Buried Cities W6
February 16 , 2017
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Story of Human Origin = Story of Climate Change
Expansion of woodland and savanna expand in Africa 6 million years ago led to the evolution of the first
hominins
-Moist tropical forests shrink, and are replaced by dry woodland areas
The earliest known Hominin date to 6-7 MYA
- “Toumai”
-Brain size was smaller than a chimp
What makes a Human a Human?
-Bipedal Locomotion (walking on two legs)
-Begins to appear 6-7 MYA with early hominins/australopithecines
-Larger Brain
-Begins to appear in genus Homo around 2 mya
-Long Juvenile Period
--Begins to appear in genus Homo around 2 mya
-Complex Foraging Techniques
--Begins to appear in genus Homo around 2 mya
-We Depend on Elaborate Material Culture
Lucy
-Lived in a habitat that ranged from woodland to savanna
-Discovered by an ASU professor
-Fully Bipedal
-If you look at skull and teeth she is very ape like
-Much smaller than humans now, longer arms and smaller brain
-Behavioral evidence of Bipedalism, footprints in the archaeological record
-Female: 3’6”, 65 pounds.
Bipedalism
-Why did we evolve to Bipedalism?
-Why was it favored in natural selection?
-It is an efficient way to travel on the ground
-Good way to jeep cool in open-country
-Direct posture (standing up) reduces the amount of heat stress put on the brain, and allows you to
cool down quicker
-Hands free for carrying things, tools, food, etc.
-Efficient for harvesting fruits from small trees
Australopithecines
-Probably still spent some time in the trees
-Ape-sized brains, 450 cubic centimeters
Stone Tools
-Evidence of stone-tool-assisted meat consumption ~ 3.4 million years ago
- “Lomekwian Tools”
Complex Foraging Techniques
-Human Hunting
-77 mammalian species
-21 reptile species
-14 fish species
-150 bird species
-Learning to hunt and extract resources takes many years
