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Paleoanthropology - Coggle Diagram

- - - - (Darwin and Dart) expansion of savannah forced bipedalism as a more effective form of locomotion and long-term aridification were drivers for early diversification
      - marine and terrestrial records indicate cooling and dry conditions and isotonic records suggest increase grasslands
    - - (Elisabeth Vbra) specialist eaters are confined to single area and have greater extinction risk in extreme conditions compared to generalists
      - Faunal evidence in Turkana basin and Cape Floristic Belt show extreme climate changes increase extinction rate
    - - (Rayner) forested environments influenced bipedalism development
      - Pollen evidence from Kakapansgat suggests hominins occupied it, lack of evidence of knuckle walking
    - - (Potts) hominin evolution does not respond to habitat changes but rather long-term environment unpredictability, so different groups would experience different degrees of natural selection
      - supported by large climatic variability and higher survivability of generalists, also the larger time-scale extinction events
    - - East African Rift system and changes in deep lakes drove diversification; the water contents of lakes were affected by monsoonal rains and solar precessional cycles
      - changes in solar precessional cycles increased th monsoonal system causing more rain in East Africa
  - - - energy conservation: stacking majority of weight around centre of gravity reduces muscle engagement, stride gaiting is more energy efficient and allows travelling further
      - Thermoregulation: less surface area in direct sunlight, so less need for cooling mechanisms (like sweating, so less water loss)
      - free hands: easily gather and carry and enabled further specialisation
    - - foramen magnum positioned inferiorly so it rests on top of verterbrate for balance and support
      - S shape spinal curve due to pressure exerted on spine
      - shorter upper limbs
      - pelvis is shorter and bowl shaped for support
      - large femoral head and longer neck to absorb stress
      - valgus angle of knee helps balance
- - - - originally just associated with Homo species, but Orangutans make rain hats and gorillas use measuring sticks
      - indirect evidence- striking bone and evidence found at Olduvai Gorge in Tanzania
- - - - found in Chad, ~7mya
      - only Cranium- ~350cc, foreword placed foramen magnum
    - - found in Kenya, 6mya
      - all post cranial, femur is similar to later hominins and elongated femoral head, smaller thick bones
    - - Found in Ethiopia, 4.4mya
      - ~325cc, forward placement of formaen magnum, small canines (derived) and less prognathism
      - Long arms (but no knuckle walking), short iliac blade, similar ischium to chimps and grasping feet
    - - Dikika bones (butchery marks from 3.4 mya)
      - Oldowan industry (2.6 mya and associated with Homo habilis because of the knapping skill)
  - - - East Africa, 4 mya
      - 370cc, less developed dentition (larger canine and U-shaped dental arcade)
      - thicker distal and proximal tibia (likely for weight bearing due to bipedalism) and arboreal traits in arms
    - - ~400cc but bipedal (so bipedal before encephalism when originally though to be the other way round)
      - Less developed- prognathic, robust facial features (strong chewing musculature), U shaped dentition, long arms, curved phalanges, muscled shoulders(arboreal?), narrow upper thorax (vegetarian?)
      - more derived- short iliac blades that extend anteriorly, angled femur, tibia for weightbearing, longitudinal arch and non-divergent hallux (found in footprints)
      - Tanzania, 3.5 mya
    - - Ethiopia, 3.4 mya
      - robust mandible, small dentition (thick enamel), larger mandible and projecting cheekbones
      - debate on whether it is a different species
    - - 500cc, less prognathic, smaller canines and incisors but larer molars
      - lumbar curve and 6 lumbar vetebrae (5 normally, but could be anomaly
    - - Ethiopia, 2.5 mya
      - 450cc
      - found near long femur and long arms, but still arboreal
    - - South Africa, 2 mya
      - 400cc, smaller molars and premolars, gracile mandible
      - smaller bone bone size (shortened ilium and ischium), but long arms and narrow upper thorax, arguments that it shows modern hand morphology
  - - - 400cc, large dentition (but only few teeth found) and distinct sagittal crest
      - Ethiopia, 2.5 mya
      - proximal tibia (bipedalism
    - - 500cc, massive cheek teeth but small crowded front teeth
      - flared zygomatics and flat, concave face; termed hyper-robust
    - - 500cc, large cheek teeth, small anterior teeth and thick bone around nose
      - in between Australopithecus and hyper robust
    - - large, broad dish shaped face, large mandible and zygomatic arches
      - large posterior dentition, thick enamel, robust jaws, and flared zygomatic arches- linked to tough foods
- - - - large brow ridge, occipital bun, elongated mandible, hyoid bone higher, midfacial prognathism, large orbits
      - strong arm, barrel chest
      - cold adaptations
        
