Anthropology test 2 study questions: primate evolution and primatology, know how anthropologists place fossils into evolutionary order based on the dating techniques that determine age and the homologies we use to define species. Two methods: relative dating, absolute dating. Stratigraphy how the sediments of the earth are deposited over time. Radiometric techniques measuring loss of unstable radioactive isotopes. Early cenozoic primates in a tropical world: arboreal environment. Brain/body size ratio (increased cranial capacity, sexual dimorphism) Sociability (communication, language: be knowledgeable of the evolutionary tree for primates, particularly the branches leading to the human species, think about why we study primatology in anthropology. Studying primates helps us understand the origins of humans. We can observe living primates and note the similarities and differences between the primates and humans. Humans are most closely related to chimpanzees: common chimpanzee, bonobo. Shortened faces signs of sexual dimorphism, as do humans.