The Human Animal The Human Timescale

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Geological Timescale Species

Millions of Years

● A population or Periods group of populations Permian Triassic Jurassic Cretaceous Tertiary Quat. Major events that are capable of interbreeding and that can produce Dinosaurs Development and Human viable and fertile Evolve and Expand Diversification of Evolution Start of Abundance of Flowering Age of offspring Age of Large Herbivore Plants Mammals Dinosaurs Reptiles Mule 3 4 BIO 1300: The Human Animal BIO 1300: The Human Animal

Primate Evolution Primate Ancestor

● Pen-tailed tree shrew

● Ecologically similar New World Old World Lemurs Pottos monkeys monkeys Gibbons Orangutans Gorillas Chimpanzees Humans to squirrels 6 million years ago ● Tree-dwellers among branches ● Eats fruit and insects Ptilocercus

at least 65 million years ago Ancestral arboreal insectivore 5 6 BIO 1300: The Human Animal BIO 1300: The Human Animal

1 Primate Phylogeny Primate Evolution Hominids

● Primates : Hominoids – Primitive, smaller bodies and brains: Prosimians • Lemurs and Tarsiers

– Large bodies and brains: Anthropoids Simians/Anthropoids

Prosimians

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Prosimians and Monkeys

Marmosets Tamarins Capuchins Family Howler Spider Hominidae: The Great Guenon Macaque Apes Baboon Mandrill Langur Proboscis

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Humans 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)

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2 Evolution of the Primate Hand Evolution of Brachiation

● Efficient way of moving around branches ● Accompanied by greater dexterity and diversity of uses of arms and hands

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Primate Hands Primate Characteristics and Feet ● Reduced snout ● Opposable thumbs – Increased visual and big toe acuity instead ● Fingers and toes ● Reduced number of Red-ruffed Lemur have flat nails teeth but increased – Exception: toilet claw diversity (heterodonty) – Incisors to shear – Canines to slice – Pre-molars to crush Galago – Molars to grind 15 16 BIO 1300: The Human Animal BIO 1300: The Human Animal

Primate Vision Binocular Vision

● Eyes facing forward – Binocular vision – Depth-perception and 3-D – Well-developed occipital lobe

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3 Reduced Reproductive Rate Evolution of Bipedalism

● Carrying offspring in trees ● Emphasis on care and learning

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Human Lineages Sub-Fam

6 million 5 million 4 million 3 million 2 million 1 million Present Homininae (7MYA)

Homo sapiens ● Paranthropus boisei Sahelanthropus tchadensis

Australopithecus afarensis ● Chad, Africa 7-6 MYA

Paranthropus robustus ● Size of a chimp ● Probably bipedal Ardipithecus ramidus Australopithecus africanus Homo neanderthalensis – Ventral position of foramen magnum Brain = 320-380 cc

Australopithecus anamensis

Homo erectus

Paranthropus aethiopicus Homo ergaster

Homo habilis

Homo heidelbergensis

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Hominins Hominins ● Ardipithicus ramidus ● Orrorin tugenensis ● Ethiopia, Africa (4.5-4.3 MYA) ● Kenya, Africa (6.2-5.6 MYA) ● First complete skeleton ● 20 specimen found (female) ● Not sure if direct human ● Brachiating hands and arms ancestor or side branch ● Opposable toe 300-370 cc ● Bipedal femur but flat foot ● Long fingers (arboreal) adapted for ● Frugivorous or walking granivorous teeth 23 24 BIO 1300: The Human Animal BIO 1300: The Human Animal

4 Hominins Hominins Paranthropus bosei ● Paranthropus (3 species) ● Australopithecus afarensis 1.51m ● Ethiopia, Kenya, Tanzania (1973) 1.05 m ● 2.7-1.3 MYA ● Tanzania, Ethiopia, Kenya (3.7-3 MYA) ● Lived in humid habitats ● Sexual dimorphism ● Hundreds of skeletons found 474-545 cc ● Principally bipedal ● Fully bipedal but also arboreal ● Broad teeth, large sagittal ● Pronounced sexual Male: Female crest 1.37 m 1.24 m dimorphism 49 kg 34 kg Tracks found in – Tough, herbivorous diet volcanic ash 380-550cc ● Used stone tools 25 26 BIO 1300: The Human Animal BIO 1300: The Human Animal

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 27 BIO 1300: The Human Animal

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