        shorter and stockier
        
        large nasal aperture
    - - Mousterian industry
      - used debitage to make tools
      - scarred stone tips mean hunting large animals at close range
      - created ornaments and paintings
  - - - flat faces, smaller orbits and nasal aperture, high vaulted and rounded braincase, less perpendicular nasal bone
      - tall and more gracile, long legs with shorter arms
      - Cranial
        
        high forehead which reduces supraorbital torus
        
        Parietal lobes bulge outwards
        
        gracile facial bones
    - - emergence of sapiens does not correlate to emergence of special tools
      - Aurignacian industry
  - - - long broad face, prognathic, elongated skull, teeth similar to habilis
      - wide chest and hips
    - - between 180-36 kya
      - stone and bone tools
  - - - many geographical points of origin
      - speciation prevented gene flow between the regions
      - variation in fossils is caused by different selection pressures
      - explians the disappearance if Neanderthals and denisovans
    - - one point of origin and then migrationout of Africa and replaced other archaic species
      - there is no continuity between species in local region
      - there is greatest genetic variation in African communities
    - - if no interbreeding then all Neanderthal DNA should be equally similar to modern humans but it is more similar to non-African populations
      - so there was interbreeding between Neanderthals and Sapiens, and DNA suggests migration back and forth
      - Archaic species leaves Africa and evolve into Neanderthals, Denisovans, Sapiens. The humans interbreed with Neanderthals and some move towards Melanesia and interbreed with Denisovans
- - - - Ethiopia, 2.8 mya; Tanzania, 1.7 mya; Kenya, 1.9 mya; SA, 1.7 mya
      - 600cc, smaller teeth adn more parabolic dental arcade, less prognathism but less derived postcrania
      - curved fingers, long and muscled arms, longitudinal arch
      - lots of variation in fossils and suggested splitting into habilis and rudolfensis (which had larger brains); some kept them together and argued dimorphism, adaptation and developmental plasticity
      - Australopithecus?
        
        analysis of strength of limb bones suggested that it was more adapted to arboreal (but was still bipedal)
        
        fossil discovery revealed short stature
      - Stone tools
        
        more common after 2 mya
        
        the rock selected must be struck with hammerstone at correct angle (this requires selection and planning)
        
        studies of animal bones are cracked suggesting marrow extraction (exploitation of a niche for protein) and used to process plant material
    - - 2.5-1.9 mya
      - 750-800cc, large flat face, wide, deep zygomatics and robust mandible
      - large front teeth, intermediate molars
    - - 1.9mya-110kya
      - encephalisation (900cc), smaller teeth, had a occipital torus (horizontal ridge), thicker cranial bones, sagittal keel, less prognathism
      - body size and proportions similar to modern day, fully bipedal, likely to be effective at sweating, long, muscled legs
      - 2 types
        
        found in Africa and Asia, some argue Asian should be erectus and African ergaster
        
        African- 1.8-1.4mya- thicker cranial bones, absent sagittal
        
        Asia- Java Man in Indonesia; Peking man in China; pronounced bow ridges and sagittal keel
      - Fossil records
        
        debate as large variation (debate on size accuracy compared to Nariokotome boy's)
      - less sexual dimorphism which signifies changes in social organisation
      - Tools
        
        part of Acheulean tool industry
        
        technique of bifacial flaking (which requires more skill since symmetrical)
        
        likely used degradable material (like bamboo) since only Oldowan tools are found at erectus sites
        
        ash also found at sites
      - Diet
        
        "expensive tissue hypothesis"- a smaller gut allows for a larger brain without the need to increase metabolic rate
        
        studies of tooth surface and wear patterns indicates a variety diet, which makes sense becasue of the changing environment
        
        climate change meant new food was available
      - thought to be first hominin to leave Africa, helped by larger brain, meat diet, powerful legs
    - - 1.2mya-800kya
      - 1000cc, big teeth and derived shape
      - potential hunting and communal division of labour
    - - 700-200kya
      - first to live in cold climates, routinely hunt and build shelter
      - 1200-1500cc, high forehead, large brow ridges, reduced postorbital waisting
      - robust post cranial and over 1.8m
    - - debate on whether separate species or variation
    - - 500cc, prognathic, smaller teeth, gracile mandible
      - slender, human hands and feet, Australopithecus hips
    - - 50kya, but stone tools found are older
      - 1.1m tall