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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?