Anth, 23 Jan 2002

[adric]

Early bipedes:

• fossils are found in Africa


• the Great Rift Valley


• is growing hourly(!) (Congo vulcanism)


• bipedes fossils mostly on east side of rift


• only one early bipede on west side (Chad)


• plenty of quadrapedial primates on east side but no chimps or gorilla fossils


• map: fossil finds: Chad, Ethiopia, Kenya, Tanganyika, S Africa


• Why bipedialism (theories)?
  
  
  
  • savannah development (8-5 e6 yBP) -> added height
  
  
  • tool use while moving
  
  
  • cooling / heating (biped hair retention in areas: head)
  
  
  • (heavier) hair loss -> development of sweat glands, make use of convection
  
  
  • sweating forces increased water use -> travel between watering holes
  
  
  • more energy efficient than quadrapedes
  
  

Australopithecines:

• A. aferensi (sp!) Lucy:
  
• Leg/hip joint 120 degree angle:
  
  
  
  • hip tilts, freeing leg, stiffen knee, one foot lands in front of other foot
    
  • -> (ideally) single line of tracks
    
  • models: are taught to walk this way
    
  • baseball players: are trained this way, cf outfielder Andrew jones
    


• S-curve shaped spine (double curve)
  
• legs length increases
  
• wider pelvis
  
• great toe in alignment with other toes
  
  
  
  • levers foot off the ground in walking
    
  • diff chimp
    


• arch is beginning to develop
  
• spinal column opening in skull is underneath rather than in the back
  
• even teeth are different
  
• image: Museum of Natural History in NY
  
• neck-down look very human
  
• brain capacity about the same as a chimp
  

Family tree

• in CP p 38
  
• over 2e6 (almost 3) y from bipedeemergence to homo


• brain size is essentially unchanged
  
• 1.8 - 1.6 e6 ybp: paranthropus, homo
  
• brains notably enlarged in frontal lobes: fine motor, learning language,
  
• (fire dates to 500 - 800 e3 ybp)
  
• Why?
  
  
  
  • brains used more..
    
  • more information passing down..
    
  • seasonal migration..
    
  • more complex motor function..
    
  • developed a feedback loop
    


• image: homo habilis with pebble tool and scraper
  
• scraper tools (1e3 ybp) -> multipurpose tools
  
  
  
  • scraper: skin hides, scrape meat from carcass
    
  • core tool: crack nuts, shells, bones -> marrow (protein and fat)
    


• found with cracked/cut animal bones
  
• stone tools used to cut meat and marrow from other animals kills
  
• protein and fat are nutrive: "brain foods"
  
• stimulates brain growth -> better tools -> nutrients -> brain growth -> ad infinitum
  
• cultural development begins with new brain capacities
  
• why long term memory so imporant?
  
  
  
  • pre-literate
    
  • culture builds upon itself -> "snowballs"
    
  
  

*geographical location*

• P. boisei, H. Habilis, H. ergaster, H. rudolfensis, H. erectus
  
• all lived as contemporary
  
• H. erectus first to migrate from Africa
  
• map: Eastern hemisphere.
  
• erectus: hand axe
  
• weather (climate) is improving, but slowly
  
• move mostly west and sw
  
• through SE Asis across land to Java
  
• warming cut Java and islands off from SE Asia
  
• HE pockets were caught
  
• HE survived up to 30e3 ybp
  
• north to China: Peking Man
  
• Zhoukoudian:
  
  
  
  • multi-generational dwelling (cave), large group 45 individuals
  
  
  • no evidence of intentional burial
  
  
  • large chunks of skull had been removed:
    
    
    
    • speculation: brain eating funeral ritual
      
    • or cannibalism
      
  
  
  • fire ! -> essential base technology: controlling heat
  
  
  • cook meat, keep warm, ward off other animals
  
  
  • boosts socialization -> improve comms -> building culture
  
  
  • fossils were lost in WWII but skull casts were sent out of country
  
  
  • may have made it to Shanghai
  
  


• back to tree


• warmer still : antecessor enters Europe


• H. antecessor
  
  
  
  • ?-> H. heidelburgensus
  
  
  • ?-> H. neanderthalus
  
  
  • ?-> H. sapiens
  
  
  
  
• mitochondrial DNA research -> one family(!!) 200e3 ybp


• (mito. DNA, (non-nuclear) passes on from mother without alteration)


• H. Erectus now thought to be an Asian variant
  
• Europe: H. antecessor -> ..
  
• 1970s conference MofNH,NY: began collection of forms rather than individual fossil names