HUMAN EVOLUTIONHUMAN EVOLUTION—— How Did We Get From How Did We Get From

There to Here? There to Here?

“The evolutionary design of man has intrigued humans for many years. It has lead anthropologists to travel the world in search of fossil evidence to learn who we have evolved from. Human evolution began roughly 5-10 million years ago when the human line split from the apes. Slowly scientists have tried to put the pieces together to give us an idea of our evolutionary line.”

Morphological Evidence for Morphological Evidence for Human EvolutionHuman Evolution

• The fossil record shows slow gradual changes in structure over time … cranium– Flattening of face– Centering of foramen

magnum– Reduction in canine size browridge size sagittal crest

Time

Common Ancestor

ChimpH. sapiens

P. boisei

A. africanus

A. aferensis

(“Lucy”)(“Lucy”)

H. erectus

H. neanderthalensis

H. habilis

????

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Things to Remember …Things to Remember …• Structural comparisons

provide one piece of evidence.

• Gradual accumulation of traits over time!

• Modern humans did NOT evolve from apes!! They evolved independently from a common ancestor!!

• Scientists disagree on the the hominid family tree!!

Uncertain ???

Common Ancestors in the Primate Family

Tree

Procunsul

ProcunsulProcunsul

• Common ancestor of anthropoids (monkeys, apes & humans)

• Most abundant primate during the Miocene

Procunsul fossil

• Split between apes & humans approx. 5-10 mya

• Common ancestor likely was small & ”ape-like” with few “human-like” traits

• Possibly more than one??• Several fossil candidates:

– “Toumai” ???– “Millennium Man” ???

• Identity is still uncertain!!

Common Ancestor of Common Ancestor of Chimps & Humans—Chimps & Humans—

Missing Link??Missing Link??

Some of Our Oldest, Some of Our Oldest, Most Distant RelativesMost Distant Relatives

• “Tomai” (6-7 mya)• “Millennium Man”

(5.7-6.1 mya)• Ardipithecus ramidus

kadabba (5.2-5.8 mya)

• Ardipithecus ramidus ramidus (4.4 mya)

“Tomai” was discovered in 2002 in a desert in Chad.

“Millennium man” bones were discovered in 2000 in Kenya.

• This group is thought to link older hominids (Ardipithecus) to younger hominids (Homo).

• The transformation from

ape-like features to modern human features characterize this group.

AUSTRALOPITHECINEAUSTRALOPITHECINE

• Existed from 4.2 - 3.9 mya • Discovered by Meave

Leakey in East Africa in 1995

• Characteristics:– Reduced pointy canines– Thick tooth enamel– More upright posture– Fingers long and curved– Elongated face– Diastema present

Australopithecus Australopithecus anamensisanamensis

• Existed from 3-4 mya• Lived in E. Africa• Primarily herbivorous• May have slept in trees to

avoid large predators• Characteristics:

– Small brain (35% modern)– Long arms– Short legs– Upright walker

Australpethicus Australpethicus afarensis—”Lucy” & Her afarensis—”Lucy” & Her

FamilyFamily

““Lucy”Lucy”

• Discovered by Johanson in 1974 in Ethiopia

• About 40% of her skeleton was found!

• She stood about 3'6" tall & likely weighed 62 lbs

Laetoli FootprintsLaetoli Footprints

• Found by Mary Leaky in Tanzania

• These footprints were evidence of bipedalism:– Strong heel strike– Splayed toes– Slight arch

Australopithecus africanusAustralopithecus africanus

• Existed from 2.3-3.0 mya• Found in South Africa• Characteristics:

– No saggital crest– Less prominent browridge– Smaller canines– Face less elongated– No diastema– Ape-like arms

Famous Famous A. africanusA. africanus FossilsFossils

• “Taung Baby”– 1st Hominid discovered (1924)– Child fossil (8 years old) – Evidence of African origins

• “Little Foot”– Big toe able to move out to

the side– Found stashed in a box

• “Mrs. Ples”– Further evidence of African

origins– Turns out to be “Mr. Ples”

Australopithecus garhiAustralopithecus garhi

• Existed 2.5 mya (Ethiopia)

• Found with many tools and an array of slaughtered animals

• Characteristics: – Canines like Homo genus– No diastema– Elongated face– Ape-like arms and legs

• Paranthtropus existed at the same time as the Australopithecines & some species of the Homo.

