ISS 220 Lecture Notes - Lecture 6: Knuckle-Walking, Thumb, Color Vision
19 Oct 2016
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Document Summary
Evolution of humans can be understood by comparing to the evolution of about 230 nonhuman primates. Monkeys still exist because they hold an evolutionary advantage in some habitats still. Primates are analogies for understanding human evolution. Longer gestation period, learned behavior, social groups, diurnal. Specialized limbs and locomotion, no dietary specialization, reduced sense of smell, increased sense of vision, neocortex expansion. Grasping hands and feet, forward-facing eyes, changes in diet, greater visual capacity all came with arboreal settings. Most primates are arboreal, and live in tropical or subtropical climates of the new and old world. Primates are omnivorous they have incisors for cutting/biting and molars for chewing (specialized dentition) Grasping ability for hands and feet, opposable thumb, partially opposable big toe, tactile pads with nerve fibers at the end of digits. Many monkeys can grasp with opposable thumb but some have very reduced thumbs. Humans and chimpanzees are capable of precision grip.
