ABSTRACT
Chapter 12 categorizes the 4.5-billion-year history of the Earth into a few major ideas. The first section reviews the theory behind radioactive dating and the definition of a fossil. The second reviews the history of life and categorizes the major domains and kingdoms of life. The third reviews how Earth’s atmosphere formed and has students recall the basic chemical formulas for photosynthesis and respiration. The fourth breaks down the 600-million-year-old geologic history of life intro three major periods: the Age of Plants and Marine Invertebrates (Paleozoic), the Age of Reptiles (Mesozoic), and the Age of Mammals (Cenozoic). The major organisms to evolve during each period are described, including a section on the evolution of humans.
