Primate Introduction Lecture Notes PDF

9. What are Primates? Anthropology 201 Winter 2018  Objectives At the end of lectures students should: Know the defining features of primates Know the basic taxonomy of primates (2 main groups, their infraorders and superfamilies) Be able to identify key trait...

9. What are Primates? Anthropology 201 Winter 2018  Objectives At the end of lectures students should: Know the defining features of primates Know the basic taxonomy of primates (2 main groups, their infraorders and superfamilies) Be able to identify key traits of each living group of primates Know representative species of the living primate groups and their characteristics Reading: Chapter 5 of textbook (up to p. 124) 2 Primates are an Order of Mammals Mammalian synapomorphies: – Warm blooded – Viviparity – Lactation & mammary glands These traits are primitive for primates – Shared with last common ancestor and with all other mammals 3  Distribution of living nonhuman Primates Found in mostly tropical areas: in C. & S. America, Sub-Saharan Africa, parts of Mediterranean Africa, Saudi Arabia, Madagascar, Tropical Asia (up to Himalayan foothills), Japan 4  Primate Characteristics 1. Grasping Hands & Feet 2. Sensory System 3. Large Complex Brains and Associated Behaviour 4. Dental specializations, but generalized skeleton 5 1. Grasping Hands & Feet Opposable thumb and hallux (big toe) Nails, not claws Sensitive tactile pads Power Grip – Squeeze an object strongly between finger pads and palm, allows full strength of the forearm muscles to be applied (tennis racket grip) Precision Grip – Use just the tips of your fingers - for fine control (picking up a grape) 6 2a. Sensory systems - Vision Forward facing eyes – Stereoscopic vision – Depth perception Greater reliance on vision – Elaboration of the visual centers of the brain Colour vision – at least dichromatic (blue, green), many trichromatic (RBG) 7  2a. Cranial Anatomy to protect the eye All primates have a postorbital bar Higher primates (haplorhines) have postorbital closure Non-primate mammals generally only have postorbital process 8 2b. Sensory System - Olfaction Reduced reliance on olfaction Reduction of the snout Reduction of the olfactory centers of the brain 9 3. Large, Complex Brains Large brains relative to body size – Indian elephant = 5,400 cc – Modern human = 1,350 cc; African ape = 275-400 cc – But primates 2x larger than other mammals their size, humans 7-8x – Also many folds - sulci & fissures - to increase surface area Human Rabbit (not to scale!!) 10 3. Large, Complex Brains Learning & socialization very important for survival Greater reliance on learning linked to reduction in reliance upon instinct 11 3a. High Investment in Offspring Fewer offspring, but greater investment in rearing them – Usually means longer lived – Typically give birth to a single young (not litters) Infants are relatively altricial – “requiring nourishment” – vs. precocial (e.g. ungulates) Cling to mother, not left in nests (usually) - have grasping hands (even humans) Longer juvenescence (juvenile development period) 12  3b. Tendency Toward Sociality 13  4. Dental Formula Ancestral mammal condition = 3.1.4.3 Primitive primates (most strepsirhines & NWM) = 2.1.3.3 Later primates (OWM, Apes, Humans) = 2.1.2.3 Chimpanzee 2.1.2.3 dental formula (chimpanzee - 32 teeth in total) 14 4. Dental specializations Colobus Gorilla 15  4. Generalized skeleton Generalized limb structure Generalized, flexible morphology Non-specialized physical form By Unkown (Brehms Tierleben, Small Edition 1927) [Public domain], via Wikimedia Commons 16  Two points to remember Not all of these traits characterize all primates (e.g. no grasping toe in humans) None of these traits is unique to primates (e.g. dolphins have relatively large brains too) but together this suite of traits is only found in primates 17  Primates Apes Lemurs & Lorises Tarsiers manigerz34.files.wordpress.com/2009/06/7969-philippine-tarsier-0.jpg Platyrrhine Cercopithecoid Humans Monkeys Monkeys 18  Taxonomy Reminder Our taxonomic classification system is hierarchical: – 7 main levels – Kingdom, Phylum, Class, Order, Family, Genus, Species Animalia, Chordata, Mammalia, Primates, Hominidae, Homo, sapiens – Many sublevels, e.g. superfamily, infraorder, etc… – See p. 117 of textbook (Figure 5.9) Same as Table 5.2 in the 8th and 9th of the textbook and Table 5.3 in the 6th and 7th editions. 19 Primates are divided into two groups*: Strepsirrhines Haplorrhines Platyrrhine Cercopithecoid Lemurs Galagos Lorises Tarsiers Monkeys Apes Monkeys Primate Phylogeny * Variably considered as semiorders or suborders  Strepsirrhine Characteristics: Found in Sub-Saharan Africa, Madagascar & Asia 21  Strepsirrhine Characteristics Primate Galago characteristics! Most are nocturnal large eyes Post-orbital bar only Rely on scent marking (olfaction) more so than haplorhines Slow loris 22  Strepsirrhine Characteristics Dental comb Grooming claw – On 2nd digit of the foot Both used in personal grooming Note the canine-like premolar! 