인간 진화사

인간의 진화사

Major events

13,700 mya

  • The Big bang - Origin of Universe.

4,567 mya

  • Earth forms.

3,700 mya

  • First life emerges.

1,200 mya

500 - 450 mya

  • First vertebrates.

365 ya

  • Fish evolve lungs and walk on land.

248 - 208 mya

  • First small mammals and dinosaurs evolved.

208 - 65 mya

  • Large dinosaurs flourished.

114 mya

  • Placental mammals evolve.

85 mya

  • First primates evolve.

65 mya

  • Dinosaurs go extinct, mammals then increase in size and diversity.

35 mya

  • First apes evolve.

10 - 7 mya

8 - 6 mya

  • The divergence of our hominid ancestors from the Great Apes.

4.4 mya

  • Emergence of Bipedalism to avoid competition with monkeys(Australopithecus anamensis, Australopithecus afarensis - aka Lucy)
    • Upright posture and full eye contact provided room for the emergence of the first gestural signals.
    • The forearms can then be used to hold tools and weapons.
    • The move to Bipedalism opened up major cognitive challenges in terms of the control of the hands.

4 mya

  • Major reorganization of Parietal cortex.
    • Reduction of primary visual striate cortex
    • The enlargement of Extrastriate parietal cortex, Angular gyrus, and Supramarginal gyrus
  • Such changes in the Parietal cortex support three basic cognitive functions.
    • Processing in the dorsal stream (see Two-streams hypothesis) of the visual field is important for representing actions of the other in terms of one’s own body image.
    • The association area of parietal maintain a map of the environment for navigation in the new bipedal mode.
    • The Supramarginal gyrus is involved in Face perception. Expansion of this area would facilitate the development of social patterns and memory for social relations. -> It played a large role during the next period of evolution (social cohesion).

3.5 mya

  • The hominids in East Africa went through an expansion of their range and a proliferation of species.
    • Tight competition with range contraction leads a set of targeted neural-behavioral adaptations. - the subordination of vocal system to cortical control.
    • Side-effect of the cortical control over vocalization: local forms of communication like those of song-birds.
  • How about the Great apes in West Africa?
    • The different requirements on group size in their arboreal habitat
    • No bipedal gait and its resultant improvements in face-to-face communication.

3 mya

  • The Australopithecus evolve in savannas of Africa.
  • A gradual tripling of brain size.
    • Massive changes in the interconnectedness of the Frontal lobes.
    • Changes in the linkage of vocal production to motor and emotional areas.
    • Linkages of the visual areas to motor areas.
    • Expansion of many older areas, including the Cerebellum, Basal ganglion, and Thalamus.
    • (these changes are basis for an ability to produce actions through movement and sounds throught vocalization)

2.5 mya

  • Earliest stone tools - Oldowan (found in Ethiopia and Kenya, Africa); used to butcher carcasses for meat and to extract marrow from bones; linked with Homo habilis.

2 mya

  • The remarkable expansion of habitat to all of Africa and Eurasia by Homo erectus.
  • Brain expansion ran up against the Bipedalism, forcing a series of adaptations in female anatomy, parturition, and child rearing.
  • New forms of symbolic communication system - the spontaneous interaction of vocalizations, postures, and gestures in specific social and pragmatic contexts.
    • Vocalizations had not yet been systematized. Gestural and postural patterns probably played a more central role.
    • But their iconic and situated nature may have seved as a barrier to abstract systematization.

1.8 mya (the end of the Pliocene epoch, and the beginning of the Ealry Pleistocene epoch)

  • Homo erectus had achieved dominance over its hominid competitors.
  • The onset of the glaciations of the Pleistocene epoch.
  • Homo erectus spread beyond African Homo erectus. The first migration from Africa.

1.6 mya

  • First evidence; likely hearths; linked with African Homo erectus.

1.5 mya

  • Invention of Acheulean hand axe; linked with Homo ergaster - tall stature, long limbs.

1.2 mya

  • Brain expansion in homo line begins.

1 mya

  • Hominids spread to Europe.

800,000 ya

  • Crude stone tool kit - found in Spain, linked with Homo antecessor.

780,000 ya (middle Pleistocene epoch begins)

600,000 - 400,000 ya

  • Long crafted wooden spears and early hearths; linked with Homo heidelbergensis found in Germany.

500,000 - 100,000 ya

  • Period of most rapid brain expansion in Homo line.

300,000 - 50,000 ya

  • Gradual evolution of new system that supports a set of phonological contrasts.
    • A major expansion of the parts of the vertebrae that carry nerves for the intercostal muscles. (p384)
    • Loss of the canines.
    • Adaptation of the arytenoids.
    • Bending of the vocal tract.
    • shaping of the musculature of the tongue.

200,000 ya

  • The emergence of Homo sapiens and Mitochondrial Eve.

200,000 - 30,000 ya

  • Neanderthals flourish in Europe and western Asia.

126,000 ya

  • Late Pleistocene epoch begins.

100,000 - 50,000 ya

  • Exodus from Africa - second major migration. See also Out of Africa theory

70,000 ya

  • Near extinction that brought the number of our direct ancestors down to only 10,000 individuals worldwide.

40,000 ya

  • Explosion of diverse stone tools, bone tools, blade tools, well-designed fireplaces, elaborate art; found only among Homo sapiens, not among Neanderthals.

40,000 - 35,000 ya

  • Homo sapiens (Cro-Magnon) arrive in Europe.

30,000 ya

  • Neanderthals go extinct.

27,000 ya

  • Homo sapiens colonize entire planet; all other hominid species are now extinct.

10,000 ya (Holocene epoch begins)

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See also

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