Chapter 9 focuses on the emergence of primates and early primate evolution. The chapter continues the discussion that began in the previous chapter with an overview of the ramifications for this evolution, the result of the demise of the dinosaur at the end of the Mesozoic era. The changes over time that led to the rise of primates from other mammalian forms are explained.

Following the introduction, the chapter examines major adaptive radiations of primate-like mammals beginning in the Paleocene (65.5 mya) that lead to the origin of 'true primates.' Early insectivores, arboreal and nocturnal, are today represented by modern primate forms. Other mammalian forms are discussed in the context of geological and climatic change is outlined. Models of primate origins are also discussed.

The next section covers anthropoid origins in the Old World and the New World. New World monkey origins are also considered.

The evolution of the Miocene hominids is considered next. The continued evolution of Old World anthropoids is explained in two branches: one leading to the modern Old World monkeys, the other, to modern hominoids, including apes and humans. Climatic conditions in the early and middle Miocene are explained in the contexts of how they served as a catalyst for environmental change, and in turn, in the diversity found in hominoid evolution. Fossil forms providing scientific evidence are discussed. Due to its evolutionary significance base upon skeletal evidence, special emphasis is placed in Proconsul, an African-dwelling genus. Other Miocene hominoids are also discussed.

The final section of the chapter includes a section discussing molecular dating, involving the use of genetic evidence from living hominoids. The method is used to enhance the interpretation of Miocene fossils.