McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 1 7 Primate Evolution Anthropology: The Exploration of Human Diversity 11 th Edition Conrad Phillip Kottak

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 2 Primate Evolution Fossils and Chronology Early Primates Miocene Hominoids A Missing Link?

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 3 Fossils and Chronology –Epocene epoch is age of prosimians –Ensuing Miocene epoch witnessed fluorescence of prototypes Primate order evolved by exploiting new opportunities at the end of Mesozoic era, about 65 million years ago

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 4 Fossils and Chronology Fossil record gives merest glimpse of diverse bioforms Common ancestor of humans, chimps, and gorillas lived during the late Miocene, some 5 to 8 million years ago Conditions favoring fossilization open special “time windows” for certain places and times

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 5 Fossils and Chronology –Paleozoic—era of ancient life with fishes, amphibians, and primitive reptiles –Mesozoic—era of middle life with reptiles, including dinosaurs –Cenozoic—era of recent life with birds and mammals History of vertebrate life on earth is divided into three eras

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 6 Fossils and Chronology –Tertiary Tertiary period has five epochs: Paleocene; Eocene; Oligocene; Miocene; and Pliocene –Quaternary Quaternary includes two epochs: Pleistocene and Holocene (recent) Anthropologists are concerned with the Cenozoic era, which includes two periods:

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 7 Fossils and Chronology Geological Time Scales –Insert Figure 7.2 (will need two slides)

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 8 Fossils and Chronology Geological Time Scales (continued) –Insert Figure 7.2 (will need two slides)

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 9 Early Primates Arboreal theory—primates became primates by adapting to arboreal life –Importance of sight over smell –Depth perception facilitated leaping –Grasping hands and feet During Cenozoic, most land masses had tropical or subtropical climates

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 10 Early Primates Visual predation hypothesis— binocular vision, grasping hands and feet, and reduced claws developed because they facilitated the capture of insects Early primates first adapted to life in the bushy forest undergrowth and low tree branches

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 11 Early Primates Placement of Continents at the End of the Mesozoic –Insert Figure 7.3

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 12 Early Primates –The earliest primates date to the first part of the Cenozoic, the Paleocene (65-54 m.y.a.). Early Cenozoic Primates

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 13 –The Eocene (54-38 m.y.a.) was age of prosimians with at least 60 different genera in two families Omomyid family—lived in North America, Europe, and Asia Early Primates May be ancestral to all anthropoids Early Cenozoic Primates Adapid family—ancestral to the lemur-loris line

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 14 Early Primates –Anthropoids branched off from the prosimians during the Eocene Anthropoid eyes rotated more forward compared to prosimians Anthropoids have a fully enclosed bony eye socket Anthropoids have a dry nose separate from the upper lip Anthropoids have molar cusps Early Cenozoic Primates

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 15 Early Primates –During the Oligocene (38-23 m.y.a.), anthropoids became most numerous primates –Parapithecid family—ancestral to the New World monkeys –Propliopithecid family—may be ancestral to Old World monkeys, apes, and humans Oligocene Anthropoids

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 16 Miocene Hominoids Earliest hominoid fossils date to the Miocene epoch (23-5 m.y.a.)

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 17 Miocene Hominoids –Proconsul represents most abundant and successful anthropoids of early Miocene Proconsul (P.) africanus P. nyanzae P. major Proconsul

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 18 Miocene Hominoids –Skeleton below the neck the skeleton more monkey-like Teeth suggest that they ate fruits and leaves Probably moved through trees like a monkey— on four limbs Proconsul –Teeth similar to those of living apes

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 19 Miocene Hominoids Monkeys’ superior ability to eat leaves Monkey molars developed lophs, which enhanced their ability to chew leaves –Some Proconsul species may have been ancestral to living African apes Proconsul –By middle Miocene (16-10 m.y.a.) replaced by Old World monkeys and apes

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 20 Miocene Hominoids –Primitive traits—traits passed on unchanged from an ancestor –Derived traits—traits that develop in a particular taxon after they split from their common ancestor Traits

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 21 Miocene Hominoids –Afropithecus—large, slow-moving Miocene hominoid with large projecting front teeth from northern Kenya (18-16 m.y.a.) Recent research suggests that the two species of Kenyapithecus should be reclassified as Equatorius africanus. Afropithecus and Kenyapithecus

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 22 Miocene Hominoids –Equatorius and Afropithecus are probable stem hominoids—species somewhere on evolutionary line near the origins of the modern ape group Too primitive to be considered direct ancestors of living apes and humans Afropithecus and Kenyapithecus

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 23 Miocene Hominoids –Belongs to ramapithecid genera along with Gigantopithecus –Seen to be ancestral to the modern orangutan Sivapithecus

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 24 Miocene Hominoids Gigantopithecus –Largest primate that ever lived Based on ratios of jaw and tooth size to body size in other apes, with the largest estimate having Gigantopithecus standing over 10 feet tall and weighing 1,200 pounds

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 25 Miocene Hominoids Probably ate grasses, fruits, seeds, and bamboo Some wrongly suggest it is still alive as the yeti and Bigfoot Gigantopithecus –Must have been a ground-dwelling ape

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 26 Miocene Hominoids –Lived in Europe during the middle and late Miocene –Probably includes the common ancestor of lesser apes (gibbons and siamangs) and great apes –Has Y-5 arrangement of molar cusps typical of Dryopithecus and hominoids Dryopithecus

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 27 Miocene Hominoids –Oreopithecus bambolii lived between 7 to 9 million years ago –Apparently spent much of its time standing upright and shuffling short distances –Its big toe splayed out 90 degrees from the other toes Oreopithecus

McGraw-Hill © 2005 The McGraw-Hill Companies, Inc. 28 A Missing Link? Humans and African apes share common ancestor Over time all three species evolved and diverged Humans not descended from gorillas or chimps