• Lived among great predators• May have been preyed upon by

members of the Homo genus!!• Distinguishing features:

– Robust skulls – Large saggital crest– Huge flat molars used for grinding

PARANTHROPUSPARANTHROPUS

““Nutcracker Man”Nutcracker Man”

• Paranthropus boisei (1.2-2.3 mya)• Open woodlands & grasslands• Primarily herbivorous

(nuts, seeds, & roots)• Lived in harems--1 male & many

females

• Characteristics:– Muscular bodies (about 100 lbs)– Large, flat face – Huge jaw & teeth– Thick tooth enamel– Small brain (39% modern)

Paranthropus robustusParanthropus robustus

• Existed 1-2 mya• Discovered in the

1930’s • Australopethecus

robustus • Named for the heavy

build of the fossil• Used bones as tools to

dig out tubers & termites

“Greek Lovers”

• Begins about 2.3 mya• Emergence of tool use,

language, & culture.• Distinguishing

characteristics:– Bigger brain (above 1000ml)– Straight-rising forehead – Rounder skull– Reduced teeth – Shorter arms & longer legs

HOMOHOMO

Homo habilisHomo habilis

• The earliest known Homo• Existed from 2.2 to 1.6 mya• “Handyman”--avid tool users• Scavenger• Characteristics:

– Larger brains (47% modern)– Flatter face– No browridge– Forehead present– Long arms

Small (baseball size), simple tools—Oldowan

Homo rudolfensisHomo rudolfensis

• Existed from 2.4 to 1.9 mya• Omnivorous scavenger• Likely competed with H.

habilis• Characteristics:

– Larger brains (56% modern)– Large body size; very tall (5’5”)– No browridge– Flatter face– Forehead present– Long arms

Homo ergasterHomo ergaster

• 1.9 mya-600,000 ya• “Workman”• Lived in desert

savannahs• Omnivorous scavenger• 1st to leave Africa—later

became H. erectus• Characteristics:

– Tall & muscular– Long legs– 74% modern brain size– Smooth skin for sweating

“Nariokotome Boy”

Homo erectusHomo erectus

• Lived 2 mya-400,000 ya• Fossils found in Africa,

Europe, & Asia• “Upright man”• Used more complex tools

(Acheulian) for many tasks & used fire

• Characteristics:– Large brain & thick

cranium– Sloping forehead– Large orbits & face “Turkana Boy”—one of the

most complete Homo skeletons

Homo floresensisHomo floresensis• “Hobbit”

– Discovered n 2004 on the Indonesian island of Flores

– 3 ft tall adult female– 95,000-13,000 ya– Small brain– Found w/ stone tools &

charred animal remains

• May have evolved from Homo erectus

• May have arrived on the island via a boat??

Homo heidelbergensisHomo heidelbergensis

• 500,000-100,000 ya• Found in Europe, Africa,

India, and China.• Used new advanced tools • Omnivorous• Proficient hunters• Characteristics:

– Muscular, tall (6 feet)– Large face & browridge– Large brain (90% modern)– Big frontal lobes--speech

"Neanderthal Man"

• H. neanderthalensis• 130,000 to 25,000 ya• Found in Europe, E. Asia,

and the Middle East.• Flourished in warm

periods & in the Ice Age.• Skilled hunters that

cooperated to make a kill• Relied heavily on meat

““Neanderthal Man”Neanderthal Man”

• Characteristics:– Better tools– Burial sites with tools,

ornaments & flowers– Cared for the disabled– Clothes & Shelters– Culture– Art & music (not

abstract)

"Neanderthal Man" • Physical characteristics:

– Stocky build (5’5”, 200 lbs)– Large muscles– Long, projecting nose– Large brain (12% larger)

• Extinction likely caused by competition with modern humans

• Likely not our direct ancestor—DNA analyses shows not closely related

Homo sapiensHomo sapiens

• “Knowing Man”• 130,000 ya-Present• Found Worldwide• Highly crafted tools• Complex social

organization• Omnivorous diet• “Cro-Magnon Man” is an

early H. sapiens that lived in W. Europe during the late Ice Age

Oldest (130,00 ya) H. sapiens fossil found in Ethiopia.

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