Human Evolution

Chapter 17

Primates

• Order primates includes prosimians, monkeys, apes, and humans– Adapted for an arboreal life

Human Evolution

• Humans and apes have a common ancestor– Misconception: Humans evolved from apes

• The human lineage and ape linage split around 6 million years ago

• Humans and chimpanzees are the most closely related– share around 99% of our DNA

Ancestralprimate

Lemurs, lorises,and pottos

Tarsiers

New World monkeys

Old World monkeys

Gibbons

Orangutans

Gorillas

Chimpanzees

Humans

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Figure 17.36

Human Evolution

• All primates share one common mammalian ancestor – Other primates diverged from the

lineage• Prosimians

– lemurs and tarsiers– First primates to diverge

• Anthropoids – New World monkeys, Old World

monkeys, and hominoids (apes and hominids)

Human Evolution• Proconsul

– Probable link between monkeys and apes (about 15 mya)

– About the size of a baboon

– Probably ancestral to dryopithecines • All apes arose from about 10 mya• Hominids can also trace their lineage to the dryopithecines

Human Evolution

• Evolution of Hominids

– To be a hominid a fossil

must have anatomy

suitable for standing and

walking erect (bipedalism)

• Bipedalism made food

gathering easier

– Believed that hominids

appeared approximately 6

million years ago

Ardipithecusramidus

Australopithecusafarensis

Australopithecusafricanus

Paranthropusrobustus

Paranthropusboisei

Homoneanderthalensis

Homosapiens

Homohabilis

Homo erectus

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6.0

5.0

5.5

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

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Figure 17.38

Human Evolution

• Australopithecines

– Evolved in Africa 4 million years ago, went extinct

about 1 million years ago

– Australopithecines had a small brain and walked erect

– No evidence of tool use

– Some were gracile (slender), others were robust

(powerful)

Australopithecus afarensis

Human Evolution

• Evolution of Early Homo

– Earliest fossils are about 2 million years old

• Larger brain than Australopithecines

• Jaws and teeth resemble humans

• Evidence of tool use

Human Evolution

• Evolution of Early Homo – Homo habilis-

• Brain size as large as 772 cc; enlarged speech areas• Smaller cheek teeth indicates an omnivorous diet• Findings indicate tool use

– Crude tools made of stone• Culture

– Encompasses behavior and products– Hunter and gatherers may have eaten together

and shared food

Human Evolution

• Evolution of Early Homo

– Homo ergaster and Homo erectus

• Fossils date between 1.9 and 0.3 million years ago

• Larger brain than H. hablis

• Stood erect, gait was similar to humans

• Evidence of migration from Africa to Asia

• Tools were advanced compared to compared to H. hablis

• First to use fire

• Systematic hunters

Homo ergaster

Human Evolution

• Evolution of Early Homo

– Homo floresiensis

• Evolved from Homo erectus

• Small in size compared to other hominids

• Likely co-existed with modern Homo sapiens

Human Evolution

• Evolution of Modern Humans

Human Evolution

• Neanderthals– Lived between 200,000 and 28,000 years ago

– Massive brow ridges, protruding nose, jaws, and teeth

– Low, sloping foreheads

– Larger brain than H. sapiens, heavily muscled

– Culturally advanced

– According to the Out-of Africa hypothesis,

Neanderthals were displaced by modern humans

Neanderthals

Human Evolution

• Cro-Magnons

– Oldest fossils to be designated H. sapiens sapiens

– Modern appearance, made compound 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