Human Evolution

Did we evolve from apes?

Humans DID NOT evolve from apes we have a common ancestor

Scopes “Monkey Trial” 1925 John Scopes a Dayton Tennessee Biology teacher taught about the theory of evolution to his students despite it being against the law. Scopes was arrest, tried, and found guilty. Two years later Scope’s guilty sentence was overturned. The topic of evolution did not appear back in school books until the 1960s.

Apes Apes include: 1)Gibbons 2)Orangutans 3)Gorillas 4)Chimpanzees

Chimpanzee Characteristics that are similar to humans -Make and use simple tools pg 402 -Can learn ex: can be taught sign language -Self aware beings ex: chimps in front of a mirror

Human Branch of Primate Tree -Occurred about 5 to 7 million years ago - This branch is called Hominids

5 Major Traits of Hominids 1)Increased brain size 2)Shorter jaws 3)Bipedal posture (upright posture to walk) 4)Reduced size difference between the sexes (human males average about 1.2 times the weight of females) 5)Family structure (long term bonding between mates, newborns dependent upon mothers, long period of parental care)

Two Main Groups of Hominids 1)Australopithecus 2) Homo

Australopithecus afarensis Fact Scientists argue if this species really is the closest relative to the Homo branch on the phylogenetic tree Australopithecines overlapped in time with species of Homo

Australopithecus afarensis Characteristics 1)Bipedal 2)Arms are long in proportion to body size (suggests arboreal locomotion might of occurred) 3)Skulls are ape like 4)Long jaws 5)Small brain volume

Famous Australopithecus afarensis Lucy Skelton of a young female found in Ethiopia in 1974 Characteristics a)3 feet tall b)Arms long but her hands and feet like modern day humans c)Large head d)Jaw and forehead stuck out from her face

Why is Lucy Famous? She is the oldest (3 million years old), most complete erect walking human ancestral skeleton found to date

Laetoli Footprints Facts: Hominid footprints found in Tanzania in 1976 that dated back 3.6 million years Oldest evidence of bipedal walking Scientists believe these footprints were made by an Australopithecus afarensis

Homo habilius FIRST species of the homo genus to appear Characteristics 1)Reduction in protruding face (jaw underneath the brain) 2)Smaller molars 3)Associated with Oldowan tool industry

Homo sapiens are the sole remaining member of the hominid family tree This is us!