nil.enroll(aetheric_username, quantum_class_id) (adric) wrote,
nil.enroll(aetheric_username, quantum_class_id)

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Anth, 23 Jan 2002

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

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