The Human Animal The Human Timescale Geological Timescale Millions of Years Periods Permian Triassic Jurassic Cretaceous Tertiary Quat. Major events Dinosaurs Evolve and Expand Start of Age of Reptiles Human Development and Evolution Diversification of Flowering Abundance of Age of Plants Large Herbivore Mammals Dinosaurs 1
Species A population or group of populations that are capable of interbreeding and that can produce viable and fertile offspring Mule Primate Ancestor Pen-tailed tree shrew Ecologically similar to squirrels Tree-dwellers among branches Eats fruit and insects Ptilocercus Primate Evolution Lemurs Pottos New World Old World monkeys monkeys Gibbons Orangutans Gorillas Chimpanzees Humans 6 million years ago at least 65 million years ago Ancestral arboreal insectivore 2
Primate Evolution Primates : Primitive, smaller bodies and brains: Prosimians Lemurs and Tarsiers Large bodies and brains: Simians/Anthropoids Primate Phylogeny Hominids Anthropoids Prosimians Prosimians and Monkeys Marmosets Tamarins Capuchins Howler Spider Guenon Macaque Baboon Mandrill Langur Proboscis 3
Family Hominidae: The Great Apes Our Common Ancestor Probably had many traits in common with modern Chimps and Bonobos Diet of fruit Lived in mixed-habitats Used tools Hunted small animals/ insects Culture (Transmission of non-genetic traits) 4
Evolution of Brachiation Efficient way of moving around branches Accompanied by greater dexterity and diversity of uses of arms and hands Evolution of the Primate Hand Primate Hands and Feet Opposable thumbs and big toe Fingers and toes have flat nails Red-ruffed Lemur Exception: toilet claw Galago 5
Primate Characteristics Reduced snout Increased visual acuity instead Reduced number of teeth but increased diversity (heterodonty) Incisors to shear Canines to slice Pre-molars to crush Molars to grind Primate Vision Eyes facing forward Binocular vision Depth-perception and 3-D Well-developed occipital lobe Binocular Vision 6
Reduced Reproductive Rate Carrying offspring in trees Emphasis on care and learning Evolution of Bipedalism Human Lineages 6 million 5 million 4 million 2 million 3 million 1 million Present Homo sapiens Paranthropus boisei Australopithecus afarensis Paranthropus robustus Ardipithecus ramidus Australopithecus africanus Homo neanderthalensis Australopithecus anamensis Homo erectus Paranthropus aethiopicus Homo ergaster Homo habilis Homo heidelbergensis 7
Sub-Fam Homininae (7MYA) Sahelanthropus tchadensis Chad, Africa 7-6 MYA Size of a chimp Probably bipedal Ventral position of foramen magnum Brain = 320-380 cc Orrorin tugenensis Kenya, Africa (6.2-5.6 MYA) 20 specimen found Not sure if direct human ancestor or side branch Bipedal femur Long fingers (arboreal) Frugivorous or granivorous teeth Ardipithicus ramidus Ethiopia, Africa (4.5-4.3 MYA) First complete skeleton (female) Brachiating hands and arms Opposable toe 300-370 cc but flat foot adapted for walking 8
Australopithecus afarensis (1973) Tanzania, Ethiopia, Kenya (3.7-3 MYA) Hundreds of skeletons found Fully bipedal but also arboreal Pronounced sexual dimorphism 380-550cc 1.51m 1.05 m Tracks found in volcanic ash Paranthropus (3 species) Ethiopia, Kenya, Tanzania 2.7-1.3 MYA Lived in humid habitats Sexual dimorphism Principally bipedal Broad teeth, large sagittal crest Tough, herbivorous diet Paranthropus bosei 474-545 cc Male: 1.37 m 49 kg Female 1.24 m 34 kg Used stone tools Homo Smaller faces, jaw not prognathous Smaller molars but bigger incisors and canines Bigger brains Thorax and pelvis upright and slender Longer legs Shorter toes Culture 9
Questions? 10