Chapter 2: The Star Wars BarChapter 2: The Star Wars Bar

How many pre-human skeletons/skulls have we discovered so far?How many pre-human skeletons/skulls have we discovered so far?

2000 for a 5 million year period

What are the differences between splitters and lumpers among paleoanthropologists?

What are the differences between splitters and lumpers among paleoanthropologists?

splitters: think small differences are important-->split into many separate species

lumpers: think small differences unimportant--> lump into a few large species with wide variation

Human Evolution as a BushHuman Evolution as a Bush

Human Evolution as a BushHuman Evolution as a Bush

What is the difference between picturing evolution as a tree or a bush?

What is the difference between picturing evolution as a tree or a bush?

tree: Homo sapiens seen as a goal [fruit] of evolution

bush: Homo sapiens just one of many possible outcomes-->chance and environment determine outcome

For how long has our species been the only hominid on earth? For how long has our species been the only hominid on earth?

30,000 years

How does this affect our view of the probability of evolution?How does this affect our view of the probability of evolution?

We tend to see ourselves as goal or peak of evolutionary process

We assume there has always been just one single hominid on earth-->that is exception, not rule

The March of Evolution ~ NOT true!The March of Evolution ~ NOT true!

How does the Star Wars bar scene help us think of evolution differently?How does the Star Wars bar scene help us think of evolution differently?

Aliens from all parts of galaxy co-existing at one time

Hominids at different stages of evolution co-existing

The Star Wars CantinaThe Star Wars Cantina

The Star Wars Cantina: The Fossil EvidenceThe Star Wars Cantina: The Fossil Evidence

Why did Charles Darwin think Africa was the place to look for evidence of early human evolution?

Why did Charles Darwin think Africa was the place to look for evidence of early human evolution?

Oldest known civilizations in Africa: Egypt

Biggest continent with widest variety of life forms and hospitable climate

Native habitat for most human-like apes: gorillas and chimpanzees

Discoveries of Human Ancestors in AfricaDiscoveries of Human Ancestors in Africa

How popular was Darwin's hypothesis in the 19th century? Where did people prefer to look? Why?

How popular was Darwin's hypothesis in the 19th century? Where did people prefer to look? Why?

19th century European racists had prejudiced views of Africans

Asia most populous continent with highly respected civilizations

Why were the discoveries of Robert Broom in Africa so important?Why were the discoveries of Robert Broom in Africa so important?

confirmed Africa as home of original humans

several species of Australopithecus found there

Robert BroomRobert Broom

What were the most favored habitats [kinds of places] of Australopithecus? What were the most favored habitats [kinds of places] of Australopithecus?

forest fringesopen grasslandswoodlandsherbivorous diet supplemented by

scavenging meat from dead carcasses

The New African EnvironmentThe New African Environment

Robert Dart’s Discovery: The Taung ChildRobert Dart’s Discovery: The Taung Child

What was Robert Dart's hypothesis about the social behavior of Australopithecus?

What was Robert Dart's hypothesis about the social behavior of Australopithecus?

early human ancestors were violent, bloodthirsty killer-apes

Reflected violent decades from World War I through World War II: 1914-1945

What was his evidence for this thesis?What was his evidence for this thesis?

he found concentrations of pierced human skulls

concluded they were brought there by ritual killing

What is the preferred hypothesis explaining this evidence today? What is the preferred hypothesis explaining this evidence today?

holes in human skulls were inflicted by animals who preyed on vulnerable hominids

“Kidnapping” the Taung Child’s“Kidnapping” the Taung Child’s

What was so unconventional about the training and education of Louis and Mary Leakey?

What was so unconventional about the training and education of Louis and Mary Leakey?

parents were Christian missionaries working in Africa

both lacked official university degrees or institutional sponsor

Why was "Piltdown Man" so eagerly accepted as a genuine discovery by paleoanthropologists of the early 20th century?

Why was "Piltdown Man" so eagerly accepted as a genuine discovery by paleoanthropologists of the early 20th century?

it fit preconceived model: big brain with ape body

located in culturally prestigious Europe-->most "civilized" continent

The Piltdown Hoax: So Believable!The Piltdown Hoax: So Believable!

What are the oldest surviving human tools? What are the oldest surviving human tools?

primitive tools used to smash nuts and bones

The Oldest Stone ToolsThe Oldest Stone Tools

How do we know they were even made by anyone?How do we know they were even made by anyone?

chipped flacks used as cutting edges for flesh

high density of smashing tools couldn't be the result of chance

What were the two most significant new features of Homo habilis? What were the two most significant new features of Homo habilis?

Homo habilis: "handy man"Brain size: 700 cc. [Australopithecus=

500cc]

Hominid Brain GrowthHominid Brain Growth

Homo habilis 1Homo habilis 1

Homo habilis 2Homo habilis 2

Homo habilis 3Homo habilis 3

Homo habilis 4Homo habilis 4

Homo habilis 5Homo habilis 5

Homo habilis 6Homo habilis 6

What were the major differences between the two types of hominids about 2 million years ago?

What were the major differences between the two types of hominids about 2 million years ago?

vegetarians: Australopithecusmeat-eating scavengers: Homo habilis

What were the important environmental changes about 2.5 million years ago that sparked the emergence of Homo habilis?

What were the important environmental changes about 2.5 million years ago that sparked the emergence of Homo habilis?

period of intense weather changebouts of warming followed by intense

cooling lower temperatures--> further shrinking

of forestsomnivores ate greater diversity of food--

> won out over more specialized herbivores

The Range of Habilis’ HabitatThe Range of Habilis’ Habitat

Where is Olduvai Gorge?Where is Olduvai Gorge?

former lake lake region in Kenya

Olduvai Gorge in KenyaOlduvai Gorge in Kenya

Why is it such a rich site for the discovery of earlier hominids? Why is it such a rich site for the discovery of earlier hominids?

possessed rich bio-mass to support large animal population--> many surviving fossils

near water holes and nearby volcanoesnow parched to reveal lower layers

each spring

How was the increased brain size of Homo habilis related to its new kind of diet?

How was the increased brain size of Homo habilis related to its new kind of diet?

could make more efficient toolscould better locate likely animal

carcassescould gain access to protein-rich bone

marrow

Homo habilis using stone tools to eat bone marrowHomo habilis using stone tools to eat bone marrow

How did this new brain and diet affect Homo habilis' chance of surviving in a new, unstable environment?

How did this new brain and diet affect Homo habilis' chance of surviving in a new, unstable environment?

highly concentrated bone-marrow protein necessary for rapid brain growth

bone marrow available at all seasons

Kenyan Stamps on Human EvolutionKenyan Stamps on Human Evolution

Where Does Homer Fit?Where Does Homer Fit?