investigations to explore and explain natural phenomena, and communicating results based on evidence. Immersion Units are intended to support teachers in building a learning culture in their classrooms to sustain studentsĺŐ enthusiasm for engaging in scientific habits of thinking while learning rigorous science content.The first step of this unit engages students in developing a class criteria for effective record-keeping in science by guiding an inquiry into scientists' notebooks.The unit includes very complete implementation instructions (Teacher's Guide pages), student pages, and formative and summative assessments.Students investigate:- how variation within a population is influenced by environmental factors- how environmental factors influence reproductive success in a populationThis unit was developed through the large Math and Science Partnership project called System-wide Change for All Learners and Educators (SCALE), involving a collaboration among Los Angeles School District educators, California State University science and education faculty, and UW-Madison SCALE staff.