Unformatted text preview: Week 8 Key Words
Reading: BA 6 & 7 (MPBA: 10 & 11) heterodontism endothermy carnivore/omnivore dental formula olfactory bulbs (rhinencephalon) pentadactyly/prehensile encephalization quotient humerus/radius/ulna femur/tibia/fibula foramen magnum orthograde ischial callousites convergence/frontation/ approximation binocular/stereoscopic vision diurnal/nocturnal Announcements Homework 3 and Quiz 6 is due on Friday, March 27th at 5pm. No Discussion Sections Next Week! Exam 2 is Wednesday, April 1st Primates - Taxonomic Classification Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Mammalia Order: Primate Primate Traits Traits primates have in common with other mammals: A number of primate traits differentiate them from other animals Body hair Long gestation/live birth Mammary glands Heterodontism Endothermy Increased brain size Increased learning and behavioral flexibility A) Primate Dentition Retention of distinct tooth types Some mammals have lost tooth types Adaptation to generalized diet Less concentration on a single food source Incisors/canines for meat; molars for plants Primates are omnivorous Tooth Comb A) Primate Dentition Dental Formula:
Varies among primates Old World monkeys, apes and humans: 2:1:2:3 New World monkeys: 2:1:3:3 Primitive Mammalian: 3:1:4:3 B) Generalized Limb Structure Pentadactyl and prehensile Retention of clavicle Lower limb bones unfused (radius/ulna and tibia/fibula) C) Upright Posture Tendency toward upright (orthograde) posture Spine at an angle to the ground Associated with sitting, leaping, standing and walking Anterior shift of foramen magnum D) Nails Nails (flattened distal phalanges) replace claws on some digits Increased vascularization and nerve supply Tactile pads; fingerprints for gripping E) Reduced Sense of Smell Reduction in the size of the snout Reduction in turbinate bones Smaller olfactory bulbs Reduction in rhinencephalon F) Elaboration of Visual Apparatus Vision important in arboreal environment Food not tracked by scent None or rare territorial scent markings Judging tree distances, branch strength, and ripening fruit Expansion of occipital lobe F) Elaboration of Visual Apparatus Orbits isolated from the rest of the skull Eyes better protected Post-orbital bar Some have a bony cup (post-orbital plate) Ringtail Lemur Crania F) Elaboration of Visual Apparatus Orbital orientation: Convergence (eyes point forward) Frontation (orbits more vertical-relative to the tooth row) Approximation (eyes closer together) High degree of expression of these traits result in binocular vision 3D vision (stereoscopic) vision allows acute depth perception G) Elaboration of the Brain Increase in brain fissures (wrinkling) Greater surface area for synapses to operate Increase in total volume Increase in encephalization quotient (EQ): brain size/body size H) Increased Socialization Tendency for single births Longer infant/child dependency and longer life spans Greater dependency on flexible, learned behavior Infants dependent on others for survival Primates born premature and undergo significant postnatal development High parental investment (K-selection) Next Week Primate Fossils Geologic Timescale ...
View Full Document