26.3 Human Evolution

Classification Homo sapiens sapiens Kingdom Animalia Phylum Chordata 26.3 Homo sapiens sapiens Kingdom Animalia Phylum Chordata Class Mammalia Order Primates Family Hominidae Genus Homo Species Sapiens Subspecies Sapiens

Classification Humans are primates 26.3 Classification Humans are primates Shared most recent ancestor with chimpanzees ~6 mya

What is a Primate? Mammals with: 26.3 Mammals with: Long fingers and toes with nails instead of claws Flexible joints and limbs Binocular vision Well-developed cerebrum Most adaptations for arboreal (tree-dwelling) life

Long Fingers and Toes Allows firm grip 26.3 Long Fingers and Toes Allows firm grip Claws became nails to allow advanced grips

Opposable Thumbs Thumbs that can move against the other digits, 26.3 Opposable Thumbs Thumbs that can move against the other digits, Allows power grip and precision grip Most primates have these

26.3 Flexible Joints Limbs can rotate in broad circles around a strong shoulder joint Strong clavicle (collar bone) Well suited for climbing

Binocular Vision Ability to combine visual images from both eyes 26.3 Binocular Vision Ability to combine visual images from both eyes Provides depth perception and a three-dimensional view of the world

Large Cerebrum “Thinking” part of the brain is large and intricate 26.3 Large Cerebrum “Thinking” part of the brain is large and intricate Enables Complex behaviors Critical thinking Reasoning Many primates create elaborate social systems

Human Evolution Humans are unique because of Bipedalism Large brains 26.3 Human Evolution Humans are unique because of Bipedalism Large brains Advanced tool use Language and advanced culture

Bipedalism Walking on two legs Many skeletal changes 26.3 Walking on two legs Many skeletal changes Pelvis, hips, knees, back, etc. Main advantage: tool use

26.3 Bipedalism

26.3 Brain Size Increased

Jaws and Teeth got Smaller 26.3 Jaws and Teeth got Smaller Shift away from plant material in diet

Ancient Hominines Australopithecus afarensis 26.3 Ancient Hominines Australopithecus afarensis “Lucy” is one of the most famous human ancestor skeletons Lived 4-1.5 mya Bipedal apes but still very apelike Diet rich in fruit Good climber Spent significant time in trees

Ancient Hominines Homo habilis 26.3 Ancient Hominines Homo habilis Means “handy man” Significant tool crafting and use Speech possible

Ancient Hominines Homo erectus 26.3 Ancient Hominines Homo erectus 1.9 and 0.3 mya. Extremely successful and widespread Larger brain and flatter face than Homo habilis Much taller than previous hominids First hominid known to use fire

Ancient Hominines Homo erectus 26.3 Ancient Hominines Homo erectus

Ancient Hominines Homo neanderthalensis 26.3 Ancient Hominines Homo neanderthalensis 200,000 years ago Massive brow ridges with protruding nose, jaws, and teeth Heavily muscled Culturally advanced Manufactured variety of tools Still traces of Neanderthal DNA in humans today

Ancient Hominines Homo sapiens 26.3 Ancient Hominines Homo sapiens ~200,000 years ago Cro Magnon is name for early humans Advanced tools, communication, and culture Entered Europe ~100,000 years ago Interbred with Neanderthals Only hominine for past 24,000 years

26.3