Study Guide for Exam 2 Human Evolution Raghanti Know what characteristics define primates as mammals and those characteristics that define primates as Primates as Mammals Primate Characteristics primates Body hair fur Long gestation live birth Mammary glands Heterodonts different teeth Homoeothermic Increased brain size Capacity for learning and behavioral flexibility Five digits on their hands and feet pentadactyl Convergent orbits Primates have retained a clavicle Grasping hand and feet Opposable thumbs Postorbital bar or fully enclosed orbit Tactile sensitivity and nails Tendency towards erect posture Big brains Reduced olfactory area in brain Better eyesight Delayed maturation long juvenile period Ancestral homology Stereoscopic binocular vision Primates eat an omnivorous Most primates are partially or totally arboreal tree living Greater dependence on learned behavior Tendency to live social groups with males Diurnal activity patterns apes and humans Characteristics Prosimians More laterally placed eyes Shorter gestation maturation dental comb Grooming claw Mandible that it s not fused The most primitive primates Small bodied nocturnal solitary Few are social some are diurnal Anthropoids Monkeys apes and humans Larger body size Larger brains Reduced olfaction Increased reliance on vision Fully enclosed eye orbits Fused mandible Longer gestation maturation Increased parental car Catarrhines Downward noses Like humans Platyrrhines Big nose holes Uniquely Human Traits Know the differences between anthropoids and prosimians between platyrrhines and catarrhines and between Know the taxonomy as discussed in class as per handout At what level do chimpanzees and humans diverge Know the second taxonomic division i e alternate Suborders for primates and why and for what genus it Human are bipedal Concealed Ovulation Big Brains 3x larger brain than expected Major adaptive response in cultural Females are continuously receptive Language and tool use lots of critters use tools Suborders Prosimian Lemurs Loris Bushbabies Galago Tasier was changed Order Primate Suborder Lines of evidence 4 Tarsier Strepsirhine Wet nose rhinarium Lemurs Loris Bushbabies Anthropoids OWM NWM Apes Humans Haplorhine Dry nose OWM Apes Humans NWM Tasieer No Rhinarium No Tapetum Lucidum Fully enclosed orbit DNA evidence Closer to anthropoids Know what each number in the dental formula corresponds to in terms of tooth type Incisors canines premolars and molars Know the dental formula for callitrichids New World Monkeys except the callitrichids and Old World 0 Monkeys apes and humans 2 1 3 3 Cebids and Atelids NWM 2 1 3 2 Callitrichids NWM 2 1 2 3 OWM Apes Humans 3 1 4 3 Placental Mammal Ancestor Know the difference between primitive and derived traits specialized vs generalized Primitive older ancestral o o Derived more newly evolved specialized Know what derived traits characterize different groups of primates e g twinning cheek pouches ischial callosities prehensile tails etc NWM prehensive tail Routinely birth twins One Female with 2 or more males Males are paternal Carrying the offspring Reproductive suppression of subordinate females by males OWM Cheek pouches ischial callosities butt pads Leaf eating monkeys Specialized teeth for sheering leaves Specialized gut to ferment leaves enlarged cecum APES No tail Short back Be familiar with the geographic distribution of primates Prosimians OWM Africa and Asia NWM South and central America Apes Orangutans Asian our least closest relative Gorillas Chimpanzees Binobos Africa Review the different primate locomotion patterns and the physical characteristics associated with each Quadruped moving on 4 limbs long flexible spines for monkey tails Terrestial quadrupets normal shorter tails Arboreal Quadruped above tree walkers Long legs than arms long tail Clingers and leapers arboreals strong legs really short arms Brachiators alboreal Really long arms Biped Walking on two feet Humans Knuckle walking apes sometimes Know the two hypotheses for primate evolution arboreal adaptation Cartmill person Visual Predation hypothesis Sussman person Angiosperm radiation Preying on insects in terminal branches of tress Taking advantage of fruit and flowering tress Are humans the only species that possess language Why are chimpanzees incapable of producing spoken language Humans posses language but animals can still communicate Their vocal cords are located higher in their throats Know what primate socioecology behavioral ecology is Evolutionary basis for animal behavior due to ecological pressure Environment is selecting for behaviors Be able to list and describe differences between nonhuman primate social groups e g marmosets and tamarins both have twins and the males do most of the parenting Sexual Dimorphism means when there is a competition for females Polygyny Many Females one male multiple females harem Ex Gorillas geiada baboons Strict Dom Hierarchy High sexual dimorphism Polygamy many gametes multiple males and multiple female Ex Competition for resources and females High sexual dimorphism body and canine size Monogamy pair bond between male and female Polyandry one female multi male Ex Gibbons and Siamangs Maternal and paternal behavior Little or no sexual dimorphism Ex marmosets and tamarins twins much paternal care no sexual dimorphism Solitary noyau Ex Prosimians orangutans Core of any group mother and offspring Dispersal Young must leave the natal group Ex Often just sex males or females many times females stay in natal group Know the difference between hominoid and hominid Hominoid Human and Apes Hominid Humans and bipedal ancestors must be bipedal Know what sexual dimorphism is and in what mating strategies it is most pronounced Sexual Dimorphism Phenotypic Difference b t males and females EX Body size Canine size Fur color Antlers Peacocks tails It is really pronounced in strict dominant Hierarchy and Polygamy Know what philopatry is Philopatry staying in the natal group One or more sexes must leave natal group to avoid in breeding What are the two hypotheses put forth for social living among primates 0 Resource defense model can defend your resources from other groups 1 Predator avoidance More eyes to scan for predators What is the basic social unit in all primate species Dominance Hierarchies The more strict hierarchies are the more competition for resources and mates More sexual dimorphism which is body and canine size High Rank means better resources Better