23  Lemuriformes Characteristics Strepsirrhines Lemuriformes Lorisiformes Only found on Madagascar & neighbouring Comoros Islands (endemic) Diverse! Because of endemism and lack of competition Small and medium-sized today Diurnal and nocturnal Female dominance 5 families – Know representative examples from the text and film – don’t memorize the five families! 24 Lorisiformes - Characteristics All are nocturnal and small bodied Generally solitary or in small family units Eat insects, gum and nectar, some fruits Two Families: Lorisidae -often immobile Galagidae -slow movers -very active -Africa and Asia -fast movers -Africa only 25 Suborder Haplorrhini - Haplorrhines Order Primates Suborder Strepsirhini Haplorhini Infraorder Lemuriformes Lorisiformes Tarsiiformes Platyrrhini Catarrhini lemurs lorises, galagos tarsiers NW monkeys OW monkeys, apes Tarsiers, monkeys, apes, and humans Three infraorders More ‘derived’ primates 26  Haplorrhine Characteristics Diurnal (except tarsiers & owl monkeys) Reduced reliance on smell & hearing – Flatter faces, shorter snouts Larger, more complex brains – Longer juvenile dependency – Increased parental care/investment – Increased social complexity 27  Enigmatic Tarsiers Infraorder Tarsiiformes Only one living genus (Tarsius) Retain primitive morphology – Same genus applied to fossil from middle Eocene in China (~ 45 mya) Superficially they look like strepsirrhines, so used to be classified in Strepsirrhini – Nocturnal – Small Genetics tells us that they are haplorrhines! 28  Haplorrhini Order Primates Suborder Strepsirhini Haplorhini Infraorder Lemuriformes Lorisiformes Tarsiiformes Platyrrhini Catarrhini lemurs lorises, galagos tarsiers NW monkeys OW monkeys, apes “Higher primates” – can be classified together as Anthropoidea 29 Platyrrhini: broad, outward-facing nostrils 2.1.3.3. dental formula Catarrhini: narrow, downward-facing nostrils 2.1.2.3 dental formula 30  Platyrrhini - Platyrrhine Monkey Characteristics Five families Found in the Americas (Mexico, Central and South America) Arrived from Africa around 35 Ma 31 * Also called the “New World Monkeys”, but many primatologists now avoid that terminology Characteristics of Platyrrhines All have tails Several have prehensile tails All arboreal Smaller body size than cercopithecoid monkeys Most have 2.1.3.3 dental formula Minimal sexual dimorphism Diurnal (except Aotus – the owl monkey) 32  Catarrhine Classification Catarrhini Infraorder Cercopithecoidea Hominoidea Superfamily Cercopithecidae Hylobatidae Pongidae Hominidae Family Cercopithecinae Colobinae Subfamily Two major subdivisions: cercopithecoid monkeys (Cercopithecoidea) & apes (Hominoidea) 33  Superfamily Cercopithecoidea: Found in wide variety of environments – tropical Asia, sub-Saharan Africa, North Africa, Arabian Peninsula All diurnal Single births Some species are terrestrial Larger body size, often sexually dimorphic 34  Two Subfamilies Fruit eaters Leaf eaters Broad Narrow incisors incisors Low cusps High cusps Cheek pouches No cheek Simple pouches stomach Complex Shorter stomach limbs Long limbs Cercopithecinae Colobinae 35 Subfamily Baboon Cercopithecinae Africa and Asia Baboons, macaques, vervets, guenons…) Wide range of habitats Vervet – Savanna, woodlands, rain forests, deserts, cities, mountains Diet highly variable – Fruits, grasses, roots, tubers, leaves, insects Highly variable social systems – Many multi-male/multi-female groups Mandrill Most are sexually dimorphic More terrestrial species than in any other primate group 36 Subfamily Colobinae Found in Africa and Asia 6-12 kgs Procolobus All arboreal Colobus Specialized folivores – Sacculated stomach, supports bacteria for Semnopithecus digestion of cellulose – High shearing crests on teeth Rhinopithecus Nasalis 37  Superfamily Hominoidea The Apes No tails Larger size and weight Larger brain to body weight ratio More upright posture Longer gestation and maturation 38 Hominoid Distribution 39  Family Hylobatidae: “Lesser Apes” Gibbons & Siamangs Southeast Asia Pair-bonded (“monogamous”) – Sexually monomorphic Siamang Frugivores Move using brachiation – Long strong arms, short legs, elongated hook-like fingers Highly territorial – Singing calls Gibbon 40  Family Hominidae: “Great Apes” Genus Pongo: Orangutans Genus Gorilla: Gorillas Genus Pan: Chimpanzees & Bonobos Genus Homo: Humans Large bodied Suspensory locomotion in trees (NOT brachiation); knuckle- walking or ”fist-walking” on the ground Sexually dimorphic Advanced cognitive abilities (all show tool use) Diverse diets & social systems Most investments in offspring – intense parenting and prolonged juvenile periods 41  Strepsirrhines Haplorrhines Platyrrhine Cercopithecoid Lemurs Galagos Lorises Tarsiers Monkeys Apes Monkeys Primate Phylogeny