31.3 Vertebrates Primates (order Primates) Most are adapted to an arboreal life (in trees) Limbs are mobile Hands and feet have digits Opposable thumbs (sometimes big toes) Eyes in the front of the head Large, complex brain Generally give birth to one offspring at a time Extended period of juvenile dependency 2 suborders – prosimians and anthropoids

31.4 Human Evolution All primates share one common ancestor Prosimians (lemurs and tarsiers) were the first types of primates to diverge from the human line of descent African apes were the last group to diverge from our line of descent Molecular data suggest that the split between the ape and human lineages occurred about 6–8 million years ago (mya)

31.4 Human Evolution One of the most unfortunate misconceptions concerning human evolution is the belief that Darwin and others suggested that humans evolved from apes On the contrary, humans and apes shared a common apelike ancestor Today’s apes are our distant cousins, and we couldn’t have evolved from our cousins because we are contemporaries—living on Earth at the same time

Evolution of Primates Humans hominin Chimpanzees Hominines hominin Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. common ancestor Humans hominin Chimpanzees Hominines hominin common chimpanzee Hominids Gorillas Hominoids western lowland gorilla Orangutans Bornean orangutan Anthropoids Gibbons white-handed gibbon rhesus monkey Old World Monkeys capuchin monkey New World Monkeys Tarsiers ring-tailed lemur Philippine tarsier Prosimians Lemurs 70 60 50 40 30 20 10 Million Years Ago (MYA) PRESENT

Comparison of human and chimp Genome

ORDER: Primates CLASSIFICATION • Adapted to an arboreal life Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. ORDER: Primates • Adapted to an arboreal life • Prosimians, Anthropoids CLASSIFICATION FAMILY: Hominidae (hominids) SUBFAMILY: Homininae (hominines) TRIBE*: Hominini (hominins) Early Humanlike Hominins Sahelanthropus, ardipithecines Later Humanlike Hominins australopithecines GENUS: Homo (humans) Homo habilis, Early Homo Homo rudolfensis, Brain size greater Homo ergaster, than 600 cc; tool use Homo erectus and culture Later Homo Homo heidelbergensis, Brain size greater Homo neandertalensis, than 1,000 cc; tool Homo sapiens use and culture

Human Evolution Sahelanthropus tchadensis Australopithecus afarensis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Sahelanthropus tchadensis Australopithecus afarensis Paranthropus robustus Homo habilis Homo sapiens Homo sapiens Homo neandertalensis Homo heidelbergensis Homo erectus Homo ergaster Homo rudolfensis Australopithecus garhi Homo habilis Australopithecus africanus Australopithecus afarensis Australopithecus anamensis Paranthropus aethiopicus Paranthropus boisei Ardipithicus ramidus Paranthropus robustus Sahelanthropus tchadensis 7.5 7 6.5 6 5.5 5 4.5 4 3.5 3 2.5 2 1.5 1 0.5 Million Years Ago (MYA)

31.4 Human Evolution Australopithecines Evolved in Africa 4 million years ago Went extinct about 1 million years ago Small brain (apelike) and walked erect (humanlike) Mosaic evolution Meaning that different body parts changed at different rates and therefore at different times No evidence of tool use Some were “gracile,” others robust “Lucy”

Australopithecus afarensis

31.4 Human Evolution Homo habilis and Homo rudolfensis First people to use stone tools Socially organized Probably scavengers Omnivorous – smaller cheek teeth Larger brain Less protruding face

Homo habilis

31.4 Human Evolution Homo ergaster and Homo erectus Fossils date between 1.9 and 0.3 million years ago Larger brain than H. hablis Flatter face with projecting nose Stood erect with striding gait Evidence of migration from Africa to Asia Tools were advanced compared to compared to H. hablis First to use fire – may have cooked meet

Homo ergaster neck of femur femur Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. neck of femur femur

31.4 Human Evolution Homo floresiensis 2007 study supports the hypothesis that this hominin evolved from normal- sized, island hopping Homo erectus Small in size compared to other hominids Island dwarfing Likely co-existed with modern Homo sapiens

Homo ergaster evolves into modern humans in Asia, Africa, and Europe. 31.4 Human Evolution Evolution of Modern Humans Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. ASIA AFRICA EUROPE ASIA AFRICA EUROPE 0.1 0.1 Homo sapiens Homo sapiens Homo sapiens Homo sapiens Homo sapiens Homo sapiens Homo ergaster evolves into modern humans in Asia, Africa, and Europe. Homo sapiens interbreeding 1 Millions of Years Ago (MYA) 1 Millions of Years Ago (MYA) Modern humans evolve in Africa and migrate to Asia and Europe. interbreeding migration of Homo ergaster migration of Homo ergaster migration of Homo ergaster migration of Homo ergaster 2 2 Homo ergaster Homo ergaster a. Multiregional continuity b. Out of Africa (replacement model)

31.4 Human Evolution Neanderthals Homo neandertalensis Lived between 200,000 and 280,000 years ago According to the replacement model, Neanderthals were displaced by modern humans Massive brow ridges, protruding nose, jaws, and teeth Culturally advanced – used tools, cooked their food, buried their dead with flowers, may have had a religion

Neanderthals

31.4 Human Evolution Cro-Magnons Oldest fossils to be designated H. sapiens sapiens Modern appearance Made advanced stone tools, were the first to hunt with knives and spears Hunted cooperatively May have been the first to have language Culture included art - sculpture and painting

Cro-Magnons