The Evolutionary order of Humans

Important Dates in Earth’s History

Most scientists date Earth’s origin to around 4.5 billion years ago

222 million years ago, mammals first appeared

200 mya-65 mya dinosaurs roamed the Earth

65 mya- first primates 4.5 million years ago- first possible

human ancestor appeared

All information on pre-history human ancestors comes from fossil finds of skulls and bones

Most recent findings came in 1994 when new bones were found in Ethiopia and new species was discovered:• Ardipithecus ramidus

Ardipithecus ramidus Lived 4.4 mya Cranium the size of

present day chimp Found near present

day Ethiopia Diet included

mostly nuts and vegetation

Big deals about Australopithecus

Believed to have been 4 species

Lived 3.5 mya Walked on 2 legs

(hole in bottom of head that spinal column goes into)

Short, hunched over but walked upright

Small brain (size of baseball)

Molars have heavy enamel- more diverse diet

Sexual dimorphism Altricial infants-

children that require a lot of care when born

Australopithecus Afarensis

Homo- Species Homo Habilis – “handy man”

• 2.5 mya- 1.8 mya• 2 subgroups- smaller and larger• Rounded skull, bones are thinner• Large canines• Earliest known to use stone tools. Known as

Oldowan tools• Found in East and South Africa

Homo Habilis- Skull and Tools

Homo Erectus- “Erect Man” 1.7 mya - .5 mya Increase in brain size (2x

Australopith) Shortened face (beginning of chins) Size increases (males up to 5’10”) Sexual dimorphism decreased Use of different tools like hand-axe

(Archeulian) Discovered fire First to hunt for subsistence

Homo Erectus

BIG DEALS in Hominine History

First hominines out of Africa are Homo erectus

First use of fire (700,000 yrs ago) Ate meat – more scavenging than

hunting Smaller pelvis = smaller babies

Archaic Homo Sapiens Significant increase in brain size Less robustivity Increase in tool sophistication Bones found all over most of the Old World Still shorter than modern humans Mousterian tools Hunters Thought to have possibly buried dead and

have some form of organized religion and language

Modern Homo Sapiens Appeared 35,000 yrs ago Taller than all other Homines Less robust Rounded skull Higher, less sloped forehead Relatively cultured Extensive tool use

“BIG DEALS” Art Body decoration Demise of large animals all around

the world Cultural explosion

Archaic vs. Modern